JP2013231365A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine capable of expanding a range where normal traveling can be continued according to a normal revolution speed zone, and preventing a driver from being given a sense of discomfort.SOLUTION: An ECU sets a damage-avoidance oil-pressure determination value Pp for oil pressure failure determination to increase according to an engine speed, where the value has a magnitude of not damaging a supplied portion. When a normal revolution speed is set in a low revolution speed, the ECU sets a first oil pressure determination value Pa larger than the damage-avoidance oil-pressure determination value Pp to increase according to the engine speed in the low revolution speed zone of an engine, and sets a first upper limit revolution speed Na that restricts an increase in the engine speed. The ECU restricts the engine speed at the first upper limit revolution speed Na under the condition that an oil pressure discharged from an oil pump is less than the first oil pressure determination value Pa.

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 limits an increase in the rotational speed of the internal combustion engine when an abnormality in hydraulic pressure supplied from an oil pump to a supply site 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 supply part is a hydraulic variable valve mechanism or a hydraulic lash adjuster for a valve system, such as a hydraulic drive part mounted on an engine constituting an internal combustion engine, an engine such as a crankshaft or a camshaft. The sliding part is included.

  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 sliding part of the engine.

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

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 sliding part. There is a risk that the lubricity of the part deteriorates and seizure of the sliding part occurs.

  For this reason, when detecting an abnormality in hydraulic pressure, in order to prevent the lubricity of the sliding part from deteriorating and burning of the sliding part occurs, the opening of the throttle valve is gradually reduced to reduce the engine speed. For example, a control device for an internal combustion engine that protects the engine by reducing the speed to 1800 rpm is known (for example, see Patent Document 1).

JP 2004-124816 A

  However, in such a control device for a conventional internal combustion engine, the opening of the throttle valve is limited according to the hydraulic pressure so that the engine speed is uniformly reduced to a low speed. When a decrease in hydraulic pressure is detected by a number, acceleration cannot be performed, and the driver may feel uncomfortable.

  Specifically, in a general engine, the normal rotation speed is set to a high rotation speed range or a low rotation speed range depending on a gear ratio of the transmission, a power weight ratio, or the like. For this reason, for example, in a vehicle in which the normal rotation speed is set to a low rotation speed range, if a decrease in hydraulic pressure is detected at a low rotation speed within the normal rotation speed range, the vehicle cannot be accelerated and operated. Gives a sense of incongruity to the hand.

  In addition, in a vehicle in which the normal rotation speed is set to a high rotation speed range, the difference in rotation speed between the engine rotation speed, which is a low rotation speed when a decrease in hydraulic pressure is detected, and the normal high rotation speed area is Despite the fact that the normal rotational speed is larger than that of the vehicle using the low rotational speed range, the increase in the engine rotational speed is limited in the low rotational speed range. Therefore, the uncomfortable feeling given to the driver becomes even greater than when the normal rotation speed range is set to a low rotation speed.

  The present invention has been made to solve the above-described conventional problems, and can extend the range in which normal traveling can be continued according to the normal rotational speed range, thereby suppressing the driver from feeling uncomfortable. An object of the present invention is to provide a control device for an internal combustion engine.

  In order to achieve the above object, a control device for an internal combustion engine according to the present invention is (1) provided in an internal combustion engine having an oil pump that supplies oil stored in an oil storage means to a supply site. A control device for an internal combustion engine, comprising engine control means for limiting an increase in the rotational speed of the internal combustion engine when determining an abnormality in the hydraulic pressure supplied to the supplied part, wherein the engine control means is configured to rotate the internal combustion engine. When the damage avoidance hydraulic pressure judgment value for hydraulic pressure abnormality judgment of a magnitude that does not damage the supplied part so as to increase according to the number is set, and when the normal rotational speed is set in the low rotational speed range, A first hydraulic pressure determination value for determining a hydraulic pressure greater than the damage avoidance hydraulic pressure determination value is set so as to increase according to the rotational speed of the internal combustion engine at least in a low rotational speed range of the internal combustion engine; A first upper limit number of revolutions that limits an increase in the number of revolutions of the combustion engine is set, and the rotation of the internal combustion engine is performed on condition that the hydraulic pressure discharged from the oil pump becomes less than the first hydraulic pressure determination value. When the number is limited to the first upper limit rotational speed and the normal rotational speed is set in a high rotational speed range, the first hydraulic pressure determination value is increased so as to increase according to the rotational speed of the internal combustion engine. A second hydraulic pressure determination value for hydraulic pressure abnormality determination that is larger than the first upper limit rotational speed and a second upper limit rotational speed that is higher than the first upper limit rotational speed, and is discharged from the oil pump. On the condition that the hydraulic pressure is less than the second hydraulic pressure determination value, the rotational speed of the internal combustion engine is limited to the second upper limit rotational speed.

  The control device for the internal combustion engine increases the engine control means according to the rotational speed of the internal combustion engine at least in the low rotational speed region of the internal combustion engine when the normal rotational speed is set in the low rotational speed region. A first hydraulic pressure determination value for determining a hydraulic pressure abnormality that is larger than a damage avoidance hydraulic pressure determination value is set, and a first upper limit rotational speed that limits an increase in the rotational speed of the internal combustion engine is set, and the oil pump is discharged. On the condition that the hydraulic pressure is less than the first hydraulic pressure determination value, the rotational speed of the internal combustion engine is set to the first upper limit rotational speed.

  For this reason, for example, if the first upper limit rotational speed is set to the rotational speed corresponding to the hydraulic pressure damage avoidance determination value, the hydraulic pressure discharged from the oil pump in the lower rotational speed range than the first upper limit rotational speed is the first. Even if the hydraulic pressure determination value is less than the value, the vehicle can be accelerated by increasing the rotational speed of the internal combustion engine to the first upper limit rotational speed. For this reason, it can suppress giving a driver a sense of incongruity.

  Further, even when the hydraulic pressure is less than the first hydraulic pressure determination value, the first hydraulic pressure determination value is equal to or greater than the damage avoidance hydraulic pressure determination value. The rotational speed of the internal combustion engine can be increased to the upper limit rotational speed. For this reason, it is possible to accelerate the vehicle while avoiding the occurrence of baking or the like at the supply site.

  Further, when the engine speed is set in the high speed range, the engine control means is configured to determine a hydraulic abnormality that is larger than the first hydraulic pressure determination value so as to increase according to the rotational speed of the internal combustion engine. 2 is set, a second upper limit rotational speed is set on the higher speed range side than the first upper limit rotational speed, and the hydraulic pressure discharged from the oil pump is less than the second hydraulic pressure determination value. The engine speed of the internal combustion engine is set to the second upper limit engine speed on the condition that

  For this reason, if the second upper limit rotational speed is set to the rotational speed corresponding to the hydraulic pressure damage avoidance determination value, the hydraulic pressure discharged from the oil pump in the lower rotational speed range than the second upper limit rotational speed is the second hydraulic pressure. Even when it is less than the determination value, the vehicle can be accelerated by increasing the rotational speed of the internal combustion engine to the second upper limit rotational speed higher than the first upper limit rotational speed. Therefore, it is possible to suppress the driver from feeling uncomfortable.

  Further, since the second hydraulic pressure determination value is set on the higher hydraulic pressure side with respect to the first hydraulic pressure determination value that is higher than the damage avoidance hydraulic pressure determination value, the second hydraulic pressure determination value is equal to or higher than the rotation speed at which the supplied part is not damaged. The rotational speed of the internal combustion engine can be increased to the upper limit rotational speed. For this reason, it is possible to accelerate the vehicle while avoiding the occurrence of baking or the like at the supply site.

  In the control device for an internal combustion engine according to (1), (2) the engine control means is configured to associate a first hydraulic pressure determination value associated with the first hydraulic pressure determination value when the normal rotation speed is set in a low rotation speed range. On the condition that the first upper limit rotational speed is set to a lower hydraulic pressure side than the damage avoiding hydraulic pressure determination value at a rotational speed higher than the upper limit rotational speed of 1, and is less than the damage avoiding hydraulic pressure determination value. When the engine speed is limited to the first upper limit speed and the normal speed is set in the high speed range, the second upper limit speed associated with the second hydraulic pressure determination value is set. On the condition that the second upper limit rotational speed is set to a lower hydraulic pressure side than the damage avoidance hydraulic pressure determination value at a higher rotational speed and is less than the damage avoidance hydraulic pressure determination value, the rotational speed of the internal combustion engine is It is comprised from what restrict | limits to said 2nd upper limit rotation speed It has been.

