JP2017044097A - Hydraulic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic control device which can determine a failure of a selector valve (OSV5) to select the supply/cut-off of oil to/from a piston jet nozzle 15 when using hydraulic variable means (for example, a capacity variable mechanism for an oil pump 3) for performing feedback control of hydraulic pressure according to a detected value for the hydraulic pressure in an oil supply system 2 for an engine 1.SOLUTION: The hydraulic control device includes an oil level sensor 106 which can measure the oil level of oil stored in an oil pan 11. When an oil level thus measured is higher than a reference oil level at least by a first threshold value (Step ST206: YES), if an ECU 100 controls the OSV5 to be at a supply position (Step ST207: YES), the hydraulic control device determines a closing failure (Step ST208: failure determining means).SELECTED DRAWING: Figure 6

Description

  The present invention relates to a hydraulic control device for an engine, and particularly relates to determination of a failure suitable for an oil pressure that can be changed by a variable displacement oil pump or the like.

  Conventionally, in an oil supply system of an engine, oil stored in an oil pan is generally pumped up by an oil pump and supplied to various lubricating parts such as a cylinder, a crank journal, and a valve train. Some have a piston jet nozzle for injecting oil from below to cool the piston. As an example, the engine described in Patent Document 1 includes a switching valve that is switched to supply or shut off oil to the nozzle (referred to as a nozzle of an oil jet device in the same document).

  In the conventional engine, for example, for a while after the cold start, the oil flow is blocked by the switching valve so that the oil is not injected from the nozzle toward the piston. Thereby, engine warm-up can be promoted. On the other hand, after the warm-up is completed, oil is supplied by the switching valve and is injected from the nozzle toward the piston. Further, in the above-mentioned conventional example, assuming that the switching valve is stuck due to, for example, a failure of an electromagnetic solenoid or a foreign object being caught, the switching valve is switched to either the supply or shut-off state, and the hydraulic pressure detection value is thereby determined. When the change in is less than or equal to a predetermined value, it is determined that the switching valve has failed.

JP 2014-098344 A

  By the way, an engine oil pump is usually driven by a crankshaft via a chain, a gear, or the like. Therefore, in order to reduce the power loss (pump drive loss) of the engine, the hydraulic pressure is reduced in a light load operation state. It has been proposed to reduce For this purpose, it is conceivable to employ a variable displacement oil pump, change the pump displacement based on a signal from a hydraulic sensor disposed in the main gallery, and perform feedback control of the hydraulic pressure.

  However, when the feedback control of the hydraulic pressure is performed in this way, the switching valve is operated as in the conventional example, and the failure of the switching valve is determined based on the change in the hydraulic pressure detected at that time. It becomes difficult. This is because the hydraulic pressure such as the main gallery of the engine is immediately restored by the hydraulic feedback control even if it temporarily changes with the operation of the switching valve.

  In view of such problems, the object of the present invention is to determine whether a switching valve that switches between supplying and shutting off oil to the piston jet nozzle is defective even when the oil pressure of the engine oil supply system is feedback controlled. Is to be able to do it.

  The present invention provides a hydraulic pressure variable means capable of changing the hydraulic pressure of an oil supply system, a switching valve that is switched to supply or shut off oil to a piston jet nozzle that injects oil toward the piston, and an oil pan. And an oil level sensor capable of measuring the oil level height of the stored oil. The oil pressure is changed by the oil pressure variable means according to the detected value of the oil pressure by the oil pressure sensor provided in the oil supply system. It is intended for a hydraulic control device that performs feedback control of the motor.

  The switching valve control means for switching the switching valve to either the supply or shut-off state is provided, and is set according to the oil level height measured by the oil level sensor and the state of the switching valve. Failure determination means for determining failure of the switching valve based on a difference from the reference oil level height is provided.

  Note that the oil level of the oil stored in the oil pan varies depending on the amount of oil discharged by the oil pump (that is, the amount of suction from the oil pan). Therefore, when the switching valve is in the supply state and oil is being injected from the piston jet nozzle, the oil level is lower than when the switching valve is in the shut-off state. In general, the discharge amount of the oil pump changes according to the engine speed and the like, and the oil level also changes accordingly.

