JP6354717B2 - Engine control device - Google Patents

Description

  The technology disclosed herein relates to an engine control device.

  2. Description of the Related Art Conventionally, a technique for controlling the oil pressure of an oil supply passage to which oil is supplied from an engine oil pump is known.

  For example, Patent Document 1 discloses a technique for controlling the oil pressure in the oil supply passage based on the highest required oil pressure from a plurality of hydraulic actuators. When the deviation between the actual hydraulic pressure and the target hydraulic pressure continues to be larger than a predetermined threshold, the control device according to Patent Document 1 limits the engine operation so that the high rotation side of the engine is not used. ing.

JP 2014-45288 A

  In a state where the oil pressure of the oil supply passage is uncontrollable, it is preferable to limit the operation of the engine as in the technique of Patent Document 1 in consideration of poor lubrication, oil leakage, or malfunction of the hydraulic actuator. However, if the operation of the engine is restricted more than necessary, the traveling performance of the vehicle may be impaired.

  The technology disclosed herein has been made in view of such a point, and an object thereof is to secure the traveling performance of the vehicle while solving the problems caused by the poor control of the hydraulic pressure.

The technique disclosed here, the oil pressure sensor for detecting the oil pressure of the oil supply passage that the oil from the variable displacement oil pump driven by the engine is supplied, the variable capacitance to adjust the capacity of the variable capacity oil pump The engine control device includes a control valve that adjusts the flow rate of oil supplied to the oil pump, an oil temperature sensor that detects the oil temperature of the oil supply passage, and an operation control unit that controls the operation of the engine. . Then, the operation control unit has a predetermined upper limit rotation speed when the oil pressure abnormality detected by the oil pressure sensor is out of a controllable range via the control valve. The operating state of the engine is limited to a range not exceeding, and the upper limit rotational speed is corrected according to the oil temperature detected by the oil temperature sensor.

  According to this configuration, a hydraulic pressure abnormality in which the oil pressure in the oil supply passage is outside the controllable range may occur due to a malfunction of the variable capacity oil pump, the control valve, or the hydraulic pressure sensor.

  However, when the oil pressure is abnormal, the engine operating state is limited to a range where the engine speed does not exceed the upper limit speed, so that the oil pressure, such as oil leakage, malfunction of the hydraulic actuator, or poor lubrication of the lubrication part, etc. Problems caused by poor control are suppressed.

  Specifically, the capacity of the variable capacity oil pump is adjusted according to the flow rate of oil supplied from the control valve. However, if the displacement of the variable displacement oil pump becomes unadjustable due to some factor, the discharge amount of the variable displacement oil pump increases as the engine speed increases, and the oil pressure in the oil supply passage increases. Therefore, when the oil pressure is abnormal, the engine operating state is limited to a range where the engine speed does not exceed the upper limit speed, thereby limiting the discharge amount of the oil pump and preventing the oil pressure in the oil supply passage from becoming too high. The As a result, oil leakage and malfunction of the hydraulic actuator are suppressed. On the other hand, by suppressing the rotational speed of the engine, the sliding speed of the sliding member such as the crankshaft can also be suppressed. Therefore, the hydraulic pressure required for the sliding part such as a bearing is also reduced. That is, even if the oil pressure in the oil supply passage becomes low due to an oil pressure abnormality, the sliding speed of the sliding member is limited, so that poor lubrication in the lubricating portion is suppressed.

  On the premise of such a configuration, the upper limit rotational speed when the engine operating state is limited is corrected according to the oil temperature detected by the oil temperature sensor. As a result, the traveling performance of the vehicle can be ensured while solving the problems caused by the above-described hydraulic control failure.

  Specifically, the viscosity of the oil changes depending on the oil temperature. Along with this, the degree of malfunction caused by poor hydraulic control also changes according to the oil temperature. For example, since the discharge efficiency of the oil pump becomes higher as the oil temperature is lower, the discharge amount of the oil pump, and hence the hydraulic pressure of the oil discharged from the oil pump becomes higher as the oil temperature is lower. That is, oil leakage and malfunction of the hydraulic actuator are worsened as the oil temperature is lower. On the other hand, since the oil film in the lubrication part is more easily secured as the oil temperature is lower, poor lubrication is suppressed as the oil temperature is lowered. Therefore, the operating range of the engine that can be operated without causing problems due to poor control of the hydraulic pressure changes according to the oil temperature. Therefore, by correcting the upper limit rotational speed when limiting the engine operating state described above according to the oil temperature, the operable range of the engine under the limitation can be expanded according to the oil temperature. As a result, the traveling performance of the vehicle can be ensured while solving the problems caused by the poor control of the hydraulic pressure.

  Further, the operation control unit is configured so that the engine rotation speed does not exceed a predetermined first upper limit rotation speed when the oil pressure in the oil supply passage exceeds a controllable range and is in a high hydraulic pressure abnormality. The first upper limit rotational speed may be corrected according to the oil temperature detected by the oil temperature sensor.

  According to this configuration, when the oil pressure abnormality is a high oil pressure abnormality in which the oil pressure in the oil supply passage exceeds the controllable range, the engine rotation speed does not exceed the first upper limit rotation speed. The first operating speed is corrected according to the oil temperature. That is, the upper limit rotational speed when the engine operating state is limited when the high hydraulic pressure is abnormal is the first upper limit rotational speed.

  Further, the operation control unit is configured so that the engine rotation speed does not exceed a predetermined second upper limit rotation speed when the oil pressure in the oil supply passage is lower than the controllable range and becomes low. The second upper limit rotational speed may be corrected according to the oil temperature detected by the oil temperature sensor.

  According to this configuration, when the oil pressure abnormality is a low oil pressure abnormality in which the oil pressure in the oil supply passage is lower than the controllable range, the engine rotation speed does not exceed the second upper limit rotation speed. And the second upper limit rotation speed is corrected according to the oil temperature. That is, the upper limit rotation speed when the engine operating state is limited when the low hydraulic pressure is abnormal is the second upper limit rotation speed.

  Further, the operation control unit is configured such that when the oil pressure in the oil supply passage is below the controllable range and less than a predetermined lower limit oil pressure, a third upper limit rotation speed in which the engine rotation speed is smaller than the second upper limit rotation speed. The engine operating state may be limited to a range in which the engine load does not exceed the predetermined upper limit load.

  According to this configuration, when the hydraulic pressure is less than the lower limit hydraulic pressure in the low hydraulic pressure abnormality, the operating state of the engine is further limited. Specifically, the operating state of the engine is limited to a range in which the engine rotation speed does not exceed the third upper limit rotation speed smaller than the second upper limit rotation speed and the engine load does not exceed the upper limit load. That is, when the hydraulic pressure is relatively high (ie, when the hydraulic pressure is equal to or higher than the lower limit hydraulic pressure) in the low hydraulic pressure abnormality, the engine operating state is limited to a range in which the engine speed does not exceed the second upper limit speed. On the other hand, when the hydraulic pressure is relatively low (ie, when the hydraulic pressure is less than the lower limit hydraulic pressure) in the low hydraulic pressure abnormality, the engine speed is further limited and the engine load is also limited. Thus, when the oil pressure is relatively low in the low oil pressure abnormality, both the engine speed and the load are limited, and the upper limit speed at that time is also lower than the second upper limit speed, thereby causing poor lubrication. This can prevent the engine from being damaged.

  According to the engine control apparatus, it is possible to ensure the traveling performance of the vehicle while solving the problems caused by the poor control of the hydraulic pressure.