  In this internal combustion engine control device, when the engine speed is set in the low speed range, the engine control means is configured to operate at a speed higher than the first upper limit speed associated with the first hydraulic pressure determination value. The first upper limit rotational speed is set to a lower hydraulic pressure side than the damage avoidance hydraulic pressure determination value, and the engine speed is set to the first upper limit rotational speed on condition that the lower limit is less than the damage avoidance hydraulic pressure determination value. To do.

  For this reason, when the hydraulic pressure becomes less than the damage avoidance hydraulic pressure determination value while traveling in a higher rotational speed range than the first upper limit rotational speed, the supply site is burned by limiting to the first upper limit rotational speed. Occurrence can be prevented at an early stage.

  Further, when the engine speed is set in the high speed range, the engine control means sets the second upper limit speed at a higher speed than the second upper limit speed associated with the second hydraulic pressure determination value. Is set to a lower hydraulic pressure side than the damage avoidance hydraulic pressure determination value, and the engine speed is set to the second upper limit rotation speed on condition that it is less than the damage avoidance hydraulic pressure determination value.

  For this reason, when the hydraulic pressure becomes less than the damage avoidance hydraulic pressure determination value during traveling in the rotational speed range higher than the second upper limit rotational speed, the supply site is burned by limiting to the second upper limit rotational speed. Occurrence can be prevented at an early stage.

  In the control device for an internal combustion engine according to (1) or (2), (3) the engine control means has a characteristic that an oil pressure increases as the rotational speed of the internal combustion engine increases, A hydraulic pressure level setting unit configured to set a hydraulic pressure value at a normal level and a plurality of hydraulic pressure levels at which the hydraulic pressure decreases at a constant rate with respect to the normal hydraulic pressure value; An upper limit rotational speed setting unit for setting the upper limit rotational speed or the second upper limit rotational speed, and when the normal rotational speed is set in a low rotational speed range, the damage avoiding hydraulic pressure determination value is set to the first A first specific hydraulic pressure value that matches an upper limit rotational speed of 1 is obtained, and a hydraulic pressure level that has a third specific hydraulic pressure value that matches the first specific hydraulic pressure value among the plurality of hydraulic pressure levels is determined as the first specific hydraulic pressure value. First set to the oil pressure judgment value When the pressure determination value setting unit and the normal rotation speed are set in a high rotation speed range, a second specific hydraulic pressure that matches the second upper limit rotation speed from the damage avoidance hydraulic pressure determination value values A second hydraulic pressure determination value setting that obtains a hydraulic pressure level having a fourth specific hydraulic pressure value that matches the second hydraulic pressure determination value from among the plurality of hydraulic pressure levels, and sets the second hydraulic pressure determination value as a value. Part.

  In the internal combustion engine control apparatus, when the engine speed is set in the low speed range, the engine control means has a first identification number that matches the first upper limit speed among the damage avoidance hydraulic pressure determination values. A hydraulic pressure value is obtained, and a hydraulic pressure level having a third specific hydraulic pressure value that matches the first specific hydraulic pressure value is set as the first hydraulic pressure determination value from among a plurality of hydraulic pressure levels.

  For this reason, the engine control means sets the hydraulic pressure level that has decreased at a constant rate with respect to the normal level hydraulic pressure as the first hydraulic pressure determination value, and the first hydraulic pressure determination value is less than the first hydraulic pressure determination value. The upper limit number of rotations can be limited. Therefore, the first upper limit rotation speed can be set for the first hydraulic pressure determination value that is more marginal than the damage avoidance hydraulic pressure determination value when the hydraulic pressure decreases, and the hydraulic pressure becomes less than the first hydraulic pressure determination value. The vehicle can be accelerated by increasing the number of revolutions of the internal combustion engine to the first upper limit number of revolutions while preventing damage to the supplied parts.

  In addition, when the engine speed is set in the high speed range, the engine control means obtains a second specific oil pressure value that matches the second upper limit speed from the damage avoidance oil pressure determination value. The hydraulic pressure level having the fourth specific hydraulic pressure value that matches the second hydraulic pressure determination value is set as the second hydraulic pressure determination value from among the plurality of hydraulic pressure levels.

  For this reason, the engine control means sets a level that decreases at a constant rate relative to the normal level hydraulic pressure as the second hydraulic pressure determination value, and when the engine control means becomes less than the second hydraulic pressure determination value, the second upper limit The number of rotations can be limited. Accordingly, the second upper limit rotation speed can be set for the second hydraulic pressure determination value that has a margin more than the damage avoidance hydraulic pressure determination value when the hydraulic pressure decreases, and the hydraulic pressure becomes less than the second hydraulic pressure determination value. The vehicle can be accelerated by increasing the number of revolutions of the internal combustion engine to the second upper limit number of revolutions while preventing damage to the supplied parts.

  In the control device for an internal combustion engine of (3) above, (4) the plurality of hydraulic pressure levels set in the hydraulic pressure level setting unit are configured to correspond to the amount of oil stored in the oil storage means.

  In this internal combustion engine control device, the engine control means is adapted to make the plurality of hydraulic pressure levels set in the hydraulic pressure level setting section correspond to the amount of oil stored in the oil storage means, so that it is stored in the oil storage means. The first hydraulic pressure determination value and the second hydraulic pressure determination value can be set based on the remaining amount of oil, and the first upper limit is set for the hydraulic pressure determination value that has more margin than the damage avoidance hydraulic pressure determination value when the hydraulic pressure decreases. The rotation speed and the second upper limit rotation speed can be set.

  In the control device for an internal combustion engine of (1) to (4), (5) the internal combustion engine is provided in the intake pipe for introducing intake air into the internal combustion engine, and the intake pipe, and is supplied to the internal combustion engine. A throttle valve that adjusts the amount of intake air to be driven and a drive member that drives the throttle valve, and the engine control means is configured to start from the oil pump when the normal rotational speed is in a low rotational speed range. On the condition that the discharged hydraulic pressure is less than the first hydraulic pressure determination value, the drive member is driven to control the throttle valve opening to the closed side, thereby increasing the rotational speed of the internal combustion engine. If the normal rotation speed is in the high rotation speed range, the drive member is driven and driven on the condition that the hydraulic pressure discharged from the oil pump is less than the second hydraulic pressure determination value. Slot By controlling the closing side opening of Rubarubu, and a limiting the increase in the rotational speed of the internal combustion engine.

  In this internal combustion engine control apparatus, the engine control means drives the drive member to close the opening of the throttle valve on condition that the hydraulic pressure is less than the first hydraulic pressure determination value or the second hydraulic pressure determination value. By controlling to the side, the increase in the number of revolutions of the internal combustion engine is limited, so that the supply site can be prevented from being burned when the hydraulic pressure is abnormal, and the supply site can be burned at an early stage. Can be prevented.

  In the control apparatus for an internal combustion engine of (1) to (5), (6) warning means for warning that the hydraulic pressure is abnormal based on an abnormal signal output from the engine control means, and the engine control The means outputs a warning signal to the warning means on condition that the hydraulic pressure discharged from the oil pump is less than the first hydraulic pressure judgment value when the normal rotational speed is in a low rotational speed range. When the normal rotational speed is in the high rotational speed range, the warning signal is output to the warning means on condition that the hydraulic pressure discharged from the oil pump is less than the second hydraulic pressure determination value. It is configured.

  In this internal combustion engine control device, the engine control means issues a warning by the warning means on the condition that the hydraulic pressure discharged from the oil pump is less than the first hydraulic pressure judgment value or the second hydraulic pressure judgment value. The driver can be warned that the oil stored in the oil storage means is insufficient. For this reason, it is possible to prompt the driver to check the oil in the oil storage means or to replenish the oil storage means with oil.

  (3) In the control device for an internal combustion engine according to (3) to (6), (7) the engine control means includes: a rotation speed of the internal combustion engine; a temperature of oil discharged from the oil pump; and a discharge from the oil pump. The hydraulic pressure level is set based on the hydraulic pressure to be set.

