JP2010048159A - Oil supply control device - Google Patents

Abstract

Provided is an oil supply control device capable of improving engine fuel consumption and suppressing a decrease in cooling capacity of an engine due to oil by simple control when fuel cut of the engine is executed. .
An engine immediately before fuel supply control is performed by an oil pan, a pump mechanism, an oil supply control unit, an oil recirculation unit, an OSV, a fuel supply control unit of an ECU, and the fuel supply control unit. An engine load determination unit that determines whether or not the load of the engine is higher than the reference load. When the engine load determination unit determines that the engine load is higher than the reference load, the oil supply control unit When the engine load determination unit determines that the engine load is lower than the reference load, the oil supply control unit opens the OSV and passes a part of the oil flowing through the oil passage through the oil return passage. And returning to the pump mechanism.
[Selection] Figure 5

Description

  The present invention relates to an oil supply control device, and more particularly to an oil supply control device capable of improving fuel efficiency by controlling the supply of oil when fuel cut control of an engine is being executed.

  In an engine provided in a vehicle such as an automobile, oil stored in an oil pan is sucked by a pump mechanism and pumped into an oil passage such as a main oil gallery, and a piston, intake / exhaust cams are passed through the oil passage. Oil is supplied to lubrication parts such as shaft and crankshaft journals. In addition, the oil supply control device controls the oil supply of the pump mechanism according to the operating state of the engine, and lubricates and cools these lubrication parts with an appropriate amount of oil, while reducing the load on the pump mechanism, The load on the vehicle is reduced to prevent fuel consumption from deteriorating.

Conventionally, as an oil supply control device of this type, an oil pump that can adjust the output of discharge pressure or discharge amount is provided, and the engine is fuel cut by fuel cut means that cuts fuel supplied to the engine. Some have been known to adjust the output of an oil pump (see, for example, Patent Document 1).
In this conventional oil supply control device, when the engine is fuel cut, the output of the oil pump is reduced to lighten the load on the oil pump, thereby reducing the load on the engine and rapidly acting on the vehicle. An increase in the speed reduction force is suppressed, and a smooth deceleration of the vehicle is obtained. In addition, by reducing the load on the oil pump and reducing the load on the engine, the fuel consumption of the engine is prevented from deteriorating.

On the other hand, when the fuel cut is completed, fuel is supplied to the engine, the output torque of the engine increases, and the vehicle can be accelerated. At this time, the output of the oil pump is controlled to increase, and the load of the oil pump increases. When the load of the oil pump increases, the load of the engine also increases, so that rapid acceleration of the vehicle is suppressed and smooth acceleration of the vehicle is obtained.
JP 2004-124973 A

However, in such a conventional oil supply control device, when the engine is fuel cut, the output of the oil pump is uniformly reduced to lighten the load of the oil pump. Therefore, there is a problem that the amount of oil supplied to the oil is reduced and sufficient lubrication and cooling are not performed. Further, since the oil pressure of the oil jet that injects oil toward the piston is lowered and the oil jet injection is stopped, there is a problem that the cooling ability of the piston by the oil jet is lowered.
Even when a fuel cut is made, there is a region where the engine load is relatively large and the piston needs to be cooled by an oil jet. When fuel cut is performed in such a cooling-required region, the output of the oil pump is lowered, and there is a problem that it is not possible to meet the piston cooling request.

  An object of the present invention is to solve the above-described conventional problems and achieve the following objects. That is, the present invention provides an oil supply control device that can improve the fuel consumption of the engine when the fuel cut of the engine is executed, and can suppress a decrease in the cooling capacity of the engine due to the oil by simple control. The purpose is to provide.

  In order to achieve the object, an oil supply control device according to the present invention includes: (1) an oil pan that stores oil, and a pump that supplies the oil stored in the oil pan to an engine lubrication unit via an oil passage. An oil supply control device comprising a mechanism and an oil supply control unit that controls the supply of oil, wherein the oil return passage branches off from the oil passage and returns a part of the oil in the oil passage to the pump mechanism An oil recirculation section, an oil switch valve provided in the oil recirculation section for opening and closing the oil recirculation passage, a fuel supply control section for controlling the supply of fuel to the engine according to the operating state of the engine, An engine for determining whether or not the engine load immediately before fuel cut by the fuel supply control unit is higher than a reference load. An engine load determination unit, and when the engine load determination unit determines that the engine load is higher than the reference load, the oil supply control unit closes the oil switch valve, and the engine load determination unit When the engine determines that the load on the engine is lower than the reference load, the oil supply control unit opens the oil switch valve so that a part of the oil flowing in the oil passage is recirculated to the oil. It is comprised from what recirculate | refluxs to the said pump mechanism through a channel | path.