1 is a schematic cross-sectional view of an engine cut along a plane including an axis of a cylinder. It is a longitudinal cross-sectional view of a crankshaft. It is sectional drawing which shows schematic structure of a variable valve timing mechanism. It is a hydraulic circuit diagram of an oil supply apparatus. It is a functional block diagram of a controller. It is a base oil pressure map. It is a demand oil pressure map of an oil jet. It is a request | requirement hydraulic pressure map of the exhaust side VVT. It is a block diagram of discharge amount control of the oil pump by a controller. It is a part of flowchart of the discharge amount control of an oil pump, and the operation control of an engine. It is the remaining part of the flowchart of discharge amount control of an oil pump and engine operation control. It is explanatory drawing which shows the driving | operation area | region of the engine in 1st fail safe mode. It is explanatory drawing which shows the driving | operation area | region of the engine in the 2nd fail safe mode and retraction | saving mode. It is explanatory drawing which shows the relationship between the hydraulic pressure characteristic of an oil pump, and the limit hydraulic pressure of an oil supply apparatus.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of engine 100 cut along a plane including the axis of the cylinder. In the present specification, for convenience of explanation, the axial direction of the cylinder is referred to as the vertical direction, and the cylinder row direction is referred to as the front-rear direction.

  The engine 100 is an in-line four-cylinder engine in which four cylinders are arranged in a predetermined cylinder row direction. The engine 100 includes a cylinder head 1, a cylinder block 2 attached to the cylinder head 1, and an oil pan 3 attached to the cylinder block 2.

  The cylinder block 2 has an upper block 21 and a lower block 22. The lower block 22 is attached to the lower surface of the upper block 21. An oil pan 3 is attached to the lower surface of the lower block 22.

  In the upper block 21, four cylinder bores 23 corresponding to the four cylinders are formed side by side in the cylinder row direction (only one cylinder bore 23 is shown in FIG. 1). The cylinder bore 23 is formed in the upper part of the upper block 21, and the lower part of the upper block 21 defines a part of the crank chamber. A piston 24 is inserted into the cylinder bore 23. The piston 24 is connected to the crankshaft 26 via a connecting rod 25. A combustion chamber 27 is defined by the cylinder bore 23, the piston 24, and the cylinder head 1. The four cylinder bores 23 correspond to a first cylinder, a second cylinder, a third cylinder, and a fourth cylinder in order from the front side.

  The cylinder head 1 is provided with an intake port 11 and an exhaust port 12 that open to the combustion chamber 27, and the intake port 11 is provided with an intake valve 13 that opens and closes the intake port 11. The exhaust port 12 is provided with an exhaust valve 14 that opens and closes the exhaust port 12. The intake valve 13 and the exhaust valve 14 are driven by cam portions 41a and 42a provided on the cam shafts 41 and 42, respectively.

  Specifically, the intake valve 13 and the exhaust valve 14 are urged in the closing direction (upward in FIG. 1) by the valve springs 15 and 16. Swing arms 43 and 44 are interposed between the intake valve 13 and the exhaust valve 14 and the cam portions 41a and 42a, respectively. One end portions of the swing arms 43 and 44 are supported by hydraulic lash adjusters (hereinafter referred to as “HLA”) 45 and 46, respectively. The swing arms 43 and 44 swing around the one end portions supported by the HLA 45 and 46 as the cam followers 43a and 44a provided at substantially central portions thereof are pushed by the cam portions 41a and 42a, respectively. By swinging in this way, the swing arms 43 and 44 move the intake valve 13 and the exhaust valve 14 at the other end in the opening direction (downward in FIG. 1) against the urging force of the valve springs 15 and 16, respectively. Let The HLA 45 and 46 automatically adjust the valve clearance to zero by hydraulic pressure.

  The HLA 45 and 46 provided in the first cylinder and the fourth cylinder are provided with valve stop mechanisms that stop the operations of the intake valve 13 and the exhaust valve 14, respectively. Hereinafter, when HLA is distinguished by the presence or absence of a valve stop mechanism, the HLA 45 and 46 having the valve stop mechanism are referred to as HLA 45a and 46a, and the HLA 45 and 46 having no valve stop mechanism are referred to as HLA 45b and 46b. Called. The engine 100 operates all the intake valves 13 and the exhaust valves 14 of the first to fourth cylinders during all cylinder operation, while the intake valves 13 and the exhaust valves 14 of the first and fourth cylinders operate during the reduced cylinder operation. The operation is stopped, and the intake valve 13 and the exhaust valve 14 of the second and third cylinders are operated.

  In portions corresponding to the first and fourth cylinders of the cylinder head 1, mounting holes for mounting the HLA 45a and 46a are formed. The HLA 45a and 46a are mounted in the mounting hole. The cylinder head 1 is formed with an oil supply passage communicating with the mounting hole. Oil is supplied to the HLA 45a and 46a through this oil supply passage.

  A cam cap 47 is attached to the upper part of the cylinder head 1. The cam shafts 41 and 42 are rotatably supported by the cylinder head 1 and the cam cap 47.

  An intake side oil shower 48 is provided above the intake side camshaft 41, and an exhaust side oil shower 49 is provided above the exhaust side camshaft 42. The intake-side oil shower 48 and the exhaust-side oil shower 49 are configured to drop oil on contact portions between the cam portions 41a and 42a and the cam followers 43a and 44a of the swing arms 43 and 44.

  The engine 100 is also provided with a variable valve timing mechanism (hereinafter referred to as “VVT”) that changes the valve characteristics of the intake valve 13 and the exhaust valve 14. The intake side VVT is an electric type, and the exhaust side VVT 18 is a hydraulic type.

  The upper block 21 has a first side wall 21 a located on the intake side with respect to the four cylinder bores 23, a second side wall 21 b located on the exhaust side with respect to the four cylinder bores 23, and a front side relative to the frontmost cylinder bore 23. A plurality of vertical walls extending in the vertical direction at a portion between a front wall (not shown) positioned, a rear wall (not shown) positioned rearward of the rearmost cylinder bore 23, and two adjacent cylinder bores 23 Wall 21c.

  The lower block 22 corresponds to the first side wall 21a of the upper block 21, and corresponds to the first side wall 22a located on the intake side, and the second side wall 22b located on the exhaust side corresponding to the second side wall 21b of the upper block 21. The front wall corresponding to the front wall of the upper block 21 (not shown), the rear wall corresponding to the rear wall of the upper block 21 and not shown, and the upper block 21 It has the some vertical wall 22c corresponding to the vertical wall 21c. The upper block 21 and the lower block 22 are bolted.

  There is a crankshaft 26 between the front wall of the upper block 21 and the front wall of the lower block 22, between the rear wall of the upper block 21 and the rear wall of the lower block 22, and between the vertical wall 21c and the vertical wall 22c. The bearing part 28 which supports is provided.

  Hereinafter, the bearing portion 28 between the vertical wall 21c and the vertical wall 22c will be described with reference to FIG. FIG. 2 is a cross-sectional view of the vertical wall 21c of the upper block 21 and the vertical wall 22c of the lower block 22 located at the center in the cylinder row direction. Similar bearings 28 are provided between the front wall of the upper block 21 and the front wall of the lower block 22 and between the rear wall of the upper block 21 and the rear wall of the lower block 22. When distinguishing each bearing part 28, it calls the 1st bearing part 28A, the 2nd bearing part 28B, the 3rd bearing part 28C, the 4th bearing part 28D, and the 5th bearing part 28E sequentially from the front side.

  The bearing portion 28 is provided between two bolt fastening locations. Specifically, the bearing portion 28 is disposed between the pair of screw holes 21f and the bolt insertion holes 22f. The bearing portion 28 has a cylindrical bearing metal 29. A semicircular cutout is formed at each joint between the vertical wall 21c and the vertical wall 22c. The bearing metal 29 has a divided structure composed of a first semicircular portion 29a and a second semicircular portion 29b, and the first semicircular portion 29a is attached to a notch portion of the vertical wall 21c, and the second semicircular portion is provided. The portion 29b is attached to the cutout portion of the vertical wall 22c. By combining the vertical wall 21c and the vertical wall 22c, the first semicircular portion 29a and the second semicircular portion 29b are combined to form a cylindrical shape. An oil groove 29c extending in the circumferential direction is formed on the inner peripheral surface of the first semicircular portion 29a. In addition, the first semicircular portion 29a is formed with a connecting passage 29d having one end opened to the outer peripheral surface of the first semicircular portion 29a and the other end opened to the oil groove 29c. An oil supply passage is formed in the upper block 21, and oil is supplied to the outer peripheral surface of the first semicircular portion 29a through the oil supply passage. The communication path 29d is disposed at a position communicating with the oil supply path. As a result, the oil supplied from the oil supply passage flows into the oil groove 29c through the communication passage 29d.