  In this internal combustion engine control apparatus, the engine control means sets the hydraulic pressure level based on the rotational speed of the internal combustion engine, the temperature of the oil discharged from the oil pump, and the hydraulic pressure. The optimum hydraulic pressure level can be set according to the oil pressure abnormality and detected with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the range which can continue normal driving | running | working according to a normal rotation speed range can be expanded, and the control apparatus of the internal combustion engine which can suppress giving a driver uncomfortable feeling can be provided.

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 a vehicle including 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 configuration diagram of the engine. 1 is a diagram illustrating an embodiment of a control apparatus for an internal combustion engine according to the present invention, and is a block diagram illustrating a supply portion of an engine and a flow of oil. 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 basic 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 hydraulic pressure abnormality 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 a vehicle type, an engine displacement, the kind of transmission, a maximum gear ratio, a power weight ratio, a normal rotation speed, and an upper limit rotation speed. It is a figure 1 is a diagram showing an embodiment of a control apparatus for an internal combustion engine according to the present invention, and is a flowchart of an engine control process when initial setting of a hydraulic pressure abnormality determination map is performed. 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 an engine control process in case a normal rotation speed is set to the low rotation speed area. 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 an engine control process when a normal rotation speed is set to the high rotation speed area.

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, a transmission 3, an oil supply device 4, and a control device 5 for the internal combustion engine.

  As shown in FIG. 2, the engine 2 performs a series of four strokes consisting of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while the piston 10 accommodated in a reciprocating motion in a cylinder (not shown) reciprocates twice. It is a so-called 4-cycle gasoline engine.

  The engine 2 is an in-line four-cylinder engine having 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 piston 10, a variable valve timing mechanism (hereinafter referred to as VVT) 11, a crankshaft 12 constituting an output shaft, a cylinder head 13, a cylinder block 14, and an engine block 15 comprising a crankcase. And a fuel injection device (not shown) for injecting fuel into the cylinder.

  The crankshaft 12 is rotatably supported by the engine block 15 via a crank journal 12a. The crankshaft 12 is connected to the piston 10 via a connecting rod 16 so that the reciprocating motion of the piston 10 is transmitted to rotate. The connecting rod 16 is connected to the crankpin 12b of the crankshaft 12.

The intake camshaft 17 and the exhaust camshaft 18 are rotatably supported by the cylinder head 13 via a cam journal 19 (see FIG. 3).
The intake camshaft 17 and the exhaust camshaft 18 are connected to the crankshaft 12 through a chain 20, and the power of the crankshaft 12 is transmitted through the chain 20 so that the intake cam 17a and the exhaust cam 18a are connected. The intake valve 21 and the exhaust valve 22 are opened and closed.

  In FIG. 1, the transmission 3 is connected to the output side of the engine 2 and shifts the rotation of the engine 2, that is, the rotation of the crankshaft 12. Drive wheels 26L and 26R are connected to the output side of the transmission 3 through, for example, a propeller shaft 23, a differential device 24, and drive shafts 25L and 25R. In other words, the output torque of the engine 2 is input to the transmission 3 and is shifted according to the transmission gear ratio set in the transmission 3, and transmitted to the drive wheels 26L and 26R as drive torque. .

  The transmission 3 is a planetary gear type automatic transmission that is connected to the crankshaft 12 via a torque converter (not shown) and sets a gear ratio using a clutch, a brake, and a planetary gear device. A belt type continuously variable transmission (CVT) that adjusts in stages, a manual transmission that is connected to the crankshaft 12 via a clutch mechanism, or the like is used.

  As shown in FIGS. 1 and 2, the oil supply device 4 includes an oil pan 31 as an oil storage unit, an oil strainer 32, an oil pump 33, and an oil filter 34 that filters oil discharged from the oil pump 33. And an oil supply path 35 (see FIG. 3) including an oil path 35a and an oil recirculation path 35b.

  An oil strainer 32 is immersed in the oil pan 31, and the oil strainer 32 filters oil stored in the oil pan 31.

  The oil stored in the oil pan 31 is sucked up by the oil pump 33 through the oil strainer 32 and discharged from the oil pump 33 to the oil passage 35a. An oil filter 34 is interposed in the oil passage 35a, and the oil filter 34 removes foreign matters mixed in the oil.

  The oil pump 33 is composed of, for example, a trochoid pump or a gear pump, and is connected to the crankshaft 12 via the chain 20. The oil pump 33 is driven at a constant speed by the crankshaft 12 on a separate axis from the crankshaft 12. ing. The oil pump 33 may have a structure that is directly connected to the crankshaft 12 and driven at a constant speed by the crankshaft 12 regardless of the chain 20.

  As shown in FIGS. 2 and 3, a main gallery 36 is provided downstream of the oil passage 35 a, and the main gallery 36 extends along the crankshaft 12 in the wall surface of the cylinder block 14.

  The main gallery 36 is supplied with oil pressurized by the oil pump 33, and the oil supplied to the main gallery 36 is branched and supplied to the cylinder head 13 and the cylinder block 14. It has become.

  The oil branched and supplied to the cylinder head 13 and the cylinder block 14 is supplied to the supply target portion of the engine 2.

  For example, in the cylinder block 14, as the oil for lubricating the sliding parts such as the crank journal 12 a, the crank pin 12 b, the connecting rod 16, and the operating oil of the oil jet 37 constituting the hydraulic drive parts, The oil is used for lubricating the cam journal 19 of the intake camshaft 17 and the exhaust camshaft 18, and as the hydraulic oil for the VVT 11 and the lash adjuster 38 constituting the hydraulic drive parts.

  In the present embodiment, the portion to be supplied is composed of sliding portions such as the crank journal 12a, the crank pin 12b, the connecting rod 16, and the piston 10, and hydraulic drive parts such as the oil jet 37, the lash adjuster 38, and the VVT 11. Has been.

  Here, the VVT 11 is a mechanism that controls the intake valve 21 at an optimal opening / closing timing in accordance with the operating state. The VVT 11 includes a VVT controller provided at the axial end of the intake camshaft 17.

  The VVT 11 can advance or retard the opening / closing timing of the intake valve 21 by changing the phase of the intake camshaft 17 with respect to the cam sprocket by supplying hydraulic pressure to each VVT controller.

  The hydraulic pressure supplied to each VVT controller of the VVT 11 is controlled by an oil control valve (OCV: Oil Control Valve) 27 on the intake side. Note that the VVT 11 may control the exhaust valve 22 in addition to the intake valve 21 at an optimal opening / closing timing.

  The oil jet 37 injects oil toward the bottom surface of the piston 10 of the engine 2 to cool the piston 10 that is exposed to the combustion gas and has a high thermal load. For example, abnormal combustion during high load operation To prevent knocking and to suppress knocking.

  The oil supplied to the supply site is then dropped inside the engine block 15 and returned to the oil pan 31 again. The oil supply path 35 of the oil supply device 4 includes an oil passage 35 a, an oil recirculation path 35 b, and a main gallery 36, and after supplying the oil stored in the oil pan 31 to the supply target portion of the engine 2. A circulation path for collecting in the oil pan 31 is configured.

  That is, the oil supply path 35 is an oil circulation path until the oil stored in the oil pan 31 is supplied to the supply site of the engine 2 by the oil pump 33 and then collected in the oil pan 31.

  As shown in FIG. 1, the oil recirculation passage 35b is connected to the oil passage 35a on the discharge side of the oil pump 33, and a relief valve 39 is provided on the oil recirculation passage 35b. The relief valve 39 operates (opens a valve) when the oil pressure (discharge pressure) on the discharge side of the oil pump 33 exceeds a predetermined value to release oil into the oil pan 31 or the oil pump 33.

  In FIG. 1, an intake pipe 41 for introducing intake air to the engine 2 is connected to the engine 2, and the intake pipe 41 is provided with a throttle valve 42. The throttle valve 42 adjusts the amount of intake air introduced into the engine 2 by adjusting the opening in the intake pipe 41, that is, the opening of the intake passage in response to depression of an accelerator pedal (not shown). It has become.

  The throttle valve 42 is driven by a drive motor 43, and the drive motor 43 adjusts the opening degree of the throttle valve 42 based on a drive signal from the ECU 51.

  The intake pipe 41 introduces intake air into the combustion chamber of the cylinder via an intake port formed in the cylinder head 13, and the intake port is opened and closed by the intake valve 21. Yes.

  As shown in FIG. 1, the control device 5 includes an engine control unit (hereinafter simply referred to as ECU) 51, a hydraulic pressure sensor 52, an oil temperature sensor 53, a crank angle sensor 54, and a warning lamp 55.

