JP5786673B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly, to a control device for an internal combustion engine that reduces the rotational speed of the internal combustion engine when an abnormality in hydraulic pressure of the internal combustion engine is detected.

2. Description of the Related Art Conventionally, there is known an oil supply device for an internal combustion engine that discharges oil stored in an oil pan from an oil pump and supplies the oil to a supply site.
Normally, the oil-supplied part is a hydraulic drive part mounted on the internal combustion engine, such as a hydraulic variable valve mechanism or a hydraulic lash adjuster for the valve system, or a lubrication part of the internal combustion engine such as a crankshaft or a camshaft. It is configured to include.

  The oil discharged from the oil pump is supplied to the plurality of supplied parts through an oil supply path in the order of, for example, a hydraulic variable valve mechanism, a hydraulic lash adjuster, and a lubricating part of the internal combustion engine.

  2. Description of the Related Art Conventionally, in an internal combustion engine mounted on a vehicle, as an oil supply device that supplies oil used for lubrication and cooling of the internal combustion engine to a supply site, oil set to an oil discharge amount proportional to the rotational speed of the internal combustion engine A pump is used.

By the way, the oil stored in the oil pan is supplied to the supply site by the oil pump and then collected in the oil pan.
At this time, if the amount of oil stored in the oil pan is small, the recovery efficiency of the oil recovered in the oil pan deteriorates, and the oil level (oil level) stored in the oil pan is less than the appropriate amount. Decline, that is, lack.

  When the oil level decreases in this way, the strainer for sucking oil from the oil pan toward the oil pump may be in a state of sucking air (hereinafter, this state is referred to as air sucking).

  When the oil pump is in the air sucking state, the hydraulic pressure discharged from the oil pump decreases, so that a sufficient amount of oil and hydraulic oil cannot be supplied from the oil pump to the lubrication site. Lubricity may deteriorate and seizure of the lubricated part may occur.

  For this reason, in order to prevent the lubricity of the lubrication part from deteriorating and seizure of the lubrication part when the oil pressure abnormality is detected, the throttle valve opening is gradually reduced to reduce the rotational speed of the internal combustion engine. There is known a control device for an internal combustion engine that protects the internal combustion engine by performing the operation (see, for example, Patent Document 1).

JP 2004-124816 A

  However, such a conventional control device for an internal combustion engine is configured to limit the opening degree of the throttle valve in accordance with the hydraulic pressure, and restricts the opening degree of the throttle valve in consideration of the oil temperature. However, there are the following problems.

  When the oil temperature is high, the oil cooling performance deteriorates, and therefore it is necessary to prevent seizure of the lubrication site. For this reason, it is necessary to protect the internal combustion engine by reducing the rotational speed of the internal combustion engine at an early stage by reducing the opening of the throttle valve.

  On the other hand, when the oil is at a low temperature that can ensure cooling performance, the throttle valve opening degree is the same as when the oil temperature is high, although there is a possibility that seizure of the lubrication part may not occur. If the control is performed to reduce the rotational speed of the internal combustion engine by reducing the engine speed, the rotational speed of the internal combustion engine will rapidly decrease. Therefore, there is a possibility that the driver feels uncomfortable when the driving state changes rapidly.

  The present invention has been made in order to solve the above-described conventional problems, and can reduce the rotational speed of the internal combustion engine at high oil temperature to improve the cooling performance of the lubrication part, and can also cool the oil. It is an object of the present invention to provide a control device for an internal combustion engine that can prevent a sudden change in operating state at a low oil temperature at which performance can be ensured, thereby preventing the driver from feeling uncomfortable.

In order to achieve the above object, a control device for an internal combustion engine according to the present invention includes (1) a throttle valve that is disposed in an intake pipe and adjusts an intake air amount supplied to the internal combustion engine, and a drive that drives the throttle valve. Provided in an internal combustion engine having a member and an oil supply path for supplying oil stored in the oil storage means to a plurality of lubrication parts of the internal combustion engine and collecting the oil in the oil storage means, and flows through the oil supply path A control device for an internal combustion engine having control means for reducing the number of revolutions of the internal combustion engine by driving the drive member and detecting the opening of the throttle valve to the closed side when an abnormality in hydraulic pressure is detected, The control means opens the throttle valve more than when the oil temperature is lower than the predetermined temperature on the condition that the oil temperature is equal to or higher than the predetermined temperature when the oil pressure abnormality is detected. Run the fail-safe process of controlling the drive member so becomes the closing side, the control device of the internal combustion engine, warning that pressure is abnormal based on the abnormality signal is further outputted from the control means Warning means, and the control means executes the fail-safe process based on oil pressure and oil temperature on the condition that an abnormal signal is output to the warning means, and the control means sends the oil storage means The period from when the stored oil is supplied to the lubrication part until it is collected by the oil storage means is defined as an oil circulation period, and the oil pressure value of the oil supply path is predetermined within the oil circulation period that is temporally continuous. It integrates the time a value below the integrated value on condition that a determination value or more, and a and outputs an abnormality signal to the warning means

  This internal combustion engine control device is provided with a fail-safe system that controls the opening of the throttle valve closer to the closed side than when the oil temperature is lower than a predetermined temperature on condition that the oil temperature is equal to or higher than a predetermined temperature when an abnormality in hydraulic pressure is detected. Since the process is executed, the amount of intake air supplied to the internal combustion engine can be reduced when the oil temperature is high.

  For this reason, the limit of the throttle valve opening can be increased at a high oil temperature when the oil cooling performance is low, and the rotational speed of the internal combustion engine can be lowered at an early stage. The internal combustion engine can be protected.