  Although not shown, a chain cover is attached to the front wall of the cylinder block 2. A drive sprocket provided on the crankshaft 26, a timing chain wound around the drive sprocket, a chain tensioner for applying tension to the timing chain, and the like are disposed inside the chain cover.

  Next, the exhaust side VVT 18 will be described in detail with reference to FIG.

  The exhaust side VVT 18 includes a substantially annular housing 18a and a rotor 18b accommodated in the housing 18a. The housing 18a is connected to a cam pulley 18c that rotates in synchronization with the crankshaft 26 so as to be integrally rotatable. The rotor 18b is connected to a camshaft 41 that opens and closes the intake valve 13 so as to be integrally rotatable. The rotor 18b is provided with a vane 18d that slides with the inner peripheral surface of the housing 18a. A plurality of retarded hydraulic chambers 18e and advanced hydraulic chambers 18f defined by the inner peripheral surface of the housing 18a, the vanes 18d and the main body of the rotor 18b are formed in the housing 18a. Oil is supplied to the retard hydraulic chamber 18e and the advance hydraulic chamber 18f. When the hydraulic pressure in the retarded hydraulic chamber 18e is high, the rotor 18b rotates in the opposite direction with respect to the rotation direction of the housing 18a. That is, the camshaft 41 rotates in the opposite direction with respect to the cam pulley 18c, and the valve opening timing of the intake valve 13 is delayed. On the other hand, when the hydraulic pressure in the advance hydraulic chamber 18f is high, the rotor 18b rotates in the same direction with respect to the rotation direction of the housing 18a. That is, the camshaft 41 rotates in the same direction with respect to the cam pulley 18c, and the valve opening timing of the intake valve 13 is advanced.

  Next, the oil supply apparatus 200 will be described with reference to FIG. FIG. 4 shows a hydraulic circuit diagram of the oil supply device 200.

  The oil supply apparatus 200 includes a variable capacity oil pump 81 that is rotationally driven by the crankshaft 26, and an oil supply passage 5 that is connected to the oil pump 81 and through which oil flows. Oil pump 81 is an auxiliary machine driven by engine 100.

  The oil pump 81 is a known variable displacement oil pump and is driven by the crankshaft 26. The oil pump 81 is attached to the lower surface of the lower block 22 and is housed in the oil pan 3. Specifically, the oil pump 81 includes a drive shaft 81a that is rotationally driven by the crankshaft 26, a rotor 81b that is coupled to the drive shaft 81a, and a plurality of vanes 81c that are capable of moving forward and backward in the radial direction from the rotor 81b. The cam ring 81d configured to accommodate the rotor 81b and the vane 81c and adjust the amount of eccentricity with respect to the rotation center of the rotor 81b, and bias the cam ring 81d in a direction in which the amount of eccentricity with respect to the rotation center of the rotor 81b increases. It includes a spring 81e, a ring member 81f disposed inside the rotor 81b, and a housing 81g that houses the rotor 81b, vane 81c, cam ring 81d, spring 81e, and ring member 81f.

  Although not shown, one end of the drive shaft 81a protrudes outward from the housing 81g, and a driven sprocket is connected to the one end. A timing chain is wound around the driven sprocket. This timing chain is also wound around the drive sprocket of the crankshaft 26. Thus, the rotor 81b is rotationally driven by the crankshaft 26 via the timing chain.

  When the rotor 81b rotates, each vane 81c slides on the inner peripheral surface of the cam ring 81d. Accordingly, the pump chamber (hydraulic oil chamber) 81i is defined by the rotor 81b, the two adjacent vanes 81c, the cam ring 81d, and the housing 81g.

  The housing 81g is formed with a suction port 81j through which oil is sucked into the pump chamber 81i and a discharge port 81k through which oil is discharged from the pump chamber 81i. An oil strainer 81l is connected to the suction port 81j. The oil strainer 81 l is immersed in the oil stored in the oil pan 3. That is, the oil stored in the oil pan 3 is sucked into the pump chamber 81i from the suction port 81j through the oil strainer 81l. On the other hand, the oil supply path 5 is connected to the discharge port 81k. That is, the oil boosted by the oil pump 81 is discharged from the discharge port 81k to the oil supply passage 5.

  The cam ring 81d is supported by the housing 81g so as to swing around a predetermined fulcrum. The spring 81e biases the cam ring 81d toward one side around the fulcrum. A pressure chamber 81m is defined between the cam ring 81d and the housing 81g. The pressure chamber 81m is configured to be supplied with oil from the outside. The oil pressure in the oil pressure chamber 81m acts on the cam ring 81d. Therefore, the cam ring 81d swings according to the balance between the biasing force of the spring 81e and the hydraulic pressure of the pressure chamber 81m, and the amount of eccentricity of the cam ring 81d with respect to the rotation center of the rotor 81b is determined. The capacity of the oil pump 81 changes according to the amount of eccentricity of the cam ring 81d, and the amount of oil discharged changes.

  Oil is supplied to the pressure chamber 81m from an oil control valve 84 described later. That is, the capacity of the oil pump 81 is controlled by the oil control valve 84. The oil pump 81 and the oil control valve 84 are an example of a hydraulic control device.

  The oil supply path 5 is formed by a pipe and a flow path formed in the cylinder head 1 and the cylinder block 2. The oil supply passage 5 includes a main gallery 50 extending in the cylinder row direction in the cylinder block 2, a first communication passage 51 connecting the oil pump 81 and the main gallery 50, and a second communication passage extending from the main gallery 50 to the cylinder head 1. 52, a third communication passage 53 extending in a substantially horizontal direction between the intake side and the exhaust side in the cylinder head 1, a control oil supply passage 54 branched from the first communication passage 51, and a branch from the third communication passage 53 And first to fifth oil supply passages 55 to 59.

  The first communication path 51 is connected to the discharge port 81 k of the oil pump 81. In the first communication passage 51, an oil filter 82 and an oil cooler 83 are provided in order from the oil pump 81 side. That is, the oil discharged from the oil pump 81 to the first communication passage 51 is filtered by the oil filter 82, the oil temperature is adjusted by the oil cooler 83, and then flows into the main gallery 50.

  In the main gallery 50, an oil jet 71 that injects oil to the back side of the four pistons 24, a bearing metal 29 of five bearing portions 28 that rotatably supports the crankshaft 26, and four connecting rods 25 rotate. A bearing metal 72 disposed on a freely connected crank pin, an oil supply part 73 that supplies oil to the hydraulic chain tensioner, an oil jet 74 that injects oil to the timing chain, and oil that circulates through the main gallery 50 A hydraulic pressure sensor 50a for detecting the hydraulic pressure is connected. The hydraulic pressure sensor 50a is an example of a hydraulic pressure detection unit. Oil is always supplied to the main gallery 50. The oil jet 71 has a check valve and a nozzle, and when a hydraulic pressure of a predetermined value or more acts, the check valve opens to inject oil from the nozzle.

  The control oil supply passage 54 branches from the main gallery 50 and is connected to the pressure chamber 81 m of the oil pump 81 via the oil control valve 84. An oil filter 54 a is provided in the control oil supply passage 54. Part of the oil in the main gallery 50 passes through the control oil supply passage 54, adjusts the oil pressure by the oil control valve 84, and then flows into the pressure chamber 81 m of the oil pump 81. That is, the pressure of the pressure chamber 81 m is adjusted by the oil control valve 84.