  The oil pressure sensor 52 is provided in the oil passage 35 a on the discharge side of the oil pump 33. The hydraulic sensor 52 detects the hydraulic pressure supplied from the oil pump 33 to the supply site, and outputs a signal corresponding to the hydraulic pressure to the ECU 51. Note that the hydraulic sensor 52 may be provided in the main gallery 36.

  The oil temperature sensor 53 is provided in the oil passage 35a on the discharge side of the oil pump 33, and detects the temperature of oil discharged from the oil pump 33 (hereinafter referred to as oil temperature). The oil temperature sensor 53 may be provided in the main gallery 36.

  The oil temperature sensor 53 is constituted by, for example, a thermistor whose resistance value changes according to the oil temperature, and outputs a voltage that changes according to the change of the resistance value to the ECU 51 as a signal representing the oil temperature.

  The crank angle sensor 54 is provided in the vicinity of the crankshaft 12, and the crank angle sensor 54 is, for example, an electromagnetic pickup, and is a signal rotor (not shown) provided on the crankshaft 12 when the crankshaft 12 rotates. A pulse-like signal (output pulse) corresponding to each tooth is generated and output to the ECU 51. The ECU 51 calculates the engine speed by measuring the number of pulses per unit time based on the output information of the crank angle sensor 54.

  The ECU 51 includes a CPU (Central Processing Unit) 51a, a ROM (Read Only Memory) 51b, a RAM (Random Access Memory) 51c, a drive motor 43, a hydraulic sensor 52, an oil temperature sensor 53, a crank angle sensor 54, and a warning lamp. And an input / output interface 51d to which 55 is connected.

  The ROM 51b is composed of, for example, an EEPROM or an EPROM. The ROM 51b stores various control programs including an engine control program, a plurality of maps referred to when executing these various control programs, and the like.

  The RAM 51c is a memory that temporarily stores calculation results in the CPU 51a, data input from the various sensors described above, and the like, and is a nonvolatile memory that also constitutes a part of the work area.

  FIG. 4 is a basic map for determining the hydraulic pressure abnormality stored in the ROM 51b. This basic map shows the engine speed (rpm) and the temperature of oil discharged from the oil pump 33 (hereinafter referred to as oil temperature) ( And a plurality of hydraulic pressure levels are set based on the pressure of oil discharged from the oil pump 33 (hereinafter referred to as hydraulic pressure).

  As the hydraulic pressure level, the hydraulic pressure value Pf is set such that the oil level in the oil pan 31 is L (Low) level, that is, a level greater than the minimum level that requires oil replenishment. The oil pressure value Pf is set to, for example, the oil pressure value when the oil in the oil pan 31 has a normal oil pressure that is 90% lower than the F (Full) level.

  The hydraulic pressure levels are set to hydraulic pressure values P1, P2, and P3 that decrease at a constant rate with respect to the hydraulic pressure value Pf. These hydraulic pressure values Pf, P1, P2, and P3 are determined according to the engine speed and the hydraulic pressure. Associated.

  When the oil level is at a normal level, the hydraulic pressure supplied from the oil pump 33 to the supply site is a normal level, and the oil pressure level is such that the lubrication site constituting the supply site does not burn. .

  In the present embodiment, for example, the hydraulic pressure value P1 indicates a hydraulic pressure value that is 60% of the hydraulic pressure value Pf, the hydraulic pressure value P2 indicates a hydraulic pressure value that is 50% of the hydraulic pressure value Pf, The value P3 indicates a hydraulic pressure value that is 30% of the hydraulic pressure value Pf. However, the hydraulic pressure value P3 is greater than or equal to the L level.

  Further, in the basic map, a damage avoidance oil pressure determination value Pp having a characteristic that the oil pressure increases with an increase in the engine speed is set, and this damage avoidance oil pressure determination value Pp is large enough not to damage the supplied part. This is the upper limit oil pressure for determining the hydraulic pressure abnormality. The damage avoidance hydraulic pressure determination value Pp has a characteristic that the hydraulic pressure increases rapidly when the engine speed is in a high speed range.

When the hydraulic pressure discharged from the oil pump 33 falls below the damage avoidance hydraulic pressure determination value Pp, there is a possibility that the sliding parts such as the crank journal 12a, the crankpin 12b, the connecting rod 16, the piston 10 and the like will be burned. For this reason, the damage avoidance hydraulic pressure determination value Pp is set as the upper limit hydraulic pressure for determining the hydraulic pressure abnormality that does not damage the supplied part.
The oil pressure values Pf, P1, P2, and P3 have characteristics that the rate of change of oil pressure is smaller than the damage avoidance determination value Pp when the engine speed is in the high engine speed range.

  FIG. 5 is a hydraulic pressure abnormality determination map. In this hydraulic pressure abnormality determination map, the first hydraulic pressure determination value Pa for determining the hydraulic pressure abnormality and the increase of the engine speed when the normal rotation speed is set in the low rotation speed range. A first upper limit rotational speed Na for suppressing the above is set.

  Further, the hydraulic pressure abnormality determination map includes a second hydraulic pressure determination value Pb for determining a hydraulic pressure abnormality and a second upper limit rotation for suppressing an increase in the engine speed when the normal rotational speed is set in the high rotational speed range. A number Nb is set.

  The first oil pressure determination value Pa is set to a value larger than the damage avoidance oil pressure determination value Pp so as to increase in accordance with the engine speed in the low engine speed range. Further, the second hydraulic pressure determination value Pb is set to a value larger than the first hydraulic pressure determination value Pa so as to increase according to the engine speed, and the second upper limit rotation speed Nb is set to the first It is set on the higher rotational speed range side than the upper limit rotational speed Na.

  The first upper limit rotational speed Na and the second upper limit rotational speed Nb are calculated based on the engine displacement, the maximum gear ratio, and the power / weight ratio, and are specific to the first upper limit rotational speed Na or the second Is stored in the ROM 51b. In the hydraulic pressure abnormality determination map of FIG. 5, the damage avoidance hydraulic pressure Pp and the hydraulic pressure values Pf, P1, P2, and P3 are shown for convenience of explanation.

FIG. 6 is a diagram showing the relationship among the vehicle type, engine displacement, type of transmission 3, maximum gear ratio, power weight ratio, normal rotation speed, and upper limit rotation speed.
Here, the types of transmission are classified into manual transmission (MT), belt type continuously variable transmission (CVT), and automatic transmission (AT). The upper limit rotational speed is determined by the magnitude of engine displacement, maximum gear ratio, and power weight ratio (vehicle weight / maximum output).

  Specifically, the upper limit rotational speed is set to a higher rotational speed region as the maximum gear ratio is larger and the power weight ratio is smaller. Further, the lower the maximum gear ratio and the larger the power weight ratio, the lower the upper limit rotational speed is set. That is, the vehicle 1 in which the upper limit rotational speed is set in the high rotational speed range is the normal rotational speed is in the high rotational speed range, and the vehicle 1 in which the upper limit rotational speed is set in the low rotational speed range is in the normal rotational speed. .

  For example, the higher the engine displacement and the smaller the power / weight ratio, the better the acceleration, so the vehicle 1 with a small power / weight ratio has a normal rotational speed in the low rotational speed range, and an upper limit rotational speed for the low rotational speed range is set. Is done. Further, in the vehicle 1 having a large engine displacement and a large power weight ratio, the normal rotation speed is in the high rotation speed range, and the upper limit rotation speed for the high rotation speed range is set.

  Further, the smaller the maximum gear ratio, the smaller the rotation speed of the crankshaft 12 per rotation of the drive wheels 26L, 26R. Therefore, the normal rotation speed becomes a low rotation speed range, and the upper limit rotation speed for the low rotation speed range is set. The

  Further, as the maximum gear ratio is larger, the number of rotations of the crankshaft 12 per rotation of the drive wheels 26L and 26R is larger, so the number of rotations of the drive wheels 26L and 26R per rotation of the crankshaft 12 is smaller. The rotation speed becomes a high rotation speed range, and an upper limit rotation speed for the high rotation speed range is set.

  As shown in FIG. 6, for example, the vehicle 1 having CVT has a normal rotation speed set in a low rotation speed range as compared with the vehicle 1 having MT, and the vehicle having MT has a normal rotation speed in a high rotation speed range. Tend to be set. The ROM 51b stores an engine displacement, a power weight ratio, and a maximum gear ratio according to the vehicle type for each vehicle type.