  With this configuration, when the fuel cut is started based on the command from the fuel supply control unit, the engine load immediately before the fuel cut is compared with the reference load based on the command from the engine load determination unit, and the engine load is It is determined whether or not the load is higher. When it is determined that the engine load is higher than the reference load, the oil supply control unit closes the oil switch valve, and a part of the oil circulating in the oil passage is returned to the pump mechanism through the oil return passage. Therefore, the hydraulic pressure in the oil passage is not uniformly reduced by the start of the fuel cut as in the engine in the prior art. As a result, the oil pressure required for the oil jet that injects oil toward the piston can be ensured, and the problem that the cooling capability of the piston by the oil jet is reduced during the fuel cut control is solved. In addition, the amount of oil supplied to the engine lubrication part during fuel cut control is reduced, and the problem of insufficient lubrication and cooling is solved.

In addition, when it is determined that the engine load is relatively smaller than the reference load during the fuel cut control, the oil supply control unit opens the oil switch valve, and a part of the oil flowing through the oil passage is Since the oil is recirculated to the pump mechanism through the oil recirculation passage, the pressure of the oil discharged from the pump mechanism is reduced, and the work rate of the pump mechanism is reduced.
In this case, since the load of the pump mechanism connected to the crankshaft is reduced, the friction of the crankshaft is reduced, the load on the engine is reduced, the fuel consumption rate is improved, and so-called fuel efficiency is improved.

  According to the present invention, an oil recirculation portion branched from an oil passage is formed, and an engine load is controlled during fuel cut control of the engine with a simple structure and simple control in which an oil switch valve is provided in the oil recirculation portion. Therefore, it is possible to provide an oil supply control device capable of coexisting engine cooling and lubrication with oil and fuel consumption rate improvement, that is, fuel efficiency improvement. .

Hereinafter, an oil supply control device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view of an engine of a vehicle to which an oil supply control device according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram showing the flow of oil and each lubricating portion inside the engine. FIG. 3 is a circuit diagram of the pump mechanism, and FIG. 4 is a partial cross-sectional view of a cylinder block that houses a piston.

First, the configuration will be described.
As shown in FIG. 1, an engine 1 includes a piston 2 housed in a cylinder, a variable valve timing mechanism (VVT) 3, a crankshaft 4, an oil supply control device 5, a cylinder head, The engine block 6 includes a cylinder block and a crankcase, a cooling unit 7 that cools the inside of the engine 1, and a fuel injection device (not shown) that directly injects fuel into the cylinder.

  The piston 2 constitutes an in-line four-cylinder engine 1 including other three pistons (not shown). The engine 1 is not limited to an in-line four-cylinder engine, and may be a single cylinder or a multi-cylinder arranged arbitrarily, and may be a liquid such as a hydrocarbon that can be mixed with air, such as a gasoline engine or a diesel engine. A known engine using gas as fuel may be used.

  The VVT 3 includes an intake side hydraulic controller 33 that is connected to the intake camshaft 31 and drives the vane type actuator 32, and an exhaust side hydraulic controller 36 that is connected to the exhaust camshaft 34 and drives the vane type actuator 35. Has been. The intake side hydraulic controller 33 and the exhaust side hydraulic controller 36 are connected to the crankshaft 4 via a chain 37 and are driven by the power of the crankshaft 4.

  An intake side oil control valve (OCV: Oil Control Valve) 33c is connected to the intake side hydraulic controller 33 so that the hydraulic pressure supplied to the intake side hydraulic controller 33 is controlled. An exhaust side oil control valve (OCV) 36 c is also connected to the exhaust side hydraulic controller 36 so that the hydraulic pressure supplied to the exhaust side hydraulic controller 36 is controlled.

  An intake valve 42 is connected to the intake camshaft 31 via a rocker arm 41, and an exhaust valve 44 is connected to the exhaust camshaft 34 via a rocker arm 43. The intake valve 42 is opened / closed by the intake-side hydraulic controller 33, and the exhaust valve 44 is opened / closed by the exhaust-side hydraulic controller 36. At the same time, the output (kW) and torque (N · m) of the engine 1 are adjusted.

  For example, if the valve closing timing when closing the intake valve 42 is retarded beyond the bottom dead center (BDC) of the piston 2, the intake valve 42 is compressed when the air-fuel mixture is compressed in the compression stroke of the engine 1. Since the volume ratio of the combustion chamber after closing is reduced, the compression ratio can be reduced. Further, if VVT 3 advances the retarded opening / closing timing, the reduced compression ratio can be increased.

  The crankshaft 4 is rotatably supported by the engine block 6 via a crank journal 11 and is connected to the piston 2 via a connecting rod so that the reciprocating motion of the piston 2 is transmitted to rotate. It has become.

  The oil supply control device 5 includes an oil pan 51, an oil strainer 52, a pump mechanism 53, an oil filter 54 for filtering oil discharged from the pump mechanism 53, an oil passage portion 55, an oil recirculation portion 56, An oil switch valve (OSV) 57, an oil injection nozzle 58, a stop valve 59 (see FIG. 2) for adjusting the flow rate of oil flowing through the pump mechanism 53, and an electronic control unit (ECU: Electronic Control Unit). ) 60. The oil supply control device 5 is configured to supply oil to each lubrication unit 10 in the engine 1 to lubricate and cool each lubrication unit 10.