  The oil control valve 84 is a linear solenoid valve. The oil control valve 84 adjusts the flow rate of oil supplied to the pressure chamber 81m according to the duty ratio of the input control signal.

  The second communication path 52 allows the main gallery 50 and the third communication path 53 to communicate with each other. Oil flowing through the main gallery 50 flows into the third communication path 53 through the second communication path 52. The oil flowing into the third communication path 53 is distributed to the intake side and the exhaust side of the cylinder head 1 through the third communication path 53.

  The first oil supply passage 55 includes an oil supply portion 91 for a bearing metal that supports the cam journal of the intake camshaft 41, an oil supply portion 92 for a thrust bearing of the intake camshaft 41, and an HLA 45a with a valve stop mechanism. The pivot mechanism 45c, the HLA 45b without a valve stop mechanism, the oil shower 48 on the intake side, and the oil supply portion 93 of the sliding portion of the intake side VVT are connected.

  The second oil supply passage 56 includes a bearing metal oil supply portion 94 that supports the cam journal of the exhaust camshaft 42, a thrust bearing oil supply portion 95 of the exhaust camshaft 42, and an HLA 46a with a valve stop mechanism. The pivot mechanism 46c, the HLA 46b without a valve stop mechanism, and the oil shower 49 on the exhaust side are connected.

  The third oil supply passage 57 is connected to the retard hydraulic chamber 18e and the advance hydraulic chamber 18f of the exhaust side VVT 18 via the first direction switching valve 96. The third oil supply passage 57 is connected to an oil supply portion 94 located at the forefront portion of the oil supply portion 94 of the bearing metal of the camshaft 42 on the exhaust side. An oil filter 57 a is connected to the upstream side of the first direction switching valve 96 in the third oil supply passage 57. The flow rate of oil supplied to the retard hydraulic chamber 18e and the advance hydraulic chamber 18f is adjusted by the first direction switching valve 96.

  The fourth oil supply path 58 is connected to the valve stop mechanism 45d of the HLA 45a with the valve stop mechanism of the first cylinder and the valve stop mechanism 46d of the HLA 46a with the valve stop mechanism via the second direction switching valve 97. An oil filter 58 a is connected to the upstream side of the second direction switching valve 97 in the fourth oil supply path 58. The oil supply to the valve stop mechanism 45d and the valve stop mechanism 46d of the first cylinder is controlled by the second direction switching valve 97.

  The fifth oil supply passage 59 is connected via a third direction switching valve 98 to the valve stop mechanism 45d of the HLA 45a with a valve stop mechanism of the fourth cylinder and the valve stop mechanism 46d of the HLA 46a with a valve stop mechanism. An oil filter 59 a is connected to the upstream side of the third direction switching valve 98 in the fifth oil supply passage 59. The third direction switching valve 98 controls oil supply to the valve stop mechanism 45d and the valve stop mechanism 46d of the fourth cylinder.

  The oil supplied to each part of the engine 100 is dropped into the oil pan 3 through a drain oil passage (not shown) and is recirculated by the oil pump 81.

  In the above, the exhaust side VVT 18, the valve stop mechanism 45d, the valve stop mechanism 46d, the oil jet 71, and the oil jet 74 correspond to the hydraulic actuator. Bearing metal 29, intake side oil shower 48, exhaust side oil shower 49, bearing metal 72, bearing metal supporting cam journal of camshaft 41, thrust bearing of camshaft 41, bearing metal supporting cam journal of camshaft 42 The thrust bearing of the camshaft 42 and the sliding portion of the intake side VVT correspond to the lubricating portion.

  Engine 100 is controlled by controller 60. The controller 60 has a processor and a memory, and receives detection results from various sensors that detect the operating state of the engine 100. For example, the controller 60 includes an oil pressure sensor 50 a, a crank angle sensor 61 that detects the rotation angle of the crankshaft 26, an airflow sensor 62 that detects the amount of air taken in by the engine 100, an oil temperature sensor 63, and camshafts 41 and 42. A cam angle sensor 64 that detects the rotational phase and a water temperature sensor 65 that detects the temperature of the cooling water of the engine 100 are connected. The controller 60 obtains the engine rotation speed based on the detection signal from the crank angle sensor 61, obtains the engine load based on the detection signal from the airflow sensor 62, and determines the intake side VVT and exhaust gas based on the detection signal from the cam angle sensor 64. The operating angle of the side VVT 18 is obtained. The controller 60 is an example of a control device.

  The controller 60 controls the engine 100 and the oil supply device 200. More specifically, as shown in FIG. 5, the controller 60 includes a hydraulic control unit 601 that controls the oil supply device 200 and an operation control unit 602 that controls the operation of the engine 100.

  The hydraulic control unit 601 determines the operating state of the engine 100 based on various detection results, and the oil control valve 84, the first direction switching valve 96, the second direction switching valve 97, and the third direction according to the determined operating state. The switching valve 98 is controlled. For example, the hydraulic control unit 601 controls the discharge amount of the oil pump 81 according to the operating state of the engine 100. Specifically, the hydraulic control unit 601 sets a target hydraulic pressure according to the operating state of the engine 100, and the oil pump 81 via the oil control valve 84 so that the hydraulic pressure detected by the hydraulic sensor 50a becomes the target hydraulic pressure. To control.

  First, setting of the target hydraulic pressure will be described.

  The oil supply device 200 supplies oil to a plurality of hydraulic actuators by one oil pump 81. The hydraulic pressure required by each hydraulic actuator varies depending on the operating state of engine 100. Therefore, in order to obtain a hydraulic pressure that is required by all the hydraulic actuators in all operating states of the engine 100, the hydraulic control unit 601 determines the maximum required hydraulic pressure of each hydraulic actuator for each operating state of the engine 100. It is necessary to set the target oil pressure or a maximum oil pressure. In the present embodiment, the exhaust side VVT 18, the valve stop mechanisms 45d and 46d, and the oil jet 71 are hydraulic actuators having a relatively large required oil pressure. Therefore, if the target oil pressure is set so as to satisfy these required oil pressures, the required oil pressure of the hydraulic actuator having a relatively small required oil pressure is naturally satisfied.

  Further, not only the hydraulic operation device but also the lubrication part such as the bearing metal 29 has a necessary oil pressure, and the required oil pressure of the lubrication part changes according to the operating state of the engine 100. If the required hydraulic pressure of the bearing metal 29 is relatively high in the lubricating portion and the required hydraulic pressure of the bearing metal 29 is satisfied, the required hydraulic pressure of the other lubricating portions is naturally satisfied.

  In the present embodiment, the hydraulic control unit 601 provides the required hydraulic pressure of the bearing metal 29 or a hydraulic pressure slightly higher than the required hydraulic pressure, which is necessary for basic operation of the engine 100 when the hydraulic actuator is not operating. The hydraulic pressure P1 is set. That is, the base hydraulic pressure P1 is a hydraulic pressure that satisfies the required hydraulic pressure of all the lubrication parts.

  The hydraulic control unit 601 compares the base hydraulic pressure P1 with the required hydraulic pressure P2 when each hydraulic actuator operates, and sets the highest hydraulic pressure as the target hydraulic pressure. Both the base oil pressure P1 and the required oil pressure P2 of the hydraulic operation device vary depending on the engine operating state (engine load, engine speed, oil temperature, etc.). Therefore, the hydraulic pressure control unit 601 includes a map in which the base hydraulic pressure P1 that is experimentally set in advance according to the engine load, the engine rotation speed, and the oil temperature is defined, and a map in which the required hydraulic pressure P2 of the hydraulic actuator is defined. Stored in memory.