On the other hand, when the oil temperature is lower than a predetermined value when an oil pressure abnormality is detected, the throttle valve opening limit is smaller than the oil temperature higher than the predetermined value, or the opening degree is not limited. Like that.
That is, when the oil temperature is low, it is an operating state in which the oil cooling performance can be ensured. Therefore, by increasing the amount of intake air supplied to the internal combustion engine as compared with the high oil temperature, the operating state is It is possible to prevent sudden changes and prevent the driver from feeling uncomfortable.
Since the control device for the internal combustion engine has warning means for warning that the hydraulic pressure is abnormal based on the abnormal signal output from the control means, the driver is informed that the amount of oil supplied to the lubrication site has decreased. It is possible to warn the driver and to prompt the driver to check the oil in the oil storage means or to replenish the oil storage means with oil. As a result, the oil level of the oil storage means can be made appropriate, and seizure of the lubrication site can be prevented.
In addition, since the control means performs fail-safe processing after outputting an abnormal signal to the warning means, the restriction of the throttle valve opening is increased at an early stage of the internal combustion engine at a high oil temperature when the oil cooling performance is low. When the rotational speed is decreased, the driver can recognize that the driving state has changed suddenly due to an abnormality in hydraulic pressure. As a result, it is possible to prevent the driver from feeling uncomfortable even when the driving state changes suddenly.
This internal combustion engine control device outputs an abnormal signal to the warning means on condition that the integrated value of the time when the hydraulic pressure value becomes equal to or less than a predetermined value within the oil circulation period becomes equal to or greater than the determination value. Even when the fluctuation cycle becomes long, it is possible to detect an abnormality in the hydraulic pressure and warn the driver.
For this reason, it is possible to reliably detect that the oil level stored in the oil storage means has decreased, or that the oil pressure in the oil supply path has decreased. As a result, it is possible to prevent seizure of the lubrication site of the internal combustion engine.

  In the control device for an internal combustion engine according to (1), (2) oil pressure detecting means for detecting the oil pressure flowing through the oil supply path, and oil temperature detecting means for detecting the oil temperature, wherein the control means includes: The hydraulic pressure information is acquired based on the detection information from the hydraulic pressure detection means, and the oil temperature information is acquired based on the detection information from the oil temperature detection means.

  In this control device for an internal combustion engine, the control means acquires the oil pressure information from the oil pressure detection means, and also acquires the oil temperature information from the oil temperature detection means. Therefore, the fail safe process is performed based on the actual values of the oil pressure and the oil temperature. Can be executed.

  According to the present invention, it is possible to improve the cooling performance of the lubrication part by reducing the rotational speed of the internal combustion engine at a high oil temperature, and at the same time, the operating state changes abruptly at a low oil temperature that can ensure the oil cooling performance. Therefore, it is possible to provide a control device for an internal combustion engine that can prevent the driver from feeling uncomfortable.

1 is a diagram showing an embodiment of a control device for an internal combustion engine according to the present invention, and is a schematic configuration diagram of an engine provided with the control device for an internal combustion engine. 1 is a diagram showing an embodiment of a control device for an internal combustion engine according to the present invention, and is a schematic perspective view of the engine. FIG. It is a figure showing one embodiment of a control device of an internal-combustion engine concerning the present invention, and is a block diagram of a control device. 1 is a diagram showing an embodiment of a control apparatus for an internal combustion engine according to the present invention, and is a block diagram showing a flow of oil and a supplied part composed of a lubricating part of an engine and a hydraulically driven part. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and is a figure which shows a fail safe determination map. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and is a figure which shows a specific temperature fail safe determination map. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and shows the relationship between the oil_pressure | hydraulic for every oil level of oil pan and time on condition of a fixed engine speed and a fixed oil temperature. FIG. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and is a flowchart of a fail safe process. FIG. 9 is a diagram showing an embodiment of a control device for an internal combustion engine according to the present invention, and is a flowchart of fail-safe processing subsequent to FIG. 8.

Embodiments of an internal combustion engine control apparatus according to the present invention will be described below with reference to the drawings.
FIGS. 1-9 is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention.
First, the configuration will be described.
In FIG. 1, a vehicle 1 includes an engine 2 as an internal combustion engine, an oil supply device 3, and a control device 4.

  The engine 2 is, for example, an in-line 4-cylinder engine that includes four cylinders and four pistons 10 each. The number of cylinders is an example, and is not limited to four cylinders. The engine 2 is not limited to a gasoline engine but may be a diesel engine.

  The engine 2 includes a cylinder block 5, a cylinder head 6 fastened to the upper part of the cylinder block 5, and an oil pan 7 fastened to the lower part of the cylinder block 5 and storing engine oil O. .

  A cylinder bore 8 constituting a cylinder is formed in the cylinder block 5, and a piston 10 is accommodated in the cylinder bore 8. A combustion chamber 9 is formed in the upper part of the cylinder bore 8, and the combustion chamber 9 is composed of a space surrounded by the cylinder bore 8, the top surface of the piston 10, and the lower surface of the cylinder head 6.

  The engine 2 is a so-called four-cycle gasoline engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while the piston 10 reciprocates in the cylinder bore 8.

  The piston 10 is connected to the crankshaft 12 via a connecting rod 11, and the reciprocating motion of the piston 10 is converted into the rotational motion of the crankshaft 12 by the connecting rod 11.

As shown in FIG. 2, the crankshaft 12 is rotatably supported by the cylinder block 5 via a crank journal 12a.
The cylinder head 6 of the engine 2 is provided with a spark plug 38, and the ignition timing of the spark plug 38 is adjusted by the igniter 13.