  The lubrication unit 10 is a component that requires lubrication in the engine 1. For example, as illustrated in FIG. 2, the lubrication unit 10 includes a piston 2, a crank journal 11 that rotatably supports the crankshaft 4, and a connecting rod 12. The crank pin 13 connected to the crankshaft 4, the intake camshaft 31, the exhaust camshaft 34, rocker arms 41 and 43, the intake camshaft journal 47, and the exhaust camshaft journal 48 are configured.

  The oil pan 51 includes a case for storing oil recirculated from each lubrication element of the lubrication unit 10, and is fixed to the lower part of the engine block 6. In the oil stored in the oil pan 51, the suction port of the oil strainer 52 is immersed, and the oil is sucked from the suction port.

  As shown in FIG. 3, the pump mechanism 53 includes a pump main body 53h, a suction pipe 53k that distributes the oil sucked from the oil strainer 52 to the pump main body 53h, and oil discharged from the pump main body 53h to the oil filter 54. A discharge pipe 53t to be circulated is included.

  As shown in FIG. 1, the pump body 53h is composed of a pump that sucks and discharges oil, such as a trochoid pump and a gear pump, and is connected to the crankshaft 4 via a chain (not shown). A separate shaft is driven at a constant speed by the crankshaft 4. The pump main body 53h may be of a structure directly connected to the crankshaft 4 and driven at a constant speed by the crankshaft 4 regardless of the chain.

  The oil passage portion 55 includes a plurality of oil passages 55t that supply the oil purified by the oil filter 54 to the lubricating elements of the lubricating portion 10. The oil passage 55t is formed in the oil pipe 55p for pumping oil to the lubricating element of the lubricating portion 10, the one formed in the wall portion of the engine block 6 such as the main oil gallery 55m, the intake camshaft 31 and the like. It is configured to include an oil shower pipe 55 s that discharges oil toward the exhaust camshaft 34.

  The oil passage 55t is configured by an internal space through which oil dropped from the oil pipe 55p passes, and the oil passage 55t is configured by a surface of the wall portion so as to transmit the surface of the wall portion of the engine block 6. It is comprised by the medium to distribute | circulate.

  The oil recirculation part 56 includes an oil recirculation pipe 56p having an oil recirculation path 56k that branches off from an oil passage 55t that communicates the discharge port 54h of the oil filter 54 and the main oil gallery 55m and that communicates with the suction port of the pump mechanism 53. It consists of An OSV 57 that opens and closes the oil return passage 56k is provided in the oil return passage 56k. The OSV 57 is mounted on the engine block 6 and its opening / closing is controlled by the ECU 60. The OSV 57 may be mounted on a device other than the engine block 6. For example, the OSV 57 may be mounted on the pump mechanism 53.

  The OSV 57 is composed of an on-off valve having a function of opening and closing the oil recirculation passage 56k, and includes, for example, a solenoid valve that operates by electromagnetic force.

  As shown in FIGS. 1 and 4, the oil injection nozzle 58 is composed of a pipe having an oil passage 55 t inside, and the base end portion is supported by the engine block 6 so that the tip end portion faces the direction of the piston 2. . An oil injection port is formed at the tip, and oil supplied from the main oil gallery 55m to the oil passage 55t is injected from the oil injection port in the direction of the piston 2.

The ECU 60 includes a fuel supply control unit, an engine load determination unit, and an oil supply control unit, and the operation of each unit is continuously executed by a single or a plurality of programs. .
Specifically, the ECU 60 includes a CPU (Central Processing Unit), a fuel supply control unit, an engine load determination unit, a ROM (Read Only Memory) in which programs for executing operations of the oil supply control unit, and the like are temporarily stored. RAM (Random Access Memory) that stores data automatically, EEPROM (Electronically Erasable and Programmable Read Only Memory) consisting of a rewritable nonvolatile memory that operates using a battery as a power source, an input interface such as an A / D converter and a buffer An output interface circuit such as a circuit and a drive circuit is included.

  Sensors such as an air flow meter, a crank position sensor, a pressure sensor, an accelerator position sensor, a throttle opening sensor, a water temperature sensor, an oil temperature sensor, and a fuel pressure sensor are connected to the input interface circuit of the ECU 60, respectively. The output information is taken into the ECU 60 through the input interface circuit.

  In the ECU 60, the engine rotational speed Ne (rpm) is obtained based on information input from a sensor that detects the rotational speed (rpm) of the crankshaft 4 such as a crank position sensor. The opening / closing timings of the intake valve 42 and the exhaust valve 44 of the VVT 3 mounted on the engine 1 are controlled based on information on the output of the engine 1 such as a throttle opening sensor, an air flow meter, an accelerator position sensor, and a crank position sensor. It has become so.