  Specifically, FIG. 6 is a base hydraulic pressure map, FIG. 7 is a required hydraulic pressure map of the oil jet 71, and FIG. 8 is a required hydraulic pressure map of the exhaust side VVT 18. In each map, “hydraulic pressure” is stored for each “driving state” (not the engine operating state but the vehicle speed, accelerator pedal operating state, etc.), “load”, “oil temperature”, and “rotational speed”. . The unit of oil temperature is ° C., the unit of engine rotation speed is rpm, and the unit of oil pressure is kPa. 6 to 8 each extract a part of the map. Therefore, the hydraulic pressure can be set by further subdividing the operating state, load, oil temperature, and rotation speed. The oil pressure is set discretely according to the rotational speed and the like. Therefore, the oil pressure at a rotational speed or the like not set in the map can be obtained by linear interpolation of the oil pressure set in the map.

  The base oil pressure map of FIG. 6 stores a base oil pressure P1 set according to the engine speed at a predetermined oil temperature T after warming up.

  Since the base hydraulic pressure P1 is a hydraulic pressure necessary for the basic operation of the engine 100 when the hydraulic actuator is not operating, as shown in FIG. 6, special conditions (operation state, load, Oil temperature, rotation speed) are not specified. Since the lubrication of the bearing metal 29 and the like is required as the engine speed increases, the base oil pressure P1 is set to a higher value as the engine speed increases.

  In the middle rotation range, the base hydraulic pressure P1 is set to a substantially constant value (200 kPa in the example).

  The required oil pressure map of the oil jet 71 in FIG. 7 stores the required oil pressure P2 of the oil jet 71 set according to the engine operating state.

  As described above, the oil jet 71 has a check valve and a nozzle, and when a hydraulic pressure of a predetermined value or more acts, the check valve opens and injects oil from the nozzle. As shown in FIG. 7, the hydraulic pressure P2 is constant (350 kPa in the example) regardless of whether the engine speed (Va2> Va1) is different or the load (P1> P2) is different.

  The required hydraulic pressure map of the exhaust side VVT 18 in FIG. 8 stores the required hydraulic pressure P2 of the exhaust side VVT 18 set according to the engine operating state.

  Specifically, as shown in FIG. 8, the required oil pressure P2 of the exhaust side VVT 18 is set to a higher value as the engine speed increases, and set to a higher value as the oil temperature (Ta1> Ta2> Ta3) decreases. Is done.

  Next, with reference to FIG. 9, the flow of signals in the discharge amount control of the oil pump 81 will be described.

  The oil pressure control unit 601 obtains the base oil pressure P1 by comparing the engine speed and the oil temperature detected by the various sensors with the base oil pressure map. In addition, the hydraulic pressure control unit 601 receives the required hydraulic pressure P2 of the hydraulic actuator, and sets the maximum hydraulic pressure as the target hydraulic pressure from among the base hydraulic pressure P1 and the required hydraulic pressure P2. Depending on the operating state of the engine 100, there may be a plurality of required oil pressures P2. If there is no required oil pressure P2, the oil pressure control unit 601 sets the base oil pressure P1 as the target oil pressure.

  From another viewpoint, the base oil pressure P1 is a provisional target oil pressure. When the required hydraulic pressure P2 of the hydraulic actuator is present and the hydraulic pressure P2 is larger than the base hydraulic pressure P1, the hydraulic pressure P2 is set to the target hydraulic pressure.

  Next, the hydraulic control unit 601 calculates the corrected target hydraulic pressure by increasing the target hydraulic pressure based on the hydraulic pressure reduction allowance when the oil flows from the oil pump 81 to the position of the hydraulic pressure sensor 50a. The oil pressure reduction allowance is stored in advance in the memory. The oil pressure control unit 601 converts the corrected target oil pressure into a flow rate (discharge amount and therefore discharge pressure) of the oil pump 81 to obtain a target flow rate (target discharge amount and thus target discharge pressure).

  Subsequently, the hydraulic control unit 601 corrects the target flow rate. Specifically, the hydraulic control unit 601 converts the predicted operation amount of the exhaust side VVT 18 when operating the exhaust side VVT 18 to obtain a consumed flow rate when the exhaust side VVT 18 is operated. The predicted operation amount of the exhaust side VVT 18 can be obtained from the difference between the current operation angle and the target operation angle and the engine speed. Further, the hydraulic pressure control unit 601 converts the predicted operation amount of the valve stop mechanisms 45d and 46d when the valve stop mechanisms 45d and 46d are operated to obtain a flow rate consumed when the valve stop mechanisms 45d and 46d are operated. Further, the hydraulic control unit 601 obtains a consumption flow rate when the oil jet 71 is operated. The hydraulic control unit 601 obtains a consumed flow rate corresponding to the hydraulic actuator to be operated, and corrects the target flow rate using the consumed flow rate.

  During the steady operation of the engine 100, the predicted operation amount of each hydraulic actuator is zero (0), so that the target hydraulic pressure is not corrected according to the operation of the hydraulic actuator. On the other hand, during the transient operation of engine 100, the target hydraulic pressure is corrected according to the hydraulic actuator that operates. That is, the discharge amount (discharge pressure) of the oil pump 81 is corrected and controlled.

  Further, the hydraulic control unit 601 corrects the target flow rate with the hydraulic feedback amount. This hydraulic pressure feedback amount is the predicted hydraulic pressure that predicts how the hydraulic pressure (actual hydraulic pressure) detected by the hydraulic pressure sensor 50a changes with respect to the change in the target hydraulic pressure during the transient operation of the engine 100, and the detected actual pressure. It is a value according to the deviation from the hydraulic pressure. When the actual hydraulic pressure is higher than the predicted hydraulic pressure, the hydraulic feedback amount becomes a negative value and the target flow rate is reduced. On the other hand, when the actual hydraulic pressure is lower than the predicted hydraulic pressure, the hydraulic feedback amount becomes a positive value and the target flow rate is increased. . If the actual oil pressure is the same as the predicted oil pressure, the oil pressure feedback amount is 0, that is, no correction based on the oil pressure feedback amount is performed.

  During the transient operation of the engine 100, when the target oil pressure changes, for example, in a step shape, the oil pressure includes a response delay of the oil pump 81, a response delay until the oil pressure reaches the position of the oil pressure sensor 50a from the oil pump 81, and the like. Due to the response delay, the actual hydraulic pressure follows the change in the target hydraulic pressure with a delay. Such a change in the actual oil pressure due to a delay in the response of the oil pressure can be predicted based on a dead time or a time constant determined in advance by experiments or the like, and the predicted oil pressure thus predicted is set. However, during the steady operation of the oil pump 81, the predicted hydraulic pressure is the same as the target hydraulic pressure, and is substantially the same as the hydraulic feedback control that feeds back the deviation between the target hydraulic pressure and the actual hydraulic pressure.

  When the deviation between the target hydraulic pressure and the actual hydraulic pressure is fed back, due to the delay in response of the hydraulic pressure, the deviation between the target hydraulic pressure and the actual hydraulic pressure immediately after the target hydraulic pressure changes becomes too large, and the actual hydraulic pressure overshoots the target hydraulic pressure. And undershoot easily occur. In particular, when the oil pump 81 deteriorates, the deviation becomes larger. On the other hand, since the deviation between the predicted hydraulic pressure and the actual hydraulic pressure is usually small, the actual hydraulic pressure changes approximately along the predicted hydraulic pressure by feeding back the deviation between the predicted hydraulic pressure and the actual hydraulic pressure. Overshoot and undershoot against hydraulic pressure are less likely to occur. As a result, the actual hydraulic pressure can be smoothly matched with the target hydraulic pressure. Further, even if the deviation between the target hydraulic pressure and the actual hydraulic pressure immediately after the target hydraulic pressure has changed due to the deterioration of the oil pump 81, the actual hydraulic pressure will change substantially along the predicted hydraulic pressure. Overshoot and undershoot of the actual hydraulic pressure with respect to the target hydraulic pressure are less likely to occur.

  The hydraulic control unit 601 sets the target duty ratio by comparing the corrected target flow rate and the engine rotation speed with the duty ratio map, and transmits a control signal having the target duty ratio to the oil control valve 84. . Next, the discharge amount control of the oil pump 81 by the hydraulic control unit 601 and the operation control of the engine 100 by the operation control unit 602 will be described with reference to the flowcharts of FIGS.