  The ECU 51 calculates the normal rotation speed based on the engine displacement, the maximum gear ratio, and the power / weight ratio stored in the ROM 51b, and calculates the first upper limit rotation speed Na or the second upper limit rotation speed Nb based on the calculation result. Set.

  The first upper limit rotational speed Na can be said to be in a low rotational speed range as compared with the second upper limit rotational speed Nb. In the present invention, the normal rotational speed is in a different rotational speed range. The upper limit number of rotations having a different size can be set in accordance with each rotation number range.

  Further, in the hydraulic pressure abnormality determination map shown in FIG. 5, when the normal rotation speed is set in the low rotation speed range, the specific hydraulic pressure associated with the first upper limit rotation speed Na in the damage avoidance hydraulic pressure determination value Pp. A hydraulic pressure value P3 having a specific hydraulic pressure value Pa2 that matches the value Pa1 (for example, 100 kPa) is set as the first hydraulic pressure determination value Pa.

That is, among the hydraulic pressure values P1, P2, and P3, the hydraulic pressure value P3 passing through the intersection point X1 between the first upper limit rotation speed Na and the damage avoiding hydraulic pressure determination value Pp is set as the first hydraulic pressure determination value Pa.
In the present embodiment, the specific oil pressure value Pa1 constitutes the first specific oil pressure value, and the specific oil pressure value Pa2 constitutes the third specific oil pressure value.

  The first hydraulic pressure determination value Pa is set at a higher hydraulic pressure side than the damage avoiding hydraulic pressure determination value Pp in the lower rotation speed range than the first upper limit rotation speed Na, and is higher than the first upper limit rotation speed Na. The damage avoidance hydraulic pressure determination value Pp is set to a lower hydraulic pressure side.

  Further, in the abnormal hydraulic pressure determination map shown in FIG. 5, when the normal rotational speed is set in the high rotational speed range, the damage avoiding hydraulic pressure determination value Pp is associated with the second upper limit rotational speed Nb. A hydraulic pressure value P2 having a specific hydraulic pressure value Pb2 that matches the hydraulic pressure determination value Pb1 (for example, 200 kPa) is set as the second hydraulic pressure determination value Pb.

That is, among the hydraulic pressure values P1, P2, and P3, the hydraulic pressure value P3 passing through the intersection X2 between the second upper limit rotation speed Nb and the damage avoiding hydraulic pressure determination value Pp is set as the second hydraulic pressure determination value P2.
In the present embodiment, the specific hydraulic pressure value Pb1 constitutes the second specific hydraulic pressure value, and the specific hydraulic pressure value Pb2 constitutes the fourth specific hydraulic pressure value.

  The second hydraulic pressure determination value Pb is set at a higher hydraulic pressure side than the damage avoiding hydraulic pressure determination value Pp in the lower rotation speed range than the second upper limit rotation speed Nb, and is higher than the second upper limit rotation speed Nb. The damage avoidance hydraulic pressure determination value Pp is set to a lower hydraulic pressure side.

  The ECU 51 of the present embodiment has a characteristic that the hydraulic pressure increases as the engine speed increases, and the hydraulic pressure supplied from the oil pump 33 to the supply site is a normal level hydraulic pressure value Pf and a normal level hydraulic pressure value Pf. The hydraulic pressure level setting unit is configured to set the hydraulic pressure values P1, P2, and P3, which are a plurality of hydraulic pressure levels at which the hydraulic pressure decreases at a constant rate.

  Further, the ECU 51 sets the normal rotation speed to a low rotation speed range or a high rotation speed from the engine displacement, the power weight ratio, and the maximum gear ratio of the transmission 3, and the first upper limit rotation speed Na or the second upper limit. An upper limit rotational speed setting unit for setting the rotational speed N2 is configured. The first upper limit rotational speed Na or the second upper limit rotational speed N2 may be set from one of the power weight ratio and the maximum gear ratio.

  In addition, when the normal rotation speed is set in the low rotation speed range, the ECU 51 obtains a specific hydraulic pressure value Pa1 that matches the first upper limit rotation speed Na from the damage avoidance hydraulic pressure determination value Pp, and outputs a plurality of hydraulic pressures. A first hydraulic pressure determination value setting unit that sets the hydraulic pressure level having the specific hydraulic pressure value Pb2 that matches the specific hydraulic pressure value Pa1 among the values P1, P2, and P3 to the first hydraulic pressure determination value Pa is configured.

  Further, when the normal rotation speed is set in the high rotation speed range, the ECU 51 obtains a specific hydraulic pressure value Pb1 that matches the second upper limit rotation speed Na from the damage avoidance hydraulic pressure determination value Pp, The second hydraulic pressure determination value setting unit is configured to set the hydraulic pressure level having the specific hydraulic pressure value Pb2 that matches the specific hydraulic pressure value Pb1 to the second hydraulic pressure determination value Pb.

  Further, the ECU 51 sets the engine speed to the first upper limit speed Na on condition that the hydraulic pressure discharged from the oil pump 33 becomes less than the first hydraulic pressure determination value Pa.

  In addition, when the normal rotation speed is set in the high rotation speed range, the ECU 51 sets the engine rotation speed on the condition that the hydraulic pressure discharged from the oil pump 33 is less than the second hydraulic pressure determination value Pb. The second upper limit rotational speed Nb is set.

  The ECU 51 is caused by a decrease in the oil level in the oil pan 31 on condition that the hydraulic pressure discharged from the oil pump 33 is less than the first hydraulic pressure determination value Pa or less than the second hydraulic pressure determination value Pb. It is determined that the hydraulic pressure is abnormal, and an abnormal signal is output to the warning lamp 55.

  The warning lamp 55 is lit or blinked when an abnormality signal is input from the ECU 51 to warn of a hydraulic pressure abnormality, thereby warning the driver that the oil level in the oil pan 31 has decreased.

  Further, when the ECU 51 determines that the hydraulic pressure is abnormal, the ECU 51 transmits a control signal to the drive motor 43. When a control signal is input from the ECU 51, the drive motor 43 controls the throttle valve 42 to the closed side, so that the rotational speed of the engine 2 becomes equal to or higher than the first upper limit rotational speed Na or the second upper limit rotational speed Nb. It is designed to suppress the rise. Further, the ECU 51 of the present embodiment constitutes engine control means.

  Further, the basic map shown in FIG. 4 is a plurality of maps in which the engine speed, the hydraulic pressure values Pf, P1, P2, P3 and the damage avoidance determination hydraulic pressure Pp at the engine speed are assigned for each oil temperature (° C.). It is composed of

  FIG. 4 shows an example of a map in which the engine speed, oil pressure values Pf, P1, P2, P3 and the damage avoidance determination oil pressure Pp at the engine speed are assigned to the oil temperature of T ° C. The hydraulic pressure values Pf, P1, P2, and P3 and the damage avoidance determination hydraulic pressure Pp are set to a lower pressure side as the oil temperature becomes lower and the oil temperature becomes higher.

  In the basic map, the engine speed, the oil pressure values Pf, P1, P2, P3 and the damage avoidance determination oil pressure Pp at the engine speed may be assigned for each oil temperature, or for each constant oil temperature range. The engine speed and the hydraulic pressure values Pf, P1, P2, P3 and the damage avoidance determination hydraulic pressure Pp at the engine speed may be assigned (for example, every 10 ° C.).

Next, the engine control process of the engine 2 will be described based on FIGS.
FIG. 7 is a flowchart of an engine control process executed by the ECU 51 of the control device 5, and shows a process for initializing the hydraulic pressure abnormality determination map shown in FIG. The flowchart in FIG. 7 is an engine control program stored in the ROM 51b, and this engine control program is executed by the CPU 51a.

  In FIG. 7, first, the CPU 51a reads a basic map (see FIG. 4) stored in the ROM 51b (step S1). At this time, the CPU 51a starts reading from the basic map associated with the minimum oil temperature. Next, the CPU 51a calculates the upper limit rotational speed based on the engine displacement, the maximum gear ratio, and the power / weight ratio stored in the ROM 51b (step S2).

  Next, the CPU 51a calculates a specific hydraulic pressure value that passes through the intersection X between the upper limit rotation speed calculated in step S2 and the damage avoidance hydraulic pressure determination value Pp among the hydraulic pressure values P1, P2, and P3, and determines the hydraulic pressure abnormality determination pressure. A value is set (step S3).