  The air flow meter is composed of, for example, a hot wire type air flow meter, and is composed of a known one including a bridge circuit with a resistance for measuring the intake air temperature and a heating resistance, and when the intake air amount changes, the bridge A circuit may be used that feedback-controls the power supplied to the heating resistor so that the temperature difference between the resistance for measuring the intake air temperature and the heating resistor is always kept constant. The supplied power is converted into a voltage and output to the ECU 60 as an intake air amount. The ECU 60 calculates the intake air amount from a preset relationship between the voltage of the air flow meter and the flow rate of the intake air. It is configured as follows.

  This air flow meter is attached to the intake pipe so that the resistance for measuring the intake air temperature and the heating resistance are exposed in the intake passage. A bypass passage pipe for measuring the amount of intake air is provided in the intake pipe, and the bypass passage pipe is attached so that the resistance and heating resistance for measuring the intake air temperature are exposed in the intake passage of the bypass passage pipe. It may be less affected by pulsation.

  The air flow meter may be another measuring means. For example, a D-Jetronic type that detects the negative pressure in the intake pipe with a pressure sensor and converts the detected pressure into the amount of intake air may occur, and if an obstacle is placed in the flow of intake air, a vortex will occur behind it, A Karman vortex airflow meter that utilizes the phenomenon that the number of vortices increases as the flow of intake air increases. Alternatively, a plate may be provided in the intake pipe, and a movable plate type air flow meter that calculates the amount of intake air from the amount of displacement that the intake air pushes against the plate may be used.

  The crank position sensor is composed of a known sensor including, for example, a timing rotor fixed to the crankshaft 4 and an electromagnetic pickup sensor, and is fixed to the engine block 6. The crank position sensor detects the rotation of the crank such as the crank position and the crank angular velocity, and the detected rotation signal is output to the ECU 60.

  The pressure sensor is composed of a known sensor including a semiconductor piezoresistor having high sensitivity, for example. The semiconductor piezoresistor is connected to the ECU 60, detects a resistance value corresponding to the pressure in the oil passage 55, and inputs a voltage signal to the input interface circuit of the ECU 60. This oil pressure sensor is provided in the oil passage 55t on the upstream side of the VVT 3, and detects the pressure (kPa) of oil supplied to the intake side hydraulic controller 33 and the exhaust side hydraulic controller 36.

  The fuel supply control unit of the ECU 60 performs control of the injection amount of fuel injected from the fuel injection nozzle of the fuel injection device, advance angle control or delay angle control of the injection timing, and fuel corresponding to the operating state of the engine 1. It is comprised so that cut control may be performed.

  In the case of injection timing control, specifically, the fuel injection start timing and injection end timing are retarded or advanced based on a predetermined crank angle obtained from the detection information of the crank position sensor, and air-fuel ratio control is performed. The improvement in performance and the reduction of emissions in exhaust gas are promoted, and the optimum torque and output of the engine 1 are obtained.

  Further, in the case of fuel cut control, when the operating state of the engine 1 is decelerating or at high speed, the fuel injection signal to the fuel injection nozzle of the fuel injection device is stopped to stop the fuel injection. The fuel consumption in the operation state at the time of deceleration or high rotation is reduced.

  In the driving state at the time of deceleration, when the fuel cut control start condition is satisfied, for example, the accelerator pedal is not operated and the engine speed (rpm) is equal to or higher than a preset set cut speed (rpm). When it is determined that there is no need for fuel injection and the fuel cut is possible, fuel cut control is executed by the fuel supply control unit. The set cut rotation speed may be single or plural. For example, the set cut rotation speed G based on the gear shift position set based on the gear shift position of the vehicle, the set cut rotation speed F based on the load set based on the presence or absence of a load such as an air conditioner, and the coolant temperature of the engine 1 Detailed control is performed by making full use of three different set cut rotation speeds set appropriately based on the driving state of the vehicle, such as the set cut rotation speed R based on the cooling water temperature set based on May be.

  Also, the fuel cut control start condition is appropriately set based on the vehicle type such as cold region specification and warm region specification, the characteristics of the vehicle such as the type of fuel, the type of engine 1 and the displacement, and the acquired actual machine evaluation data. You may make it set. For example, the fuel cut control may be executed when the fuel cut control start condition other than the engine rotation speed (rpm) described above is satisfied. Specifically, when the vehicle speed (km / h), the intake air amount (g / rev) of the air flow meter, the fuel pressure (kPa), and the throttle opening (%) are satisfied, the fuel cut control is performed. You may make it perform.

  In the operating state at the time of high rotation, for example, the engine 1 exceeds the maximum rotation speed range, that is, the maximum allowable normal rotation speed NeG of the engine 1 corresponding to each vehicle speed, and the maximum allowable rotation such as the fuel cut rotation speed for preventing over-rev. When the region is less than a few NeC, fuel cut control is executed, the increase in the rotational speed of the engine 1 is suppressed, and damage to the engine 1 is prevented. Specifically, the fuel cut control is executed when the set cut rotation speed (rpm) is set to 8,000 rpm and the engine 1 exceeds 8,000 rpm.