  An intake pipe 14 and an exhaust pipe 15 are connected to the cylinder head 6, and the intake pipe 14 and the exhaust pipe 15 communicate with the combustion chamber 9. An intake valve 16 is provided between the intake pipe 14 and the combustion chamber 9. By opening and closing the intake valve 16, the intake pipe 14 and the combustion chamber 9 are communicated and disconnected.

  Further, an exhaust valve 17 is provided between the exhaust pipe 15 and the combustion chamber 9, and the exhaust pipe 15 and the combustion chamber 9 are communicated and blocked by opening and closing the exhaust valve 17.

  As shown in FIG. 2, the opening / closing drive of the intake valve 16 and the exhaust valve 17 is performed by the respective rotations of the intake camshaft 18 and the exhaust camshaft 19 to which the rotation of the crankshaft 12 is transmitted. The intake camshaft 18 and the exhaust camshaft 19 have cam journals 18a and 19a supported on the cylinder head 6 so as to be rotatable.

  The intake camshaft 18 and the exhaust camshaft 19 are provided with a VVT (Variable Valve Timing) 20, and this VVT 20 is a mechanism for controlling the intake valve 16 and the exhaust valve 17 at the optimum opening / closing timing according to the operating state. is there.

  The VVT 20 includes VVT controllers provided at axial ends of the intake camshaft 18 and the exhaust camshaft 19, respectively. The VVT 20 is supplied with hydraulic pressure to each VVT controller, so that the intake camshaft 18 for the cam sprocket is provided. The opening / closing timing of the intake valve 16 and the exhaust valve 17 can be advanced or retarded by changing the phase of the exhaust camshaft 19.

  The hydraulic pressure supplied to each VVT controller of the VVT 20 is controlled by intake side and exhaust side oil control valves (OCV) 20a, 20b.

  As shown in FIG. 1, the intake pipe 14 is provided with an air cleaner 21 and an electronically controlled throttle valve 23 for adjusting the intake air amount of the engine 2.

  The throttle valve 23 is driven by a throttle motor 24 constituting a drive member, and the opening degree of the throttle valve 23 is detected by a throttle position sensor 25.

  The exhaust pipe 15 is provided with a three-way catalyst 26 that purifies the exhaust gas. The intake pipe 14 is provided with an injector 27 for fuel injection. Fuel of a predetermined pressure is supplied from the fuel tank to the injector 27 by a fuel pump, and the injector 27 injects fuel into the intake pipe 14.

  The fuel injected into the intake pipe 14 is mixed with intake air to be mixed into the combustion chamber 9 and introduced into the combustion chamber 9, and the mixture introduced into the combustion chamber 9 is ignited by the spark plug 38. Burn and explode.

  The combustion of the air-fuel mixture in the combustion chamber 9 and the explosion cause the piston 10 to reciprocate and the crankshaft 12 rotates.

  A signal rotor 28 having a plurality of teeth 28 a is attached to the outer peripheral surface of the crankshaft 12, and a crank position sensor 29 is disposed near the side of the signal rotor 28.

  The crank position sensor 29 is, for example, an electromagnetic pickup, and generates a pulse signal (output pulse) corresponding to the teeth 28a of the signal rotor 28 when the crankshaft 12 rotates.

  In the present embodiment, the spark plug 38, the injector 27, and the throttle motor 24 are controlled based on an output signal from an ECU (Electronic Control Unit) 41.

  As shown in FIGS. 1 and 4, the oil supply device 3 includes an oil pan 7 as oil storage means, an oil strainer 30, an oil pump 31, and engine oil discharged from the oil pump 31 (hereinafter simply referred to as “oil”). The oil filter 32 and the oil passage 33 are filtered.

  The oil supply device 3 sucks the oil stored in the oil pan 7 by the oil pump 31 and supplies it to the lubrication site of the engine 2 to lubricate and cool the lubrication site and to operate the hydraulic drive parts. Yes.

  The oil supplied to each lubrication site and the hydraulic drive parts is then dropped inside the cylinder head 6 and the cylinder block 5 and returns to the oil pan 7 again. The oil circulation in the oil supply device 3 will be specifically described.

  As shown in FIG. 4, the oil supply path 40 of the oil supply apparatus 3 includes an oil passage 33, and the oil supply path 40 is oil stored in the oil pan 7 by a plurality of pipes and passages. Is supplied to the lubrication part of the engine 2 and the hydraulic drive device, and is then recovered as a circulation path for recovery to the oil pan 7.

  That is, the oil supply path 40 is an oil circulation path from the oil stored in the oil pan 7 to the oil pan 7 after being supplied to the lubrication part and the hydraulic drive parts of the engine 2 by the oil pump 31.

  An oil strainer 30 is immersed in the oil pan 7, and the oil strainer 30 filters oil stored in the oil pan 7.

  The oil stored in the oil pan 7 is sucked up by the oil pump 31 through the oil strainer 30 and discharged from the oil pump 31 to the oil passage 33. An oil filter 32 is interposed in the oil passage 33, and the oil filter 32 removes foreign matters mixed in the oil.

  The oil pump 31 is composed of, for example, a trochoid pump or a gear pump, and is connected to the crankshaft 12 via a chain 47 (see FIG. 2), and is driven at a constant speed by the crankshaft 12 on a separate axis from the crankshaft 12. It has come to be. Note that the oil pump 31 may have a structure directly connected to the crankshaft 12 and driven at a constant speed by the crankshaft 12 without using the chain 47.

  A main gallery 34 is provided downstream of the oil passage 33, and the main gallery 34 extends in the wall surface of the cylinder block 5 along the crankshaft 12 as shown in FIG. 2.