  Specifically, in the process of step S3, when the normal rotational speed is in the low rotational speed range, the CPU 51a determines the specific hydraulic pressure value that matches the first upper limit rotational speed Na from the damage avoiding hydraulic pressure determination value Pp. Pa1 is obtained, and a hydraulic pressure value P3 having a specific hydraulic pressure value Pa2 that matches the specific hydraulic pressure value Pa1 among the hydraulic pressure values P1, P2, and P3 is set as the first hydraulic pressure determination value Pa.

  Further, when the normal rotation speed is in the high rotation speed range, the CPU 51a obtains a specific hydraulic pressure value Pb1 that matches the second upper limit rotation speed Nb from the damage avoidance hydraulic pressure determination value Pp, and determines the hydraulic pressure values P1, P2. , P3, a hydraulic pressure value P2 having a specific hydraulic pressure value Pb2 that matches the specific hydraulic pressure value Pb1 is set as the second hydraulic pressure determination value Pb.

  Thus, by obtaining the intersection point X1 between the specific hydraulic pressure values Pa1 and Pa2 or the intersection point X2 between the specific hydraulic pressure values Pb1 and Pb2, the initial processing of the hydraulic pressure abnormality determination map shown in FIG. 5 is performed.

  Next, the CPU 51a determines whether or not the initial setting of the abnormal hydraulic pressure determination map corresponding to all the temperatures has been completed (step S4). The basic map is read and the processes of steps S1 to S3 are executed.

  When the CPU 51a determines that the initial setting of the abnormal oil pressure determination map corresponding to all temperatures has been completed, the CPU 51a ends the current process.

  8 and 9 are flowcharts of an engine control process executed by the ECU 51 of the control device 5, and show a process for performing the engine control. The flowcharts of FIGS. 8 and 9 are engine control programs stored in the ROM 51b, and this engine control program is executed by the CPU 51a.

First, the engine control process when the normal rotation speed is set in the low rotation speed range will be described based on FIG.
In FIG. 8, after reading the oil temperature discharged from the oil pan 31 based on the detection information from the oil temperature sensor 53 (step S11), the CPU 51a reads this oil pressure from the oil pressure abnormality determination map stored in the ROM 51b. A hydraulic pressure abnormality determination map corresponding to the temperature is read (step S12).

  Next, the CPU 51a reads the hydraulic pressure Po based on the detection information of the hydraulic sensor 52 (step S13), and then calculates the engine speed No based on the detection information of the crank angle sensor 54 (step S14).

  Next, the CPU 51a determines whether or not the engine speed No is less than the first upper limit speed Na (step S15), and determines that the engine speed No is less than the first upper limit speed Na. In this case, it is determined whether or not the hydraulic pressure Po of the hydraulic pressure sensor 52 is less than the first hydraulic pressure abnormality determination value Pa (step S16).

  When the CPU 51a determines that the oil pressure Po of the oil pressure sensor 52 is equal to or higher than the first oil pressure abnormality determination value Pa, the CPU 51a determines that the oil pressure is normal and the oil level in the oil pan 31 is normal. Then, the process returns to step S13.

  When the CPU 51a determines that the oil pressure Po of the oil pressure sensor 52 is less than the first oil pressure abnormality determination value Pa, the CPU 51a determines that the oil pressure is abnormal and outputs an abnormality signal to the warning lamp 55. (Step S17), the current process is terminated.

  The oil pressure abnormality occurs because the oil level in the oil pan 31 is lowered and the oil pump 33 is in the air sucking state. The driver can turn on the oil lamp 31 by turning on or blinking the warning lamp 55. It is possible to recognize that there was a shortage of oil.

  Further, since the engine speed No at this time is less than the first upper limit speed Na, even if a decrease in oil pressure is detected in a lower speed range than the first upper limit speed Na, It is possible to perform acceleration by increasing the engine speed up to an upper limit speed Na of 1.

  If the CPU 51a determines in step S15 that the engine speed No is greater than or equal to the first upper limit speed Na, it determines whether the hydraulic pressure Po of the hydraulic sensor 52 is less than the damage avoidance determination hydraulic pressure Pp. It discriminate | determines (step S18).

  If the CPU 51a determines that the hydraulic pressure Po is greater than or equal to the damage avoidance determination hydraulic pressure Pp, the CPU 51a determines that the hydraulic pressure is normal and returns the process to step S13.

  When the CPU 51a determines that the hydraulic pressure Po is less than the damage avoidance determination hydraulic pressure Pp, the CPU 51a outputs a control signal to the drive motor 43 so that the throttle valve 42 is closed by the drive motor 43. Control (step S19), the engine speed is reduced to the first upper limit speed Na, and the current process is terminated.

  For this reason, in the subsequent operation, even if the amount of depression of the accelerator pedal is increased so that a rotation speed equal to or higher than the first upper limit rotation speed Na is obtained, the engine rotation speed increases to the first upper limit rotation speed Na or higher. It is suppressed. The control of the throttle valve 42 to the closed side is to control the throttle valve 42 to the closed side with respect to the opening degree of the throttle valve associated with the depression of the accelerator pedal.

  That is, the CPU 51a refers to a map in which the opening degree of the accelerator pedal and the opening degree of the throttle valve are associated with each other, and controls the opening degree of the throttle valve to be closer to the closing side than the normal opening degree corresponding to the depression amount of the accelerator pedal. Then reduce the throttle opening. If it does in this way, the amount of intake air supplied to engine 2 will decrease and the increase in the number of rotations of engine 2 will be controlled.

  As a result, it is possible to protect the engine 2 by preventing the crank journal 12a, the crankpin 12b, the connecting rod 16, the piston 10 and the like from being burned.

Next, the engine control process when the normal rotation speed is set in the high rotation speed range will be described based on FIG.
In FIG. 9, after reading the oil temperature discharged from the oil pan 31 based on the detection information from the oil temperature sensor 53 (step S21), the CPU 51a reads this oil pressure from the oil pressure abnormality determination map stored in the ROM 51b. A hydraulic pressure abnormality determination map corresponding to the temperature is read (step S22).

  Next, the CPU 51a reads the hydraulic pressure Po based on the detection information of the hydraulic sensor 52 (step S23), and then calculates the engine speed No based on the detection information of the crank angle sensor 54 (step S24).

  Next, the CPU 51a determines whether or not the engine speed No is less than the second upper limit speed Nb (step S25), and determines that the engine speed No is less than the second upper limit speed Nb. In this case, it is determined whether or not the hydraulic pressure Po of the hydraulic pressure sensor 52 is less than the second hydraulic pressure abnormality determination value Pb (step S26).

  When the CPU 51a determines that the oil pressure Po of the oil pressure sensor 52 is greater than or equal to the second oil pressure abnormality determination value Pb, the CPU 51a determines that the oil pressure is normal and the oil level in the oil pan 31 is normal. Then, the process returns to step S23.

  When the CPU 51a determines that the oil pressure Po of the oil pressure sensor 52 is less than the second oil pressure abnormality determination value Pb, the CPU 51a determines that the oil pressure is abnormal and outputs an abnormality signal to the warning lamp 55. (Step S27), the warning lamp 55 is turned on or blinked, and the current process is terminated.

  Further, since the engine speed No at this time is less than the second upper limit speed Nb, even if a decrease in hydraulic pressure is detected in a lower speed range than the second upper limit speed Nb, The engine speed can be increased to an upper limit engine speed Nb of 2, and acceleration can be performed.

  If the CPU 51a determines in step S25 that the engine speed No is greater than or equal to the second upper limit speed Nb, the CPU 51a determines whether or not the oil pressure Po of the oil pressure sensor 52 is less than the damage avoidance determination oil pressure Pp. It discriminate | determines (step S28).

  If the CPU 51a determines that the hydraulic pressure Po is greater than or equal to the damage avoidance determination hydraulic pressure Pp, the CPU 51a determines that the hydraulic pressure is normal and returns the process to step S23.

  When the CPU 51a determines that the hydraulic pressure Po is less than the damage avoidance determination hydraulic pressure Pp, the CPU 51a outputs a control signal to the drive motor 43 so that the throttle valve 42 is closed by the drive motor 43. Control is performed (step S29), and the engine speed is reduced to the second upper limit value Na.