  In step S1, the hydraulic control unit 601 reads the engine load, the engine rotation speed, the oil temperature, and the water temperature. In step S2, the hydraulic control unit 601 determines whether or not the operating condition of the hydraulic operating device is satisfied based on the engine load, the engine speed, and the like.

  If the operating condition of the hydraulic operating device is not satisfied, the hydraulic control unit 601 obtains a base hydraulic pressure P1 corresponding to the engine rotational speed and the oil temperature from the base hydraulic pressure map in step S4.

  On the other hand, when the operating condition of the hydraulic actuator is satisfied, the hydraulic control unit 601 reads the required hydraulic pressure P2 corresponding to the hydraulic actuator that satisfies the condition from the map (step S3). Thereafter, the hydraulic control unit 601 proceeds to step S4, and obtains the base hydraulic pressure P1 as described above.

  Then, the hydraulic control unit 601 compares the base hydraulic pressure P1 and the required hydraulic pressure P2, and sets the highest hydraulic pressure as the target hydraulic pressure (step S5). If the required oil pressure P2 does not exist, the oil pressure control unit 601 sets the base oil pressure P1 to the target oil pressure.

  Subsequently, the hydraulic pressure control unit 601 calculates a corrected target hydraulic pressure by adding a hydraulic pressure reduction margin to the target hydraulic pressure (step S6), and converts the corrected target hydraulic pressure into a flow rate to obtain a target flow rate (target discharge amount) ( Step S7). Furthermore, the hydraulic control unit 601 corrects the target flow rate according to the hydraulic actuator that operates (step S8). For example, the hydraulic control unit 601 adds the consumption flow rate when the VVT is activated, the consumption flow rate when the valve stop mechanism is activated, and / or the consumption flow rate when the oil jet is activated to the target flow rate.

  In step S9, the hydraulic control unit 601 sets the target duty ratio by comparing the target flow rate with the duty ratio map. The hydraulic control unit 601 reads the duty ratio of the current control signal (hereinafter referred to as “current duty ratio”) and determines whether the current duty ratio matches the target duty ratio (step S10). If the current duty ratio does not match the target duty ratio, the hydraulic control unit 601 changes the duty ratio of the control signal to the target duty ratio, and outputs the control signal to the oil control valve 84 (step S11). Thereafter, the hydraulic control unit 601 proceeds to step S12. On the other hand, if the current duty ratio matches the target duty ratio, the hydraulic control unit 601 proceeds to step S12 without passing through step S11.

  In step S12, the hydraulic control unit 601 reads the hydraulic pressure of the hydraulic sensor 50a (hereinafter referred to as “actual hydraulic pressure”). Then, the hydraulic control unit 601 determines whether or not the actual hydraulic pressure matches the target hydraulic pressure in step S5 (step S13).

  If the actual hydraulic pressure and the target hydraulic pressure match, the hydraulic pressure control unit 601 proceeds to step S14. In step S14, the hydraulic control unit 601 reads the engine load, the engine rotation speed, and the oil temperature. Then, the hydraulic control unit 601 determines whether the engine load, the engine speed, or the oil temperature has changed from the value read in Step S1 (Step S15). If the engine load, the engine rotation speed, and the oil temperature have not changed, the hydraulic control unit 601 returns to step S12 and repeats the process from reading the actual hydraulic pressure. That is, when the engine load, the engine rotation speed, and the oil temperature do not change, the target hydraulic pressure is also constant, so the hydraulic pressure control unit 601 continues to monitor whether the actual hydraulic pressure matches the target hydraulic pressure. On the other hand, if any of the engine load, the engine rotation speed, and the oil temperature has changed, the hydraulic control unit 601 returns to step S2 and repeats the processes after step S2. That is, the hydraulic control unit 601 starts over from setting the target hydraulic pressure.

  If the actual oil pressure and the target oil pressure do not match in step S13, the oil pressure control unit 601 adjusts the duty ratio of the control signal based on the deviation between the actual oil pressure and the target oil pressure, and the control signal is sent to the oil control valve 84. (Step S16). Then, the oil pressure control unit 601 reads the actual oil pressure of the oil pressure sensor 50a (step S17), and determines whether or not the actual oil pressure matches the target oil pressure of step S5 (step S18).

  That is, in steps S16 to S18, the hydraulic pressure control unit 601 adjusts the duty ratio of the control signal to check whether the actual hydraulic pressure matches the target hydraulic pressure. When the actual hydraulic pressure becomes equal to the target hydraulic pressure by this adjustment, the hydraulic pressure control unit 601 proceeds to step S14 described above. On the other hand, if the actual hydraulic pressure and the target hydraulic pressure do not match even after this adjustment, the hydraulic pressure control unit 601 proceeds to step S19 and performs further adjustment of the duty ratio.

  In step S19, the hydraulic control unit 601 determines whether or not the actual hydraulic pressure is greater than the target hydraulic pressure. When the actual oil pressure is larger than the target oil pressure, the oil pressure control unit 601 increases the duty ratio of the control signal by a predetermined amount in order to reduce the discharge amount of the oil pump 81 (step S20). Then, the hydraulic control unit 601 reads the actual hydraulic pressure and determines whether or not the state where the actual hydraulic pressure is larger than the target hydraulic pressure continues (step S21). If the actual oil pressure is not greater than the target oil pressure, the oil pressure control unit 601 returns to step S18 and determines whether or not the actual oil pressure matches the target oil pressure. On the other hand, when the actual oil pressure is still larger than the target oil pressure, the oil pressure control unit 601 determines whether the duty ratio is the upper limit value (step S22). The duty ratio includes an upper limit value and a lower limit value corresponding to an adjustable range of the flow rate of oil supplied from the oil control valve 84 to the oil pump 81. If the duty ratio is not the upper limit value, the hydraulic pressure control unit 601 returns to step S20, and again increases the duty ratio of the control signal by a predetermined amount.

  As described above, when the actual hydraulic pressure is larger than the target hydraulic pressure, the duty ratio of the control signal is increased by a predetermined amount until the actual hydraulic pressure becomes lower than the target hydraulic pressure or the duty ratio reaches the upper limit value. Move closer to the target hydraulic pressure. When the actual oil pressure matches the target oil pressure, the adjustment of the duty ratio is once ended, and the processing of the oil pressure control unit 601 proceeds to step S14 via step S18.

  On the other hand, when the actual hydraulic pressure is smaller than the target hydraulic pressure, the hydraulic pressure control unit 601 decreases the duty ratio of the control signal by a predetermined amount (step S23). Then, the oil pressure control unit 601 reads the actual oil pressure and determines whether or not the state where the actual oil pressure is smaller than the target oil pressure continues (step S24). If the actual oil pressure is not smaller than the target oil pressure, the oil pressure control unit 601 returns to step S18 and determines whether or not the actual oil pressure matches the target oil pressure. On the other hand, when the actual oil pressure is still smaller than the target oil pressure, the oil pressure control unit 601 determines whether or not the duty ratio is the lower limit value (step S25). If the duty ratio is not the lower limit value, the hydraulic pressure control unit 601 returns to step S23 and again decreases the duty ratio of the control signal by a predetermined amount.

  As described above, when the actual hydraulic pressure is smaller than the target hydraulic pressure, the duty ratio of the control signal is decreased by a predetermined amount until the actual hydraulic pressure becomes equal to or higher than the target hydraulic pressure or the duty ratio reaches the lower limit value. Move closer to the target hydraulic pressure. When the actual oil pressure matches the target oil pressure, the adjustment of the duty ratio is once ended, and the processing of the oil pressure control unit 601 proceeds to step S14 via step S18.

  In this way, when the actual hydraulic pressure does not match the target hydraulic pressure in step S13, the hydraulic pressure control unit 601 adjusts the duty ratio of the control signal by executing steps S16 to S25 so that the actual hydraulic pressure becomes the target hydraulic pressure. To match.