The fuel cut control is performed when the engine 1 becomes lower than the return rotational speed (rpm), or when the driver requests the acceleration to open the throttle when the accelerator pedal is operated. It will be executed until the need arises.
This return rotational speed is a rotational speed at which fuel injection is restarted when the coasting traveling with the drive of the engine 1 stopped is stopped. For example, the rotational speed is set to a rotational speed that is lower than the set cut rotational speed by a fixed rotational speed. Has been.

  The engine load determination unit of the ECU 60 is the immediately preceding engine load immediately before the fuel cut control of the engine 1 obtained by the fuel supply control unit based on the engine load information immediately before the fuel cut control of the engine 1 is executed. The reference engine load that is set in advance and serves as a reference for the level of the engine load, that is, a threshold value as the reference load is compared. By this comparison, it is determined whether or not the immediately preceding engine load is higher than the reference engine load.

  The engine load information includes, for example, an output signal of an intake air amount (g / rev) of an air flow meter, an output signal of an intake air pressure (kPa) and an oil pressure (kPa) of a pressure sensor, and an accelerator opening ACC of an accelerator position sensor. Output signal, throttle opening output signal of the throttle opening sensor, crank rotation output signal of the crank position sensor, cooling water temperature (° C) output signal of the water temperature sensor, lubricating oil temperature (° C) output signal of the oil temperature sensor Information including each output signal such as an output signal of fuel pressure (kPa) of the fuel pressure sensor is included.

The ECU 60 calculates a specific immediately preceding engine load based on the arbitrarily selected engine load information. The engine load information arbitrarily selected from these may be single or plural.
The engine load information can be temporarily stored in a RAM that predicts the engine load in the ECU 60, and can be read and used as necessary.

  The reference engine load corresponds to the immediately preceding engine load obtained from the aforementioned engine load information and is the same type of load as the immediately preceding engine load so that it can be directly compared. Specifically, the immediately preceding engine load and the reference engine load are Are preferably the same unit.

  The reference engine load varies depending on the vehicle type such as cold region specification and warm region specification, and the characteristics of the vehicle such as the type of fuel, the type of engine 1 and the displacement, and based on the acquired actual machine evaluation data It is set appropriately for each characteristic, and may be a numerical value serving as a determination criterion, or may be a map serving as a determination criterion such as an engine load map corresponding to the operating state of the engine 1.

  With respect to this reference engine load, it is possible to determine what kind of control is prioritized in the actual machine evaluation. Specifically, priority is given to high-side hydraulic pressure control, and priority is given to improving the performance after returning from fuel cut control, for example, maintaining acceleration and eliminating slack, or controlling low-side hydraulic pressure. It is possible to determine whether priority is given to improving the fuel efficiency or which control is given priority based on the superiority of the vehicle.

  This High-side hydraulic pressure is obtained by closing the oil recirculation passage 56k so that the OSV 57 is closed and a part of the oil flowing through the oil passage 55t is not recirculated to the pump mechanism 53 via the oil recirculation passage 56k. The oil pressure on the low side is obtained by opening the OSV 57 and returning a part of the oil flowing through the oil passage 55t to the pump mechanism 53 via the oil return passage 56k.

  The oil supply control unit of the ECU 60 determines that the engine load immediately before the engine 1 obtained based on the load information of the engine 1 immediately before the fuel cut by the engine load determination unit is a set reference engine load, that is, a threshold value as a reference load. When it is determined that the oil pressure is not higher, the OSV 57 is opened, a part of the oil flowing in the oil passage 55t is returned to the pump mechanism 53 via the oil return passage 56k, and controlled by the low-side hydraulic pressure. ing. When the engine load determination unit determines that the immediately preceding engine load is higher than the threshold value, the OSV 57 is closed and a part of the oil flowing in the oil passage 55t is transferred to the pump mechanism 53 via the oil recirculation passage 56k. The oil recirculation passage 56k is shut off so as not to recirculate, and is controlled by the hydraulic pressure on the High side during normal traveling.

In the engine block 6, a cylinder head and a cylinder block that define a cylinder including the combustion chamber 6a and a crankcase are fastened and integrated by a fastener such as a bolt.
The engine block 6 is mounted on the vehicle body via a plurality of engine mounts (not shown).

  As shown in FIG. 1, the cooling unit 7 includes a radiator 7a that cools an inflowing high-temperature coolant with low-temperature outside air, an upper pipe 7b that causes the cooled coolant to flow into the engine block 6 from the radiator 7a, 3 includes a lower pipe 7c through which coolant flows from the engine block 6 to the radiator 7a, and a water jacket 7w shown in FIG. 3 provided in the engine block 6 so that the coolant flows in the engine block 6.