The main gallery 34 is supplied with oil pressurized by the oil pump 31, and the oil supplied to the main gallery 34 is branched and supplied to the cylinder head 6 and the cylinder block 5. It has become.
The oil branched and supplied to the cylinder head 6 and the cylinder block 5 is supplied to the lubrication part of the engine 2 and hydraulic drive parts.

  For example, in the cylinder block 5, the supplied oil is used as lubricating oil for the crank journal 12 a, the crank pin 12 b, the connecting rod 11, etc. constituting the lubrication part. In the cylinder head 6, the cam journal 18 a constituting the lubrication part, It is used as lubricating oil such as 19a or hydraulic oil for VVT 20 constituting a hydraulic drive part.

  That is, in this embodiment, the lubrication parts of the engine 2 are the crank journal 12a, the crankpin 12b, the connecting rod 11, and the cam journals 18a and 19a. However, the lubrication site is not limited to the lubrication site, and is appropriately changed according to the configuration of the engine 2 and the like.

  As shown in FIG. 3, the control device 4 for the internal combustion engine includes the igniter 13, the throttle motor 24, the throttle position sensor 25, the injector 27, the crank position sensor 29, the accelerator opening sensor 35, the hydraulic pressure sensor 36, and the oil temperature sensor. 37, ECU 41 and warning lamp 51 are included.

  The accelerator opening sensor 35 detects the amount of depression of the accelerator pedal 35a (accelerator operation amount), and outputs a voltage signal corresponding to the accelerator opening to the ECU 41.

  The oil pressure sensor 36 constitutes oil pressure detecting means, and is provided on the oil passage 33. The oil pressure sensor 36 detects the oil pressure of the oil flowing through the oil passage 33 and outputs a signal corresponding to the oil pressure to the ECU 41 as oil pressure information. Note that the hydraulic sensor 36 may be provided in the main gallery 34.

  The crank position sensor 29 detects the rotation speed (rpm) of the engine 2 based on the rotation angle of the crankshaft 12. The crank position sensor 29 is connected to the ECU 41, and outputs a signal corresponding to the detected engine speed (rpm) to the ECU 41.

The oil temperature sensor 37 constitutes an oil temperature detecting means, is provided on the oil passage 33, and is electrically connected to the ECU 41.
The oil temperature sensor 37 is constituted by, for example, a thermistor whose resistance value changes according to the temperature, and outputs a voltage that changes according to the change of the resistance value to the ECU 41 as oil temperature information.

  The ECU 41 acquires hydraulic pressure information and oil temperature information based on detection information from the hydraulic pressure sensor 36 and the oil temperature sensor 37. The oil temperature sensor 37 may be provided in the main gallery 34 or the oil pan 7.

The ECU 41 includes a CPU (Central Processing Unit) 42, a ROM 43 (Read Only Memory) 43, a RAM 44 (Random Access Memory) 44, an input interface 45, an output interface 46, and the like.
The ROM 43 stores various control programs including a fail-safe program, a map referred to when executing these various control programs, and the like.

  The ROM 43 stores an oil circulation period determination map as a control map. In this oil circulation period determination map, the period from when the oil stored in the oil pan 7 is supplied to the lubrication device and hydraulic drive parts of the engine 2 by the oil pump 31 until the oil pan 7 is recovered is defined as the oil circulation period. This oil circulation period is stored in association with a plurality of oil temperatures. That is, the oil circulation period has a different length for each of a plurality of oil temperatures.

  In the oil circulation period determination map, determination values corresponding to the respective oil circulation periods are stored. This determination value is set to a certain ratio of length (time) corresponding to the length of the oil circulation period within the range of the length of the oil circulation period. That is, the determination value is set longer when the oil circulation period is longer than when the oil circulation period is short.

The ECU 41 performs fail-safe processing based on the throttle position sensor 25, the crank position sensor 29, the hydraulic pressure sensor 36, and the oil temperature sensor 37.
That is, the ECU 41 reads the oil circulation period and the determination value corresponding to the oil temperature of the oil from the oil circulation determination map based on the detection information from the oil temperature sensor 37. The ECU 41 continues the oil circulation period in time during the operation of the engine 2, acquires the hydraulic value discharged from the oil pump 31 based on the detection information from the hydraulic sensor 36, and oils within each oil circulation period. The time when the hydraulic pressure value of the pump 31 becomes equal to or less than the predetermined value is integrated, and the integrated value is stored in the integrating counter of the RAM 44.

  Then, the ECU 41 determines that an abnormality of the hydraulic pressure has occurred and warns that the accumulated value of the time during which the hydraulic pressure value has become equal to or less than a predetermined value in each oil circulation period has become equal to or greater than the determination value. An abnormal signal is transmitted to the lamp 51.

  In addition, the ECU 41 measures the time during which the oil circulation period and the pressure value are less than or equal to a predetermined value by a timer.

  The warning lamp 51 is connected to the ECU 41. The warning lamp 51 is a warning lamp that warns that an oil pressure abnormality has occurred and the oil level in the oil pan 7 has decreased, or that the oil pressure in the oil supply path 40 has decreased.

  The warning lamp 51 is turned on or blinks when an abnormality signal is input from the ECU 41 to warn of an abnormality in the oil pressure, so that the oil level in the oil pan 7 has decreased or the oil pressure in the oil supply path 40 has decreased. The driver is warned that In the present embodiment, the warning lamp 51 constitutes a warning means.

  On the other hand, the ROM 43 stores a fail-safe determination map shown in FIG. In the fail-safe determination map, the engine speed for suppressing the increase with respect to the hydraulic pressure and the oil temperature is associated.

  Specifically, in the fail-safe determination map, when the oil temperature (C °) of the oil is equal to or higher than Ta, an upper limit value of the engine speed (rpm) is assigned according to the oil pressure (Kp). When the oil temperature is lower than Ta, the upper limit value of the engine speed is not set regardless of the hydraulic pressure.