  Furthermore, in the case of a variable displacement oil pump, the discharge amount of the oil pump may be changed according to the engine load, and the oil temperature is low and the oil viscosity is high after the engine is started. In this case as well, since the discharge amount of the oil pump changes, the oil level in the oil pan also changes depending on the oil temperature and the engine load. Therefore, it is preferable that the reference oil level height is set so as to change according to the engine load, the rotational speed, and the oil temperature as well as the state of the switching valve.

  With the above configuration, when the switching valve is controlled by the switching valve control means while the engine is running, for example, when oil is supplied to the piston jet nozzle, the oil pump discharge amount increases accordingly. Therefore, the oil level in the oil pan should be low, and the reference oil level is set to correspond to this. On the contrary, when the switching valve is controlled to be in the shut-off state, the oil pump discharge amount is relatively small, so the oil level in the oil pan should be high. Surface height is set. Then, based on the difference between the reference oil level height and the oil level height measured by the oil level sensor, a failure of the switching valve is determined by the failure determination means.

  That is, for example, the failure determination means is configured such that when the switching valve control means controls the switching valve to be in a supply state, the oil level height measured by the oil level sensor is higher than the reference oil level height, and If the difference between the two is equal to or greater than the first threshold, it is determined that the switching valve is closed. The oil level of the oil stored in the oil pan is higher than the reference oil level by more than a predetermined level, which means that the piston jet nozzle is On the other hand, no oil is supplied, and from this, it can be determined that the switching valve is in a closed failure with the shut-off state being maintained. The first threshold value of the oil level is determined in advance by an experiment or the like so that a change in the oil level due to such a closing failure of the switching valve can be determined separately from a variation in the normal oil level. You only have to set it.

  Preferably, the failure determination means has an oil level height measured by the oil level sensor lower than a reference oil level height when the switching valve control means controls the switching valve to be in a shut-off state, and both If the difference is equal to or greater than the second threshold value, it is determined that the switching valve is in an open failure while remaining in the supply state. In this way, it is possible to determine the open failure as well as the close failure of the switching valve.

  In addition, preferably, when the failure determining means determines that the switching valve is closed, a warning is issued and a fail-safe means for limiting the engine output is provided. In this way, it is possible to prevent the piston from being overheated due to the failure of the switching valve being closed and the piston jet nozzle being not supplied with oil regardless of the situation in which the oil should be injected and cooled.

  On the other hand, when it is determined by the failure determination means that the switching valve is open, it is preferable that an alarm is issued by the fail-safe means while the engine output is not limited. If the switching valve is open and remains in the supply state, the engine warm-up is delayed or heat loss increases, resulting in fuel consumption deterioration, but there is no problem of piston overheating. Therefore, the engine output is not limited and drivability is ensured.

  Further, the switching valve control means may control the switching valve to be in a supply state or a cutoff state in accordance with the temperature state and the operating state of the engine. By doing this, it is possible to determine the failure of the switching valve while controlling the switching valve in accordance with the state of the engine and performing normal control for switching between supply and cutoff of oil to the piston jet nozzle.

  In other words, if the operation is to inject oil into the piston and if it is forced to shut off in order to determine the failure of the switching valve, oil injection from the piston jet nozzle will not be performed and the piston may overheat. There is. On the other hand, in the operation state where the injection of oil should be stopped, there is a situation that even if the switching valve is forcibly supplied, the oil level is hardly lowered and it is difficult to make a determination. Therefore, it is preferable to determine the failure while controlling the normal switching valve as described above.

  Furthermore, as described above, it is preferable to set the reference oil level height so as to change not only according to the state of the switching valve but also according to the engine load and rotation speed, and also the oil temperature. Instead, the height of the oil level of the oil stored in the oil pan also changes due to variations in the amount of oil that the user is injecting into the oil pan. For this reason, it is preferable to provide oil level height calibration means for calibrating the reference oil level height in a predetermined operating state of the engine.

  According to the hydraulic control device of the present invention, the oil level in the oil pan is largely deviated from the reference oil level by a predetermined amount or more during the operation of the engine. It is possible to determine the failure of the switching valve that switches between supply and shut-off. Thus, based on the height of the oil level, the failure of the switching valve can be determined even if the feedback control of the hydraulic pressure is performed.