  By the way, due to the malfunction of the oil supply device 200, even if the duty ratio of the control signal is adjusted to the limit, the actual oil pressure may not match the target oil pressure. For example, when the oil control valve 84 is not operating normally, the flow rate of oil supplied to the oil pump 81 via the oil control valve 84 is equal to the duty ratio even if the duty ratio of the control signal is adjusted. May not change (in some cases it does not change at all). In such a state, when the duty ratio is increased or decreased, the actual oil pressure does not match the target oil pressure, and the duty ratio reaches the upper limit value or the lower limit value. Alternatively, when a large oil leak occurs in the oil supply passage 5, the actual oil pressure does not increase even if the discharge amount of the oil pump 81 is increased. To reach. In addition to oil leakage in the oil control valve 84 and the oil supply passage 5, the actual hydraulic pressure is the target as described above even when the oil pump 81, the hydraulic sensor 50a, the hydraulic operation parts, and the lubrication part are defective. The duty ratio can reach the upper limit value or the lower limit value without matching the hydraulic pressure.

  Therefore, when the actual oil pressure does not match the target oil pressure and the duty ratio reaches the upper limit value or the lower limit value (hereinafter, this state is referred to as “hydraulic pressure abnormality”), the controller 60 changes the operating state of the engine 100. Some restrictions. As the oil pressure abnormality, there are a high oil pressure abnormality, which is a case where the actual oil pressure is higher than the target oil pressure, and a low oil pressure abnormality where the actual oil pressure is lower than the target oil pressure. The contents of the limited operation of the engine 100 are changed depending on the situation.

  Specifically, when the duty ratio reaches the upper limit value (YES in step S22), the actual hydraulic pressure is abnormally high when it is too high. As the duty ratio increases, the flow rate of the oil supplied to the oil pump 81 via the oil control valve 84 increases, so the capacity of the oil pump 81 decreases. That is, when the duty ratio reaches the upper limit value, it is when the actual oil pressure is being reduced, that is, when the actual oil pressure is too high. In this case, the operation control unit 602 determines that there is a failure (step S26), and shifts to the first failsafe mode (step S27).

  In the first failsafe mode, the operation control unit 602 prohibits an operation with a high engine rotation speed or a large engine load. Specifically, as shown in FIG. 12, the operation control unit 602 sets the engine rotation speed within a range in which the engine load does not exceed the predetermined first upper limit rotation speed Vh and the engine load does not exceed the predetermined first upper limit load Ph. The operating state of engine 100 is limited.

  Since the oil pump 81 is driven by the engine 100, if the capacity is constant, the discharge amount of the oil pump 81 increases as the engine speed increases. Therefore, when the actual oil pressure is higher than the target oil pressure and the actual oil pressure cannot be controlled, the operation control unit 602 restricts the operation on the high rotation side of the engine, so that the discharge amount of the oil pump 81 becomes too high. To suppress that. In this way, an excessive discharge amount of the oil pump 81 is suppressed by restricting the operation of the engine 100, so that an oil leak in the oil supply device 200 (for example, an oil leak from the oil filter 82 or the like) or an error in the hydraulic operation device. The operation can be suppressed. The first upper limit rotational speed Vh is an upper limit engine speed that is allowed when the actual hydraulic pressure is too high, and the first upper limit load Ph is an upper limit engine load that is allowed when the actual hydraulic pressure is too high.

  On the other hand, when the duty ratio reaches the lower limit value (YES in step S25), the actual oil pressure is too low than the target oil pressure when the oil pressure is abnormal. As the duty ratio decreases, the flow rate of the oil supplied to the oil pump 81 via the oil control valve 84 decreases, so the capacity of the oil pump 81 increases. That is, when the duty ratio reaches the upper limit value, it is when the actual hydraulic pressure is being increased, that is, when the actual hydraulic pressure is too low. In this case, the operation control unit 602 determines whether the actual oil pressure is less than a predetermined lower limit oil pressure (step S28). The lower limit hydraulic pressure is a minimum hydraulic pressure necessary for operating the engine 100, which is determined in consideration of seizure in the lubrication portion. That is, when the actual hydraulic pressure is too low, the operation control unit 602 determines whether or not the necessary minimum hydraulic pressure is secured.

  If the actual hydraulic pressure is equal to or higher than the lower limit hydraulic pressure, the operation control unit 602 determines that there is a failure (step S29) and shifts to the second failsafe mode (step S30). As shown in FIG. 13, the second fail-safe mode is an operation mode that restricts the operation on the high rotation side and the high load side of the engine, similarly to the first fail sail mode. However, the upper limit rotational speed and upper limit load of the operable range of engine 100 are set to values corresponding to the case where the actual hydraulic pressure is too low. Specifically, the operation control unit 602 limits the operation state of the engine 100 to a range in which the engine rotation speed does not exceed the predetermined second upper limit rotation speed Vl and the engine load does not exceed the predetermined second upper limit load Pl. To do. The second upper limit rotational speed Vl is an upper limit engine speed that is allowed when the actual hydraulic pressure is too low, and the second upper limit load Pl is an upper limit engine load that is allowed when the actual hydraulic pressure is too low. The second upper limit rotation speed Vl may be a value different from the first upper limit rotation speed Vh or the same value. The second upper limit load Pl may be a different value or the same value as the first upper limit load Ph.

  In this way, by restricting the operation on the high rotation side and the high load side of the engine, the required hydraulic pressure in the lubrication part can be reduced. That is, the higher the engine speed and the higher the engine load, the higher the required oil pressure in the lubrication part. By restricting the operation on the high rotation side and high load side of the engine, the required oil pressure in the lubrication part can be reduced, so even if the actual oil pressure is too low, the occurrence of poor lubrication in the lubrication part is suppressed. can do.

  On the other hand, when the actual hydraulic pressure is less than the lower limit hydraulic pressure, the operation control unit 602 determines that there is a failure (step S31) and shifts to the retreat mode (step S32). The evacuation mode is an operation mode that secures the minimum travelability that allows the vehicle to be driven to a safe place such as a road shoulder on the premise that the operation of the engine 100 is immediately stopped. Specifically, in the retreat mode, the operation control unit 602 causes the engine 100 to fall within a range where the engine speed does not exceed the predetermined third upper limit speed Vx and the engine load does not exceed the predetermined third upper limit load Px. Limit the operating state of The third upper limit rotation speed Vx is a value smaller than the second upper limit rotation speed Vl. The third upper limit load Px is a value smaller than the second upper limit load Pl.

  In addition, the operation control unit 602 corrects the first upper limit rotation speed Vh in the first fail safe mode and the second upper limit rotation speed Vl in the second fail safe mode according to the oil temperature.

  Specifically, when the oil pump 81 has a maximum capacity and cannot be controlled, the maximum hydraulic pressure Pmax of the oil pump 81 increases as the engine speed increases, as shown in FIG. When the engine rotation speed becomes Vh1, the maximum hydraulic pressure Pmax reaches the upper limit hydraulic pressure Plmt1. The upper limit oil pressure Plmt1 is an upper limit value of the allowable oil pressure as the oil supply apparatus 200, and is an oil pressure that causes oil leakage or malfunction of the hydraulic operation device when exceeding this. The engine rotational speed at which the maximum hydraulic pressure Pmax reaches the upper limit hydraulic pressure Plmt1 is the first upper limit rotational speed Vh in the first failsafe mode. That is, in the first failsafe mode, engine 100 is operated at an engine speed equal to or lower than the maximum hydraulic pressure Pmax reaching upper limit hydraulic pressure Plmt1.