  For this reason, in subsequent operations, even if the amount of depression of the accelerator pedal is increased so that a rotational speed equal to or higher than the second upper limit rotational speed Nb is obtained, the engine rotational speed increases to the second upper limit rotational speed Nb or higher. Is suppressed.

  As a result, it is possible to protect the engine 2 by preventing the crank journal 12a, the crankpin 12b, the connecting rod 16, the piston 10 and the like from being burned.

  As described above, in the control device 5 of the present embodiment, the ECU 51 sets the damage avoidance hydraulic pressure determination value Pp for hydraulic pressure abnormality determination with a magnitude that does not damage the supplied portion so as to increase according to the engine speed, When the normal rotation speed is set in the low rotation speed range, the first hydraulic pressure determination value Pa that is larger than the damage avoidance hydraulic pressure determination value Pp so as to increase according to the engine rotation speed in the low rotation speed range of the engine 2. And a first upper limit rotational speed Na that limits the increase in the engine rotational speed is set, and the engine is operated on condition that the hydraulic pressure discharged from the oil pump 33 is less than the first hydraulic pressure determination value Pa. The rotation speed is configured to be limited to the first upper limit rotation speed Na.

  For this reason, even when the hydraulic pressure discharged from the oil pump 33 in the lower rotational speed region than the first upper limit rotational speed Na becomes less than the first hydraulic pressure determination value Pa, the first upper limit rotational speed Na. The vehicle speed can be increased by increasing the engine speed. For this reason, it can suppress giving a driver a sense of incongruity.

  Even when the oil pressure is less than the first oil pressure determination value Pa, the first oil pressure determination value Pa is equal to or greater than the damage avoidance oil pressure determination value Pp, so that the supply site is not less than the rotation speed that is not damaged. The engine speed can be increased to the first upper limit speed Na. For this reason, it is possible to accelerate the vehicle while avoiding the occurrence of baking or the like at the supply site.

  Further, the ECU 51 sets a second oil pressure determination value Pb larger than the first oil pressure determination value Na so as to increase according to the engine speed when the normal rotation speed is set in the high rotation speed range. In addition, the second upper limit rotational speed Nb is set on the higher rotational speed range side than the first upper limit rotational speed Na, and the hydraulic pressure discharged from the oil pump 33 is less than the second hydraulic pressure determination value Pb. As a condition, the engine speed is limited to the second upper limit speed Nb.

  For this reason, even when the hydraulic pressure discharged from the oil pump 33 in the rotational speed region lower than the second upper limit rotational speed Nb becomes less than the second hydraulic pressure determination value Pb, the hydraulic pump discharges from the oil pump 33. The vehicle speed can be increased by increasing the engine speed up to the second upper limit speed Nb higher than the first upper limit speed Na after the hydraulic pressure becomes less than the second hydraulic pressure determination value Pb. . Therefore, it is possible to suppress the driver from feeling uncomfortable.

  Further, since the second hydraulic pressure determination value Pb is set on the higher hydraulic pressure side with respect to the first hydraulic pressure determination value Pa higher than the damage avoidance hydraulic pressure determination value, the second hydraulic pressure determination value Pb is equal to or higher than the rotation speed at which the supplied part is not damaged. The engine speed can be increased to an upper limit speed Na of 2. For this reason, it is possible to accelerate the vehicle while avoiding the occurrence of baking or the like at the supply site.

  Further, in the control device 5 of the present embodiment, when the normal rotation speed is set in the low rotation speed range, the ECU 51 determines from the first upper limit rotation speed Na associated with the first hydraulic pressure determination value Pa. The engine speed is set to the first upper limit on condition that the first upper limit speed Na is set to a lower hydraulic pressure side than the damage avoidance oil pressure determination value Pp at a high speed and is less than the damage avoidance oil pressure determination value Pp. It is comprised so that it may restrict | limit to the rotation speed Na.

  For this reason, when the hydraulic pressure becomes less than the damage avoidance hydraulic pressure determination Pp value during traveling in a higher rotational speed range than the first upper limit rotational speed Na, the first upper limit rotational speed Na is limited to the supply site. It is possible to prevent burning and the like from occurring at an early stage.

  Further, when the normal rotation speed is set in the high rotation speed range, the ECU 51 sets the second upper limit rotation speed at a rotation speed higher than the second upper limit rotation speed Nb associated with the second hydraulic pressure determination value Pb. Nb is set to a lower hydraulic pressure side than the damage avoidance oil pressure determination value Pp, and the engine speed is set to the second upper limit engine speed on condition that the damage is less than the damage avoidance oil pressure determination value Pp. Yes.

  For this reason, when the hydraulic pressure becomes less than the damage avoidance hydraulic pressure determination value Pp during traveling in a higher rotational speed range than the second upper limit rotational speed Nb, the second upper limit rotational speed Nb is limited to the supply target portion. It is possible to prevent burning and the like from occurring at an early stage.

  Further, in the control device 5 of the present embodiment, the ECU 51 matches the first upper limit rotation speed Na from the damage avoidance hydraulic pressure determination value Pp when the normal rotation speed is set in the low rotation speed range. The specific oil pressure value Pa1 is obtained, and the oil pressure value P3 having the specific oil pressure value Pa2 that matches the specific oil pressure value Pa1 among the oil pressure values P1, P2, and P3 is set as the first oil pressure determination value Pa.

  For this reason, the hydraulic pressure value P3 that has decreased at a constant rate with respect to the hydraulic pressure value Pf at the normal level is set as the first hydraulic pressure determination value Pa, and the first hydraulic pressure value P3 is less than the first hydraulic pressure determination value Pa. It can restrict | limit to upper limit rotation speed Na. Therefore, the first upper limit rotational speed Na can be set for the hydraulic pressure determination value that has a margin more than the damage avoidance hydraulic pressure determination value Pp when the hydraulic pressure decreases, and the hydraulic pressure becomes less than the first hydraulic pressure determination value Pa. The vehicle can be accelerated by increasing the engine speed to the first upper limit speed Na while preventing damage to the supplied part.

  Further, when the normal rotation speed is set in the high rotation speed range, the ECU 51 obtains a specific hydraulic pressure value Pb1 that matches the second upper limit rotation speed Nb from the damage avoidance hydraulic pressure determination value Pp, and determines the hydraulic pressure value P1. , P2, and P3, a hydraulic pressure value P2 having a specific hydraulic pressure value Pb2 that matches the specific hydraulic pressure value Pb1 is set as the second hydraulic pressure determination value Pb.

  For this reason, a level that decreases at a constant rate with respect to the normal level hydraulic pressure is set as the second hydraulic pressure determination value P2, and when it becomes less than the second hydraulic pressure determination value P2, the second upper limit rotation speed Nb Can be limited to.

  Therefore, the second upper limit rotation speed Nb can be set with respect to the second hydraulic pressure determination value Pb that is more marginal than the damage avoidance hydraulic pressure determination value Pp when the hydraulic pressure decreases, and the hydraulic pressure is less than the second hydraulic pressure determination value Pb. Then, the vehicle can be accelerated by increasing the engine speed up to the second upper limit speed Nb while preventing damage to the supplied part.

  Further, in the present embodiment, the ECU 51 stores the plurality of hydraulic pressure values P1, P2, and P3 stored in the ROM 51b in accordance with the amount of oil stored in the oil pan 31, and is stored in the oil pan 31. The first hydraulic pressure determination value Pa and the second hydraulic pressure determination value Pb can be set based on the remaining amount of oil, and the first hydraulic pressure determination value Pb can be set with respect to the hydraulic pressure determination value that has more margin than the damage avoidance hydraulic pressure determination value Pp when the hydraulic pressure decreases. The upper limit rotational speed Na of 1 and the second upper rotational speed Nb can be set.

  In the present embodiment, the ECU 51 drives the drive motor 43 and opens the throttle valve 42 on the condition that the hydraulic pressure is less than the first hydraulic pressure determination value Pa or the second hydraulic pressure determination value Pb. By controlling to the closed side, the increase in the engine speed is limited, so that it is possible to prevent early occurrence of burning of the portion to be supplied when the hydraulic pressure is abnormal.

  Further, in the present embodiment, the ECU 51 issues a warning by the warning lamp 55 on condition that the hydraulic pressure discharged from the oil pump 33 is less than the first hydraulic pressure determination value Pa or the second hydraulic pressure determination value Pb. Therefore, it is possible to warn the driver that the oil stored in the oil pan 31 is insufficient. Therefore, it is possible to prompt the driver to check the oil in the oil pan 31 or to replenish the oil pan 31 with oil.