  The ECU 41 refers to the fail-safe determination map based on detection information from the pressure sensor 36, the oil temperature sensor 37, and the crank position sensor 29 when an abnormality in the oil pressure flowing through the oil supply path 40 is detected.

  Then, when the oil temperature is equal to or higher than Ta, the ECU 41 controls the throttle motor 24 so that the opening degree of the throttle valve 23 with respect to the depression amount of the accelerator pedal 35a than when the oil temperature is lower than Ta. Is controlled to the closed side.

  That is, the opening degree of the throttle valve 23 is controlled to be closer to the closing side than the normal opening degree of the throttle valve 23 corresponding to the depression amount of the accelerator pedal 35a, so that the restriction on the opening degree of the throttle valve 23 is increased. At this time, the ECU 41 prohibits the opening of the throttle valve 23 from closing beyond the set opening based on the detection information from the throttle position sensor 25.

When the opening of the throttle valve 23 is thus reduced, the amount of air taken into the combustion chamber 9 is reduced, and the engine speed is reduced.
When the oil temperature is lower than the predetermined temperature Ta, the opening degree of the throttle valve 23 is controlled to an opening degree corresponding to the depression amount of the accelerator pedal 35a. In the present embodiment, the ECU 41 constitutes a control means.

FIG. 6 is a specific temperature fail-safe determination map showing a fail-safe line with respect to oil pressure and engine speed when the oil temperature is equal to or higher than Ta.
In the specific temperature fail-safe determination map shown in FIG. 6, for example, a fail-safe line Li is set for the oil pressure and the engine speed when the oil temperature is 80 ° C. or higher. In addition, this oil temperature is an illustration and is not limited to this. The fail safe line Li is also a lighting line for lighting the warning lamp 51 corresponding to the hydraulic pressure.

  The ECU 41 refers to the specific fail-safe determination map shown in FIG. 6 when the oil temperature is equal to or higher than Ta, and the throttle valve 23 is connected to the accelerator pedal 35a at the oil pressure and the engine speed in the region below the fail-safe line Li. The throttle motor 24 is driven so that the opening degree corresponds to the opening degree.

  In addition, the ECU 41 drives the throttle motor 24 so that the throttle valve 23 is on the closed side with respect to the depression amount of the accelerator pedal 35a in the hydraulic pressure and engine speed range above the fail safe line Li. In addition, the engine speed shown in FIG. 6 is an example, and is not limited to this.

Next, the fail safe process executed by the ECU 41 of the control device 4 will be described with reference to FIGS.
FIG. 7 is a diagram showing the relationship between the oil pressure and the time for each oil level of the oil pan 7 under the conditions of a constant engine speed and a constant oil temperature.

  As shown in FIG. 7, when the oil level L0 of the oil pan 7 is appropriate, as shown by the hydraulic pressure characteristic A, the fluctuation of the hydraulic pressure is small and the characteristic is flat.

  In addition, when the oil level is lowered from the proper oil level L0 to the oil level L1, the oil pump 31 bites bubbles contained in the air sucked by the oil strainer 30, so-called air biting occurs, and the pressure is increased. Variation will occur. At this time, as shown by the hydraulic pressure characteristic B, the fluctuation of the hydraulic pressure becomes large, and the hydraulic pressure changes in a short cycle.

  Further, when the oil level of the oil pan 7 is lowered from the oil level L1 to the oil level L2, more air suction of the oil pump 31 is generated, and the fluctuation of the hydraulic pressure is further increased as shown by the hydraulic pressure characteristic C. The characteristic varies with a long period.

  Here, as shown in FIG. 7, the oil circulation period CT is continuous in time, and when the oil circulation period CT located in the center of FIG. 7 is viewed, the oil level of the oil pan 7 is the oil level. When it is at L2, the fluctuation cycle of the hydraulic pressure becomes longer until the oil circulation period CT.

  For this reason, the ECU 41 according to the present embodiment integrates the time (for example, indicated by Tk in FIG. 7) when the hydraulic pressure value is equal to or less than a predetermined value within each temporally continuous oil circulation period CT. Is determined to be equal to or greater than the determination value, it is determined that the oil level in the oil pan 7 has decreased, an abnormal signal is output to the warning lamp 51, and a warning is issued by the warning lamp 51.

  In the present embodiment, the oil pans 7 are added on the condition that the time when the hydraulic pressure value is less than or equal to a predetermined value is integrated within each oil circulation period CT that is temporally continuous, and that the integrated value becomes greater than or equal to the determination value. The reason why it is judged that the oil level has decreased is as follows.

  When the oil pressure fluctuation discharged from the oil pump 31 to the oil supply path 40 is repeated a predetermined number of times within a certain time, that is, when a warning is issued based on the number of oil pressure fluctuations, the pressure fluctuation period within a certain time becomes longer. , Can not issue a warning.

  For example, when the pressure fluctuation period extends to the oil circulation period from when the oil stored in the oil pan 7 is supplied to the lubrication part and the hydraulic drive parts by the oil pump 31 until the oil pan 7 collects the oil, The hydraulic pressure fluctuation occurs only once within a fixed time.

  For this reason, when the pressure fluctuation cycle is long, it is determined that the oil pressure is normal, and a warning is given by accurately determining that the oil level has decreased or that the oil pressure in the oil supply path 40 has decreased. I can't.

  Therefore, in the present embodiment, in the oil pan 7 on condition that the integrated value of the time when the hydraulic pressure value becomes equal to or less than a predetermined value within each oil circulation period CT that is temporally continuous becomes equal to or more than the determination value. It is judged that the oil level has decreased.