  The maximum oil pressure Pmax of the oil pump 81 varies not only with the engine speed but also with the oil temperature. Since the oil viscosity decreases as the oil temperature increases, the discharge efficiency of the oil pump 81 decreases. That is, even if the engine speed is the same, the maximum oil pressure Pmax decreases as the oil temperature increases. Further, the rate of change (inclination) of the maximum hydraulic pressure Pmax with respect to the engine rotation speed decreases as the oil temperature increases. As a result, the first upper limit rotation speed Vh increases as the oil temperature increases. In the example of FIG. 14, when the oil temperature rises from T1 to T2, the rate of change of the maximum hydraulic pressure Pmax with respect to the engine rotation speed decreases, and the first upper limit rotation speed increases from Vh1 to Vh2.

  Correspondingly, as shown in FIG. 12, the operation control unit 602 increases the first upper limit rotation speed Vh in the first fail-safe mode as the oil temperature increases. Thereby, the operable range of engine 100 in the first fail-safe mode is expanded to the higher rotation side as the oil temperature becomes higher.

  On the other hand, when control is impossible when the capacity of the oil pump 81 is at a minimum, the minimum oil pressure Pmin of the oil pump 81 is the engine speed except when the engine speed is very small as shown in FIG. It is almost constant regardless of the speed. If the minimum oil pressure Pmin is larger than the lower limit oil pressure Plmt2 that is the lower limit value of the allowable oil pressure as the oil supply device 200, the engine 100 can be operated without any problem. However, as shown in FIG. 14, the lower limit hydraulic pressure Plmt2 changes according to the engine speed. Specifically, the lower limit hydraulic pressure Plmt2 increases as the engine speed increases. That is, as the engine rotation speed increases, the required hydraulic pressure in the lubrication unit increases, and accordingly, the lower limit hydraulic pressure Plmt2 also increases. Therefore, when the engine rotation speed is low, the minimum oil pressure Pmin is greater than the lower limit oil pressure Plmt2, but when the engine rotation speed increases, the minimum oil pressure Pmin becomes lower than the lower limit oil pressure Plmt2. The engine rotation speed when the minimum hydraulic pressure Pmin reaches the lower limit hydraulic pressure Plmt2 is the second upper limit rotation speed Vl in the second failsafe mode. That is, in the second fail-safe mode, the engine 100 is operated at an engine speed equal to or lower than the engine speed at which the minimum oil pressure Pmin reaches the lower limit oil pressure Plmt2.

  This lower limit oil pressure Plmt2 changes not only with the engine speed but also with the oil temperature. Since the viscosity of the oil increases as the oil temperature decreases, an oil film in the lubrication part is easily secured. That is, as the oil temperature decreases, the required oil pressure in the lubrication portion decreases, so even if the engine speed is the same, the lower limit oil pressure Plmt2 decreases as the oil temperature decreases. As a result, the second upper limit rotation speed Vl increases as the oil temperature decreases. In the example of FIG. 14, when the oil temperature decreases from T3 to T4, the second upper limit rotation speed increases from V13 to V14.

  Correspondingly, as shown in FIG. 13, the operation control unit 602 increases the second upper limit rotation speed Vl in the second fail-safe mode as the oil temperature decreases. Thereby, the operable range of engine 100 in the second fail-safe mode is expanded to the higher rotation side as the oil temperature becomes lower.

  As described above, when the hydraulic pressure is abnormal, the operation control unit 602 limits the operation state of the engine 100 to a range in which the engine rotation speed does not exceed the first upper limit rotation speed Vh or the second upper limit rotation speed Vl. Thereby, the malfunction resulting from oil pressure control failure, such as oil leakage, malfunction of a hydraulic actuator, or lubrication failure of a lubrication part, is controlled. Further, at this time, the operation control unit 602 corrects the first upper limit rotation speed Vh or the second upper limit rotation speed Vl according to the oil temperature. That is, even when the oil temperature is abnormal, the operable range of engine 100 changes according to the oil temperature. Therefore, the operation control unit 602 does not limit the operation state of the engine 100 uniformly when the hydraulic pressure is abnormal, but appropriately adjusts the operation range of the engine 100 to be limited according to the oil temperature. Thus, when the oil temperature is abnormal, the operating state of engine 100 is appropriately limited according to the oil temperature, and the operating state of the engine is prevented from being unnecessarily limited. As a result, the traveling performance of the vehicle can be ensured.

<< Other Embodiments >>
As described above, the embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated by the said embodiment and it can also be set as new embodiment. In addition, among the components described in the accompanying drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to exemplify the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  About the said embodiment, it is good also as following structures.

  For example, in the above embodiment, the oil pump 81 is not limited to a variable displacement oil pump. The oil pump 81 may be an oil pump having a fixed capacity. In this case, the oil supply passage 5 is provided with a relief valve. The oil supply device 200 is controlled by the relief valve so that the actual oil pressure in the oil supply passage 5 is equal to or lower than a predetermined upper limit oil pressure. That is, the relief valve functions as a hydraulic control device.

  The oil pump 81 may be an electric oil pump instead of being driven by the crankshaft 26.

  Further, when the duty ratio reaches the upper limit value or the lower limit value, the operation control unit 602 determines that there is a high hydraulic pressure abnormality or a low hydraulic pressure abnormality, and any one of the first fail-safe mode, the second fail-safe mode, and the evacuation mode. Is configured to migrate to. However, the operation control unit 602 may determine that there is a high hydraulic pressure abnormality or a low hydraulic pressure abnormality when the state where the duty ratio has reached the upper limit value or the lower limit value has continued for a predetermined period.

  Further, the operation control unit 602 corrects the upper limit rotation speed of the operation region of the engine 100 according to the oil temperature in the first fail safe mode and the second fail safe mode, but the upper limit load of the operation region of the engine 100 is also oil. You may correct | amend according to temperature. For example, in the first failsafe mode, the operation control unit 602 may increase the first upper limit load Ph in the operation region of the engine 100 as the oil temperature increases. In the second fail-safe mode, the operation control unit 602 may increase the second upper limit load Pl in the operation region of the engine 100 as the oil temperature decreases.

  As described above, the technique disclosed herein is useful for an engine oil supply apparatus.

100 Engine 5 Oil supply passage 50a Hydraulic sensor 60 Controller (control device)
601 Hydraulic control unit 602 Operation control unit 63 Oil temperature sensor 81 Oil pump (hydraulic control device)
84 Oil control valve (hydraulic control device, control valve)
200 Oil supply device

Claims (4)

A hydraulic sensor for detecting the hydraulic pressure of an oil supply path to which oil is supplied from a variable capacity oil pump driven by an engine;
A control valve for adjusting the flow rate of oil supplied to the variable capacity oil pump in order to adjust the capacity of the variable capacity oil pump;
An oil temperature sensor for detecting the oil temperature of the oil supply passage;
An operation control unit for controlling the operation of the engine,
The operation controller is
When the oil pressure of the oil supply path detected by the oil pressure sensor is out of the controllable range via the control valve, the engine operating state is within a range where the engine speed does not exceed a predetermined upper limit speed. Limit
An engine control device that corrects the upper limit rotational speed in accordance with an oil temperature detected by the oil temperature sensor. The engine control device according to claim 1 ,
The operation controller is
When the oil pressure in the oil supply passage is high and exceeds the controllable range, the engine operating state is limited to a range in which the engine rotational speed does not exceed the predetermined first upper limit rotational speed.
Controller features and to Rue engine to be corrected in accordance with the first upper limit rotation speed to the oil temperature detected by the oil temperature sensor. The engine control device according to claim 1 or 2 ,
The operation controller is
When the oil pressure in the oil supply passage is lower than the controllable range and is in a low oil pressure abnormality, the engine operating state is limited to a range in which the engine rotation speed does not exceed a predetermined second upper limit rotation speed,
Controller features and to Rue engine to be corrected in accordance with the second upper limit rotation speed to the oil temperature detected by the oil temperature sensor. The engine control device according to claim 3 ,
When the oil pressure in the oil supply passage is below the controllable range and less than a predetermined lower limit oil pressure, the operation control unit has a third upper limit rotation speed that is smaller than the second upper limit rotation speed. The engine control device limits the engine operating state to a range in which the engine load does not exceed a predetermined upper limit load.

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