  The cooling unit 7 further includes a water pump 7p, a bypass pipe 7d interposed between the upper pipe 7b and the lower pipe 7c, and a thermostat 7t provided at a branch portion of the bypass pipe 7d and the upper pipe 7b. It is configured to include.

  The coolant in the cooling unit 7 is air-cooled in the radiator 7a, flows into the water jacket 7w in the engine block 6 from the upper pipe 7b, flows through the coolant passage in the engine block 6, and then flows from the lower pipe 7c to the radiator 7a. To reflux.

  The thermostat 7t detects the temperature of the coolant flowing into the water jacket 7w, and determines whether or not the temperature of the coolant is a set temperature, that is, the coolant circulates through the radiator 7a according to the temperature of the coolant. , To switch to one of the circulation that does not pass. For example, when the temperature of the coolant is lower than 80 ° C., the thermostat 7t switches to circulation in which the coolant does not pass through the radiator 7a. That is, the upper pipe 7b and the bypass pipe 7d communicate with each other, and the coolant flows from the lower pipe 7c into the water jacket 7w. At this time, the ECU 60 drives the water pump 7p so that the coolant circulates in the water jacket 7w, the upper pipe 7b, the bypass pipe 7d, and the lower pipe 7c so that the warm-up operation when the engine 1 is cold is promoted. ing.

  On the other hand, when the temperature of the coolant is 80 ° C. or higher, the thermostat 7t switches the coolant to circulation through the radiator 7a. At this time, the upper pipe 7b communicates with the radiator 7a, and the coolant does not pass through the bypass pipe 7d, that is, the coolant passes through the radiator 7a. The coolant is cooled by the radiator 7a, and the upper pipe 7b. From the lower pipe 7c to the radiator 7a so that the engine 1 is suitably cooled.

  The fuel injection device includes an injector provided in the engine block 6 so as to expose the fuel injection nozzle in the cylinder, a fuel tank for storing fuel, a fuel filter for purifying the fuel, and a fuel injection nozzle for fuel in the fuel tank. And a fuel pipe for circulating the fuel. In the fuel injection device, high-pressure fuel is injected into the combustion chamber 6a and uniformly mixed with the intake air sucked into the combustion chamber so as to explode efficiently. Further, the fuel injection device is configured to execute advance or retard of fuel cut or fuel injection timing according to a command of a fuel supply control unit of the ECU 60 according to the operating state of the engine 1.

  Next, the operation of oil supply control of the oil supply control device 5 according to this embodiment will be described.

FIG. 5 is a flowchart showing the operation of oil supply control of the oil supply control device.
The flowchart shown in FIG. 5 shows the execution contents of the oil supply control program stored in the ROM of the ECU 60. This oil supply control program includes the fuel supply control unit, the engine load determination unit, and the oil supply control unit. It is configured to include a single program or a plurality of programs for executing each function content. This oil supply control program is executed by the CPU of the ECU 60.

  First, when the ECU 60 detects that the starter switch that operates the starter motor of the engine 1 is turned on, or when it is less than a predetermined time after the starter switch is switched from on to off, the ECU 60 Then, at a predetermined time interval, it is determined whether or not the engine 1 satisfies the fuel cut start condition. If the fuel cut start condition is satisfied, it is determined that the fuel cut is started (step S11).

The fuel cut start condition is, for example, that the accelerator pedal is not operated, the engine speed is A (rpm) or more, and the intake air amount of the air flow meter is the intake air amount setting range B _{0 to} B ₁ (g / Rev) and the like. Specifically, the engine rotation speed A and the intake air amount setting range B _{0 to} B ₁ are owned by vehicles such as cold district specifications, warm district specifications, etc., fuel types, engine 1 types, displacement amounts, etc. It is selected as appropriate based on the characteristics of the system and the acquired actual machine evaluation data.

  When it is determined that the fuel cut is started, the ECU 60 acquires load information of the engine 1 immediately before the fuel cut (step S12). The load information of the engine 1 immediately before the fuel cut includes, for example, the engine load immediately before the fuel cut that is predicted by the ECU 60 and stored in the RAM or the like based on the intake air amount (g / rev) of the air flow meter. Has been.

  Next, the ECU 60 reads out the reference engine load, which is the reference of the engine load stored in the ROM, that is, the threshold value as the reference load, from the ROM, and immediately before the engine load obtained from the load information of the engine 1 immediately before the fuel cut. Compare with By this comparison, it is determined whether or not the immediately preceding engine load is higher than the reference engine load (step S13).

  When the ECU 60 determines that the immediately preceding engine load is higher than the reference engine load, the ECU 60 closes the OSV 57 and recirculates the oil so that a part of the oil flowing in the oil passage 55t does not recirculate to the pump mechanism 53 via the oil recirculation passage 56k. The passage 56k is shut off, and control is performed with the high hydraulic pressure during normal travel (step S14).

  When the ECU 60 determines that the immediately preceding engine load is not higher than the reference engine load, the ECU 60 opens the OSV 57 and returns a part of the oil flowing in the oil passage 55t to the pump mechanism 53 via the oil return passage 56k. Control is performed by the hydraulic pressure on the side (step S15).