  In addition, as shown in FIG. 7, in order to detect oil discharge fluctuations such that the proper oil level L0 or the oil levels L1 and L2 at which the oil level is reduced is detected, the engine speed and the oil temperature are constant. It is desirable that

  Since the oil pressure (discharge amount) of the oil pump 31 changes according to the engine speed, when the change in the engine speed per unit time is large, such as when the vehicle 1 is accelerated or decelerated, the oil pressure varies. Becomes larger.

  For this reason, the ECU 41 executes a process of integrating the count values in order to prevent erroneous determination that the hydraulic pressure has decreased despite the normal hydraulic pressure when the fluctuation of the engine speed is large. do not do.

  Hereinafter, fail-safe processing will be described with reference to FIGS. 8 and 9 are flowcharts of fail-safe processing executed by the ECU 41, and the CPU 42 executes a fail-safe program stored in the ROM 43. The time interval at which the same steps in this flowchart are executed is constant.

In FIG. 8, when the engine is started, the CPU 42 of the ECU 41 resets the integration counter of the RAM 44 (step S1).
Next, the CPU 42 stores the oil temperature To input from the oil temperature sensor 37 in the RAM 44, and determines whether or not the oil temperature Ti has been exceeded (step S2). The oil temperature Ti is set to a low oil temperature at the cold start.

  If the CPU 42 determines that the oil temperature To is equal to or lower than the oil temperature Ti, the CPU 42 returns to step S1 and does not execute the process of integrating the count values. That is, the ECU 41 does not make a hydraulic pressure abnormality determination.

  When the ECU 41 determines that the oil temperature To exceeds the oil temperature Ti, the ECU 41 refers to the oil circulation period determination map stored in the ROM 43 based on the oil temperature To input from the oil temperature sensor 37. Then, the oil circulation period CT and the judgment value JT associated with the oil temperature To are read and set in the storage area of the RAM 44 (step S3).

  Next, the CPU 42 reads the engine speed N based on the detection information of the crank position sensor 29, and sets the engine speed N as an initial engine speed Ne0 in the storage area of the RAM 44 (step S4). The hydraulic pressure P0 is read based on the detection information of the hydraulic sensor 36, and the hydraulic pressure P0 is set as an initial value in the storage area of the RAM 44 (step S5).

  Next, the CPU 42 reads the engine speed N based on the detection information of the crank position sensor 29 (step S6), and sets the engine speed N as the latest engine speed Ne1 to the engine speed set in the storage area of the RAM 44. It is determined whether or not the rotational speed difference Ne between Ne0 and the engine rotational speed Ne1, that is, the rotational speed difference Ne per unit time of the engine 2 is, for example, 50 rpm or more (step S7). In addition, this rotation speed difference 50rpm is an illustration, Comprising: It is not limited to this.

  When the CPU 42 determines that the difference Ne between the engine speed Ne0 and the engine speed Ne1 is 50 rpm or more, the CPU 1 is accelerated and the vehicle 1 is accelerated, or the engine speed is It is determined that the vehicle 1 has been decelerated and decelerated, and the process proceeds to step S1 to reset the integration counter in the RAM 44.

  That is, since the oil pump 31 is driven by the engine 2, the hydraulic pressure increases when the engine speed increases, and the hydraulic pressure decreases when the engine speed decreases, resulting in a large pressure fluctuation of the hydraulic pressure. In particular, the pressure fluctuation time within the oil circulation period CT may be long. For this reason, the ECU 41 may erroneously determine that the oil level has decreased even though the hydraulic pressure is normal.

  Therefore, when the rotational speed difference Ne between the engine rotational speed Ne0 and the engine rotational speed Ne1 is large, the process of integrating the count values is not executed. In other words, the ECU 41 does not perform an oil level abnormality determination.

  When the CPU 42 determines that the difference Ne between the engine speed Ne0 and the engine speed Ne1 is less than 50 rpm, the CPU 42 reads the latest oil pressure P1 based on the detection information from the oil temperature sensor 37 (step). S8).

  Next, the CPU 42 compares the hydraulic pressure P0 set in the RAM 44 with the latest hydraulic pressure P1. If the hydraulic pressure P1 is larger than the hydraulic pressure P0, the CPU 42 uses the hydraulic pressure P1 as the maximum hydraulic pressure P0 within the oil circulation period CT. Is set in the storage area of the RAM 44, and a predetermined value Ps of the hydraulic pressure is calculated based on the maximum hydraulic pressure P0 (step S9).

  The predetermined value Ps is calculated by subtracting a constant pressure value Pi from the maximum hydraulic pressure P0 within the oil circulation period CT, and is set to 20 kPa, for example. That is, the predetermined value Ps = P0−Pi is obtained.

This pressure value Pi is merely an example, and the pressure value Pi varies depending on the type of engine and the operating conditions of the vehicle 1 and may be varied depending on the engine speed and hydraulic pressure.
In the present embodiment, when the maximum hydraulic pressure P0 is, for example, 70 kPa, the predetermined value Ps is set to 50 kPa.

  Next, the CPU 42 determines whether or not the difference between P0 and P1 is equal to or less than the pressure value Pi (step S10), and determines that Pi is smaller than P0 and the difference between P0 and P1 exceeds Pi. In this case, it is determined that the oil pressure value has become equal to or less than the predetermined value Ps within the oil circulation period CT, and the time when the oil pressure value has become equal to or less than the predetermined value Ps is accumulated in the accumulation counter of the RAM 44 (step S11).

  When the CPU 42 determines that the difference between P0 and P1 is equal to or less than the pressure value Pi, the CPU 42 determines that the oil pressure value exceeds the predetermined value Ps during the oil circulation period CT and the oil pressure fluctuation is small. Then, the process proceeds to step S6.