  In the present embodiment, the ECU 51 sets the hydraulic pressure values Pf, P1, P2, and P3 based on the engine speed, the temperature and oil pressure of the oil discharged from the oil pump 33, and therefore the engine speed and the oil temperature. It is possible to set optimum hydraulic pressure values Pf, P1, P2, and P3 according to the above, and to detect an abnormal hydraulic pressure with high accuracy.

  Further, in the present embodiment, a plurality of hydraulic pressure levels are set based on the engine speed, the oil temperature, and the hydraulic pressure, but a water temperature may be used as a parameter instead of the oil temperature. In this case, the ECU 51 may acquire water temperature information from a water temperature sensor that detects the temperature of the cooling water that cools the engine 2.

  As described above, the control device for an internal combustion engine according to the present invention can widen the range in which normal traveling can be continued according to the normal rotational speed range, and can suppress the driver from feeling uncomfortable. And is useful as a control device for an internal combustion engine that limits an increase in the rotational speed of the internal combustion engine when an abnormality is detected in the hydraulic pressure supplied from the oil pump to the supply site.

2 Engine (Internal combustion engine)
3 Transmission 5 Control device 10 Piston (supplied part)
11 VVT (supplied part)
12a Crank journal (supplied part)
12b Crank pin (supplied part)
16 Connecting rod (part to be supplied)
31 Oil pan (oil storage means)
33 Oil pump 37 Oil jet (part to be supplied)
38 Rush adjuster (supplied part)
41 Intake pipe 42 Throttle valve 43 Drive motor (drive member)
51 ECU (engine control means, hydraulic pressure level setting unit, upper limit rotation speed setting unit, first hydraulic pressure determination value setting unit, second hydraulic pressure determination setting unit)
55 Warning lamp (Warning means)
Pp Damage avoidance hydraulic pressure determination value Pa First hydraulic pressure determination value Pb First hydraulic pressure determination value Na First upper limit rotation speed Nb Second upper limit rotation speed Pf Normal level hydraulic pressure values P1, P2, P3 (with respect to Pf) (Hydraulic values of multiple hydraulic levels where the hydraulic pressure drops at a constant rate)
Pa1 specific oil pressure value (first specific oil pressure value)
Pa2 specific oil pressure value (third specific oil pressure value)
Pb1 specific oil pressure value (second specific oil pressure value)
Pb2 specific hydraulic pressure value (fourth specific hydraulic pressure value)

Claims (7)

An increase in the number of revolutions of the internal combustion engine is provided in an internal combustion engine having an oil pump that supplies oil stored in the oil storage means to a supplied part, and when an abnormality is detected in the hydraulic pressure supplied from the oil pump to the supplied part. A control device for an internal combustion engine provided with engine control means for limiting
The engine control means is set with a damage avoidance hydraulic pressure judgment value for hydraulic pressure abnormality judgment of a magnitude that does not damage the supplied part so as to increase according to the rotational speed of the internal combustion engine,
When the normal rotation speed is set in the low rotation speed range, the hydraulic pressure abnormality larger than the damage avoidance hydraulic pressure determination value so as to increase according to the rotation speed of the internal combustion engine at least in the low rotation speed range of the internal combustion engine A first hydraulic pressure determination value for determination is set, and a first upper limit rotational speed that restricts an increase in the rotational speed of the internal combustion engine is set, and the hydraulic pressure discharged from the oil pump is determined as the first hydraulic pressure determination. Limiting the rotational speed of the internal combustion engine to the first upper limit rotational speed on condition that the value is less than the value;
When the normal rotation speed is set in a high rotation speed range, a second hydraulic pressure determination for determining a hydraulic pressure greater than the first hydraulic pressure determination value so as to increase according to the rotation speed of the internal combustion engine. A value is set, a second upper limit rotational speed is set on a higher rotational speed range side than the first upper limit rotational speed, and the hydraulic pressure discharged from the oil pump becomes less than the second hydraulic pressure determination value. The control device for the internal combustion engine is characterized in that the rotational speed of the internal combustion engine is limited to the second upper limit rotational speed on the condition. When the normal engine speed is set to a low engine speed range, the engine control means is configured to set the first upper limit at a higher engine speed than the first upper engine speed determination value associated with the first hydraulic pressure determination value. The engine speed is set to a lower oil pressure side than the damage avoidance oil pressure determination value, and the engine speed is limited to the first upper limit engine speed on condition that the engine speed is less than the damage avoidance oil pressure determination value. ,
When the normal rotational speed is set in the high rotational speed range, the damage is avoided from the second upper limit rotational speed at a rotational speed higher than the second upper limit rotational speed associated with the second hydraulic pressure determination value. The rotational speed of the internal combustion engine is limited to the second upper limit rotational speed on the condition that the hydraulic pressure determination value is set to a lower hydraulic pressure side and is less than the damage avoidance hydraulic pressure determination value. Item 2. A control device for an internal combustion engine according to Item 1. The engine control means has a characteristic that the hydraulic pressure increases as the rotational speed of the internal combustion engine increases, and the hydraulic pressure supplied from the oil pump to the supplied part is a normal level hydraulic pressure value and the normal level hydraulic pressure A hydraulic pressure level setting section for setting hydraulic pressure values of a plurality of hydraulic pressure levels at which the hydraulic pressure decreases at a constant rate relative to the value
An upper limit rotational speed setting unit for setting the first upper limit rotational speed or the second upper limit rotational speed;
When the normal rotation speed is set in a low rotation speed range, a first specific hydraulic pressure value that matches the first upper limit rotation speed is determined from the damage avoidance hydraulic pressure determination values, and the plurality of hydraulic pressure levels are determined. A first hydraulic pressure determination value setting unit that sets, as the first hydraulic pressure determination value, a hydraulic pressure level having a third specific hydraulic pressure value that matches the first specific hydraulic pressure value;
When the normal rotation speed is set in a high rotation speed range, a second specific hydraulic pressure value that matches the second upper limit rotation speed is determined from the damage avoidance hydraulic pressure determination value, A second hydraulic pressure determination value setting unit that sets, as the second hydraulic pressure determination value, a hydraulic pressure level that has a fourth specific hydraulic pressure value that matches the second hydraulic pressure determination value from among the hydraulic pressure levels. The control apparatus for an internal combustion engine according to claim 1 or 2, wherein the control apparatus is an internal combustion engine.   The control apparatus for an internal combustion engine according to claim 3, wherein the plurality of hydraulic pressure levels set in the hydraulic pressure level setting unit correspond to the amount of oil stored in the oil storage means. The internal combustion engine includes an intake pipe that introduces intake air into the internal combustion engine, a throttle valve that is provided in the intake pipe and adjusts an intake air amount supplied to the internal combustion engine, and a drive member that drives the throttle valve And comprising
The engine control means drives the drive member on the condition that the hydraulic pressure discharged from the oil pump is less than the first hydraulic pressure determination value when the normal rotational speed is in a low rotational speed range. By controlling the opening of the throttle valve to the closed side, the increase in the rotational speed of the internal combustion engine is limited,
When the normal rotational speed is in the high rotational speed range, the drive member is driven to open the throttle valve on condition that the hydraulic pressure discharged from the oil pump is less than the second hydraulic pressure determination value. The control device for an internal combustion engine according to any one of claims 1 to 4, wherein an increase in the rotational speed of the internal combustion engine is limited by controlling the degree to a closed side. Warning means for warning that the hydraulic pressure is abnormal based on an abnormal signal output from the engine control means;
The engine control means outputs a warning signal to the warning means on condition that the hydraulic pressure discharged from the oil pump is less than the first hydraulic pressure judgment value when the normal rotational speed is in a low rotational speed range. Output
When the normal rotation speed is in a high rotation speed range, a warning signal is output to the warning means on condition that the hydraulic pressure discharged from the oil pump is less than the second hydraulic pressure determination value. The control device for an internal combustion engine according to any one of claims 1 to 5.   The engine control means sets the hydraulic pressure level based on the rotational speed of the internal combustion engine, the temperature of oil discharged from the oil pump, and the hydraulic pressure discharged from the oil pump. The control apparatus for an internal combustion engine according to any one of claims 3 to 6.

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