Further, the ECU 60 determines whether or not the execution of the fuel cut control is finished after executing the control of step S14 or step S15 (step S16).
For example, the ECU 60 terminates execution of the fuel cut control and becomes lower than a return rotational speed (rpm) for returning the engine 1 to a normal fuel supply state, or the driver operates the accelerator pedal. It is determined that the fuel cut control has been completed when fuel injection is required, such as when an acceleration request is made to open the throttle.

  When the ECU 60 determines that the fuel cut control has been completed, the hydraulic control during normal driving, that is, the OSV 57 is closed, and a part of the oil flowing in the oil passage 55t is pumped through the oil return passage 56k. The oil recirculation passage 56k is blocked so as not to recirculate to the mechanism 53, and the control is returned to the high-side hydraulic control during normal traveling (step S17).

Next, the ECU 60 determines, for example, whether or not the engine 1 has stopped based on the output signal of the crank position sensor, and when determining that the engine 1 has stopped, the oil supply control device 5 according to the present embodiment. The oil supply control is terminated (step S18).
When it is determined in step S11 that the fuel cut of the engine 1 has not started, the ECU 60 shifts the process to step S18 and determines whether or not the engine 1 has stopped.
When it is determined that the engine 1 is not stopped, the ECU 60 returns to step S11 for determining whether or not the fuel cut of the engine 1 has started.

  Since the oil supply control device 5 according to the present embodiment is configured as described above, the following effects can be obtained.

  The oil supply control device 5 according to the present embodiment includes an oil pan 51, a pump mechanism 53 that supplies oil to the lubrication unit 10 of the engine 1 via an oil passage 55t, an oil recirculation unit 56, an OSV 57, and a fuel for the ECU 60. When the engine load determination unit of the ECU 60 determines that the load of the engine 1 is higher than the threshold value, the OSV 57 is closed by the oil supply control unit of the ECU 60. When the engine load determination unit of the ECU 60 determines that the load of the engine 1 is lower than the threshold value, the OSV 57 is opened by the oil supply control unit of the ECU 60 and is controlled with the low side hydraulic pressure. It is composed of things.

  As a result, when fuel cut is started by the fuel supply control unit of the ECU 60, the engine load determination unit of the ECU 60 compares the load of the engine 1 immediately before the fuel cut with a threshold value, and determines its level.

  If it is determined that the load on the engine 1 is higher than the threshold value, the oil supply control unit of the ECU 60 closes the OSV 57 and controls it with the high hydraulic pressure. It is not controlled by the oil pressure on the Low side. Even during the fuel cut control of the engine 1, when the load on the engine 1 is relatively large, it is controlled by the hydraulic pressure on the high side, and the oil pressure required for the oil jet that injects the oil toward the piston can be secured. The problem that the cooling capacity of the piston by the oil jet is reduced during the cut control is solved. Further, the amount of oil supplied to the lubrication part of the engine 1 is reduced, and the problem that sufficient lubrication and cooling are not performed is solved.

  FIG. 6 is a graph showing the oil pressure in the oil passage with respect to the engine speed Ne of the oil supply control device according to the present embodiment.

Further, when the load of the engine 1 is relatively small during the fuel cut control, as shown in FIG. 6, since the fuel pressure control is performed until the fuel cut control is completed, the discharge amount (mm ³ / sec) is controlled. ) × pressure (kPa), the power (w) of the pump mechanism 53 decreases. That is, a part of the oil discharged from the pump mechanism 53 is returned to the pump mechanism 53 from the oil recirculation unit 56, so that the pressure (kPa) of the oil discharged from the pump mechanism 53 decreases and the pump mechanism 53 Work rate (w) decreases. In this case, since the load of the pump mechanism 53 connected to the crankshaft 4 is reduced, the friction of the crankshaft 4 is reduced, the load of the engine 1 is reduced, and the fuel consumption rate (g / KWh: g is the fuel consumption rate). Weight, KW is output, h is time), and so-called fuel efficiency is improved.

  As described above, in the oil supply control device 5 according to the present embodiment, the oil recirculation unit 56 branched from the oil passage 55t is formed, and a simple structure and simple control in which the OSV 57 is provided in the oil recirculation unit 56 are provided. Therefore, when the fuel cut control of the engine 1 is performed, fine control of the oil supply can be executed due to the load of the engine 1, and the engine can be cooled and lubricated with oil, and the fuel consumption rate can be improved. There is an effect that both can be achieved.

  Note that even if the engine 1 includes the VVT 3 that can change the opening / closing timing of at least one of the intake valve 42 and the exhaust valve 44 depending on the oil pressure, the control of the VVT 3 may be adversely affected. Absent. That is, as shown in FIG. 6, when the fuel cut control of the engine 1 is performed, when the low-side hydraulic pressure is controlled by the low-side hydraulic pressure, the low-side hydraulic pressure falls below the lower limit of the oil jet hydraulic pressure (kPa), and the oil jet injection stops. However, since the low-side hydraulic pressure is larger than the lower limit VVT control hydraulic pressure (kPa) for operating the VVT 3, there is no effect on the advance control or retard control of the VVT 3.