  Next, after adding the integrated value to the integrated counter of the RAM 44 in step S11, the CPU 42 determines whether or not the integrated value of the integrated counter of the RAM 44 is equal to or greater than the determination value JT set in the storage area of the RAM 44 in step S3. (Step S12).

  If the CPU 42 determines that the integrated value of the integration counter is less than the determination value JT, the time measured by the timer from the start time of the current oil circulation period CT based on the timer is stored in the RAM 44 in step S3. It is determined whether or not it is longer than the oil circulation period CT set in the region (step S13).

  Here, since the oil viscosity varies depending on the oil temperature, the oil circulation period CT is set to have a different length depending on the oil temperature. Further, the determination value JT is set to a constant time according to the oil circulation period CT.

  If the CPU 42 determines in step S13 that the measurement time is not equal to or longer than the oil circulation period CT, the process proceeds to step S6. If the CPU 42 determines that the measurement time is equal to or longer than the oil circulation period CT, the process proceeds to step S1. Move.

  On the other hand, if the ECU 41 determines in step S12 that the integrated value of the integrated counter in the RAM 44 is greater than or equal to the determination value JT set in the storage area of the RAM 44 in step S3, an abnormality in hydraulic pressure has occurred and the oil It is determined that the level has been lowered, and an abnormal signal is output to the warning lamp 51 to turn on or blink the warning lamp 51.

  Next, the CPU 42 resets the oil temperature stored in the storage area of the RAM 44 (step S15). Next, the CPU 42 reads the oil temperature T1 based on the detection information from the oil temperature sensor 37 and sets it in the RAM 44 (step S16).

  Next, the CPU 42 determines whether or not the oil temperature T1 is equal to or higher than the oil temperature Ta (step S17). If it is determined that the oil temperature T1 is equal to or lower than the oil temperature Ta, the process proceeds to step S15. The oil temperature set in the storage area of the RAM 44 is reset.

  In step S17, when the CPU 42 determines that the oil temperature T1 is lower than the oil temperature Ta, the CPU 42 does not limit the opening of the throttle valve 23 and throttles to the opening corresponding to the depression amount of the accelerator pedal 35a. The opening degree of the valve 23 is controlled.

  On the other hand, when determining in step S17 that the oil temperature T1 is equal to or higher than Ta, the CPU 42 determines whether or not the engine speed Ne1 is equal to or higher than NeT (step S18).

  If the CPU 42 determines that the engine speed Ne1 is less than NeT, the CPU 42 proceeds to step S6. If the CPU 42 determines that the engine speed Ne1 is greater than NeT, the CPU 42 detects the hydraulic pressure P1 detected within the oil circulation period CT. Is calculated (step S19). The engine speed NeT is set to 2000 rpm, for example (see FIG. 6). However, this rotation speed is an example and is not limited to this.

  Here, the reason why the average value of the hydraulic pressure P detected within the oil circulation period CT is calculated is that there is a change in hydraulic pressure within the oil circulation period CT.

  Next, the CPU 42 refers to the specific oil temperature fail-safe determination map of FIG. 6 based on the oil pressure and the oil temperature, and controls the opening degree of the throttle valve 23 to the closed side with respect to the depression amount of the accelerator pedal 35a. The throttle motor 24 is driven, that is, the opening degree of the throttle valve 23 is limited (step S20).

  As shown in FIG. 6, when the oil temperature is Ta or higher, the CPU 42 drives the throttle motor 24 to close the throttle valve 23 even when the accelerator pedal 35a is greatly depressed in the region where the hydraulic pressure is Pa1 or lower. By controlling, the engine speed is lowered so that the amount of air taken into the combustion chamber 9 is reduced and the engine speed is less than 4000 rpm.

  Further, even if the accelerator pedal 35a is greatly depressed in a region where the hydraulic pressure is greater than or equal to Pa1 and less than Pa2, the throttle motor 24 is driven to control the throttle valve 23 to the closed side, whereby the amount of air sucked into the combustion chamber 9 is reduced. The engine speed is decreased so that the engine speed is less than 5000 rpm.

  As described above, in the present embodiment, the ECU 41 sets the opening degree of the throttle valve 23 more than when the oil temperature is lower than the predetermined temperature Ta on the condition that the oil temperature is equal to or higher than the predetermined temperature Ta when the abnormality of the hydraulic pressure is detected. By driving the throttle motor 24 so as to control to the closed side, fail-safe processing is executed, so that the amount of intake air supplied to the engine 2 can be reduced when the oil temperature is high.

  For this reason, the opening of the throttle valve 23 can be reduced at a high oil temperature when the oil cooling performance is low, so that the rotational speed of the engine 2 can be reduced at an early stage. 2 can be protected.

  On the other hand, when the oil temperature is lower than the predetermined value Ta when the hydraulic pressure abnormality is detected, the ECU 41 drives the throttle motor 24 so as not to limit the opening of the throttle valve 23, thereby depressing the accelerator pedal 35a. The throttle opening is controlled according to the amount.

  That is, when the oil temperature is low, the oil cooling performance can be ensured. Therefore, the amount of intake air supplied to the engine 2 is increased compared to that at the time of the high oil temperature, so that the rotational speed of the engine 2 rapidly decreases. It is possible to prevent the driver from feeling uncomfortable.

  Further, in the present embodiment, the ECU 41 acquires the oil pressure information in the detection information from the oil pressure sensor 36 and also acquires the oil temperature information based on the detection information from the oil temperature sensor 37. The fail safe process can be executed based on the actually measured value.

  Further, in the present embodiment, since the warning lamp 51 that warns that the hydraulic pressure is abnormal based on the abnormal signal output from the ECU 41 is provided, the amount of oil supplied to the lubrication part and the hydraulic drive parts has decreased. The driver can be warned, and the driver can be prompted to check the oil in the oil pan 7 or to replenish the oil pan 7 with oil. As a result, the oil level of the oil pan 7 can be made appropriate to prevent the lubrication site from being seized.

  In addition, since the ECU 41 executes a fail-safe process after outputting an abnormal signal to the warning lamp 51, the opening of the throttle valve 23 is reduced at the time of high oil temperature when the oil cooling performance is low, and the engine 2 is rotated early. When the number is decreased, the driver can recognize that the driving state has changed suddenly due to oil abnormality. As a result, it is possible to prevent the driver from feeling uncomfortable even when the driving state changes suddenly.

  Further, in the present embodiment, the ECU 41 sets the period from when the oil stored in the oil pan 7 is supplied to the lubrication site and the hydraulic drive parts of the engine 2 by the oil pump 31 until the oil pan 7 collects the oil. The circulation period CT is used, and the time when the hydraulic pressure value is less than or equal to the predetermined value Ps is accumulated within each time-continuous oil circulation period CT, and an abnormal signal is obtained on condition that the accumulated value becomes equal to or greater than the determination value JT. Is output.

  For this reason, even if the fluctuation cycle of the hydraulic pressure is long until the oil circulation period CT as shown by the hydraulic characteristic C in FIG. 7, an abnormality in the hydraulic pressure can be detected.

  In the present embodiment, when the oil temperature with high oil cooling performance is lower than the predetermined temperature Ta, the opening degree of the throttle valve 23 is controlled to the opening degree corresponding to the depression amount of the accelerator pedal 35a to rotate the engine. However, when the oil temperature is lower than the predetermined temperature Ta, the opening degree of the throttle valve 23 is controlled to the closed side with respect to the depression amount of the accelerator pedal 35a to reduce the engine speed. May be executed.

  In this case, the restriction on the opening degree of the throttle valve 23 may be made smaller than when the oil temperature is equal to or higher than the predetermined temperature Ta. Even in this case, since the cooling performance of the oil can be ensured at the time of low oil temperature, the rotational speed of the engine 2 is rapidly increased by increasing the amount of intake air supplied to the engine 2 as compared with that at the time of high oil temperature. Can be suppressed.

  Furthermore, although the control apparatus 4 of this Embodiment demonstrated the example applied to the internal combustion engine for vehicles, if it uses an internal combustion engine as a motive power source, it is applicable, for example, what is called a hybrid vehicle, a motorcycle, etc. The present invention can be applied not only to an internal combustion engine mounted on the vehicle but also to an internal combustion engine mounted on a vehicle other than a vehicle such as a ship or a construction machine.

  As described above, the control apparatus for an internal combustion engine according to the present invention can improve the cooling performance of the lubrication part by reducing the rotational speed of the internal combustion engine at a high oil temperature, and can ensure the oil cooling performance. It has the effect of preventing sudden changes in the operating state at oil temperature and preventing the driver from feeling uncomfortable, and lowering the rotational speed of the internal combustion engine when detecting an abnormality in the hydraulic pressure of the internal combustion engine This is useful as a control device for an internal combustion engine.

2 Engine (Internal combustion engine)
4 Control device 7 Oil pan (oil storage means)
11 Connecting rod (lubricated part)
12a Crank journal (lubrication part)
12b Crank pin (lubrication part)
14 Intake pipe 18a, 19a Cam journal (lubricated part)
23 Throttle valve 24 Throttle motor (drive means)
36 Hydraulic sensor (hydraulic detection means)
37 Oil temperature sensor (oil temperature detection means)
40 Oil supply path 41 ECU (control means)
51 Warning lamp (Warning means)

Claims (2)

A throttle valve that is disposed in the intake pipe and adjusts the amount of intake air supplied to the internal combustion engine, a drive member that drives the throttle valve, and oil that is stored in oil storage means is supplied to a plurality of lubrication parts of the internal combustion engine. Provided in an internal combustion engine having an oil supply path for supplying and recovering to the oil storage means,
Control of an internal combustion engine having control means for reducing the rotational speed of the internal combustion engine by driving the drive member and controlling the opening of the throttle valve to the closed side when an abnormality in hydraulic pressure flowing through the oil supply path is detected A device,
The control means is configured so that, when an abnormality in hydraulic pressure is detected, the opening of the throttle valve is closer to the closing side than when the oil temperature is lower than the predetermined temperature, provided that the oil temperature is equal to or higher than the predetermined temperature. Execute fail-safe processing to control the drive member ,
The control device for the internal combustion engine further includes warning means for warning that the hydraulic pressure is abnormal based on an abnormal signal output from the control means,
The control means executes the fail-safe process based on hydraulic pressure and oil temperature on the condition that an abnormal signal is output to the warning means,
The control means defines an oil circulation period as a period from when the oil stored in the oil storage means is supplied to the lubrication site to when the oil is recovered by the oil storage means, and within the oil circulation period that is temporally continuous. In which the time during which the oil pressure value in the oil supply path is equal to or less than a predetermined value is integrated, and an abnormal signal is output to the warning means on condition that the integrated value is equal to or greater than a determination value. Engine control device.   An oil pressure detecting means for detecting the oil pressure flowing through the oil supply path; and an oil temperature detecting means for detecting the oil temperature, and the control means acquires the oil pressure information based on detection information from the oil pressure detecting means. 2. The control apparatus for an internal combustion engine according to claim 1, wherein oil temperature information is acquired based on detection information from the oil temperature detection means.

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