  Further, as shown in FIG. 6, when the ECU 60 determines in step S16 that the fuel cut control has been completed, in step S17, the engine 1 promptly performs hydraulic control during normal travel, that is, on the High side. Since the control is returned to the hydraulic pressure control, the lower limit of the oil jet hydraulic pressure (kPa) is exceeded, and the oil is injected from the oil injection nozzle 58 toward the piston 2 as shown in FIG. As a result, the piston 2 is cooled by the oil, the air-fuel mixture in the combustion chamber 6a is cooled, and the so-called knocking of the engine 1 is suppressed. Further, when the engine 1 is returned to the high-pressure hydraulic control, the advance control of the ignition timing becomes possible, and the combustion of the air-fuel mixture in the combustion chamber 6a is improved. That is, the engine torque after returning from the fuel cut can be improved.

  The pump mechanism 53 of the oil supply control device 5 according to the present embodiment is configured to be connected to the crankshaft 4 so that the pump mechanism 53 is driven by the power of the engine 1, and oil is supplied from the oil passage 55t to the pump mechanism 53. A case has been described in which the oil recirculation passage 56k for recirculating oil is formed, and when the engine 1 is subjected to fuel cut control and the engine load is relatively small, the OSV 57 provided in the oil recirculation passage 56k is opened to make the oil pressure on the Low side.

  However, the pump mechanism of the oil supply control device according to the present invention may be configured with another structure. For example, when the pump mechanism is composed of a variable displacement type oil pump and the engine 1 is fuel cut controlled and the engine load is relatively small, the capacity of the pump mechanism is reduced, the load of the pump mechanism is reduced, and the fuel consumption is reduced. You may make it improve. Further, the pump mechanism is composed of two pump mechanisms, a large capacity pump mechanism and a small capacity pump mechanism. When the engine 1 is fuel cut controlled and the engine load is relatively small, the small capacity pump mechanism It is possible to reduce the load on the pump mechanism to improve the fuel consumption.

  As described above, the oil supply control device according to the present invention can improve the fuel consumption of the engine when the fuel cut of the engine is executed, and suppress the decrease in the cooling capacity of the engine due to the oil by simple control. This is useful for an oil supply control device that can lubricate the lubrication part by supplying oil to the lubrication part of the engine.

1 is a schematic perspective view of a vehicle engine to which an oil supply control device according to an embodiment of the present invention is applied. It is a block diagram which shows each lubrication part inside an engine to which the oil supply control apparatus which concerns on embodiment of this invention is applied, and the flow of oil. It is a circuit diagram of the pump mechanism of the oil supply control apparatus which concerns on embodiment of this invention. It is a fragmentary sectional view of the cylinder block which accommodates the piston of the oil supply control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the oil supply control in the oil supply control apparatus which concerns on embodiment of this invention. It is a graph which shows the oil_pressure | hydraulic in an oil path with respect to the engine speed Ne of the oil supply control apparatus which concerns on embodiment of this invention.

Explanation of symbols

1 Engine 2 Piston 3 VVT (Variable valve timing mechanism)
DESCRIPTION OF SYMBOLS 4 Crankshaft 5 Oil supply control apparatus 6 Engine block 7 Cooling part 10 Lubrication part 51 Oil pan 52 Oil strainer 53 Pump mechanism 54 Oil filter 55 Oil passage part 55t Oil passage 56 Oil recirculation part 56k Oil recirculation passage 57 OSV (oil switch valve )
58 Oil injection nozzle 59 Stop valve 60 ECU (electronic control unit, oil supply control unit, fuel supply control unit, engine load determination unit)

Claims (1)

Oil having an oil pan for storing oil, a pump mechanism for supplying the oil stored in the oil pan to an engine lubrication unit through an oil passage, and an oil supply control unit for controlling the supply of the oil In the supply control device,
An oil recirculation unit having an oil recirculation passage branched from the oil passage and recirculating part of the oil in the oil passage to the pump mechanism;
An oil switch valve provided in the oil recirculation section to open and close the oil recirculation passage;
A fuel supply control unit that controls supply of fuel to the engine in accordance with an operating state of the engine;
An engine load determination unit that determines whether or not the load of the engine immediately before the fuel cut by the fuel supply control unit is performed is higher than a reference load;
When the engine load determination unit determines that the engine load is higher than the reference load, the oil supply control unit closes the oil switch valve, and the engine load determination unit causes the engine load to be When it is determined that the load is lower than the reference load, the oil supply control unit opens the oil switch valve and returns a part of the oil flowing in the oil passage to the pump mechanism through the oil return passage. An oil supply control device characterized in that

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