It is a schematic structure figure showing the oil pressure control device of the engine concerning the embodiment of the present invention, and shows the state where the capacity of an oil pump is the maximum. FIG. 2 is a view corresponding to FIG. 1 showing a state where the pump capacity is minimum. It is a graph which shows an example of the correlation with an OCV electric current value, an engine speed, and a pump discharge pressure. It is a flowchart which shows the main routine of the hydraulic control of an engine. It is an image figure of the oil level height map which set the reference oil level height which changes according to a load factor and rotation speed of an engine in a jet injection field and a jet stop field, respectively. 5 is a flowchart of an OSV failure diagnosis routine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a case where the present invention is applied to an oil pump of an engine mounted on an automobile will be described, but the present invention is not limited to this.

-Schematic configuration of oil supply system-
As schematically shown in FIG. 1, an oil pan 11 is disposed at the lower part of the engine 1 and stores engine oil (hereinafter simply referred to as oil) for lubricating pistons, crank journals and the like (not shown). Has been. The engine 1 is also provided with an oil supply system 2 that draws oil from an oil pan 11 and supplies it to the piston, crank journal, and the like. That is, the oil pump 3 driven by the crankshaft 12 pumps up the oil in the oil pan 11 through the strainer 13, passes through an oil filter (not shown), and feeds it to the main gallery 20.

  Although not shown, oil is supplied from the main gallery 20 to the valve train of the engine 1, its variable mechanism, the crank journal, the chain tensioner, and the like through a plurality of oil passages. Thus, the oil supplied to each lubricating part of the engine 1 flows down the oil dropping passage and is stored in the oil pan 11 again. In the present embodiment, a branch passage 14a that branches from the high-pressure oil passage 14 from the oil pump 3 to the main gallery 20 is provided, and oil is also supplied to the piston jet nozzle 15 through the branch passage 14a.

  The piston jet nozzle 15 injects oil from below toward the piston, and a check ball 15a is disposed at a portion communicating with the branch passage 14a. That is, if the hydraulic pressure of the branch passage 14a is less than a predetermined value, the check ball 15a closes the communication portion with the branch passage 14a by the urging force of the spring 15b. On the other hand, when the hydraulic pressure in the branch passage 14a becomes equal to or higher than a predetermined value, the communicating portion with the branch passage 14a is opened, and oil flows into the piston jet nozzle 15 and is injected toward the upper piston.

  The branch passage 14a is provided with an oil switching valve (OSV) 5. The supply port 5a communicates with the upstream side of the branch passage 14a, and the discharge port 5b is downstream of the branch passage 14a. It communicates with the side. As an example, the OSV 5 is a switching valve that operates the spool 52 by an electromagnetic solenoid 51. The supply valve 5a and the discharge port 5b communicate with each other, and the supply port 5a and the discharge port 5b are blocked. Can be switched.

  That is, the OSV 5 is a switching valve that is disposed in the branch passage 14 a and is switched to supply or shut off oil to the piston jet nozzle 15. If the OSV 5 is switched to the supply position and oil is supplied to the piston jet nozzle 15 through the branch passage 14a, the oil can be injected toward the piston as described above. On the other hand, if the OSV 5 is switched to the shut-off position, oil injection from the piston jet nozzle 15 toward the piston can be stopped.

-Oil pump-
As shown in FIG. 2 in addition to FIG. 1, the oil pump 3 is an internal gear pump. The housing 30 has a drive rotor 31 of an external gear and a driven rotor 32 of an internal gear that rotates in mesh with the drive rotor 31. And is housed. The outer periphery of the driven rotor 32 is held by an adjustment ring 33. As will be described later, when the drive rotor 31 and the driven rotor 32 are displaced by the operation of the adjustment ring 33, the pump displacement is changed. Yes.

  The drive rotor 31 is attached to the end of the crankshaft, and the center of the driven rotor 32 is eccentric by a predetermined amount with respect to the center of the drive rotor 31. The outer teeth 31a of the drive rotor 31 and the inner teeth 32a of the driven rotor 32 are meshed with each other on the eccentric side (the upper right side in FIG. 1), and the crescent-like shape between these two rotors 31 and 32 is engaged. A plurality of working chambers R are formed in the space along the circumferential direction.

  These working chambers R are designed to gradually increase or decrease in volume while moving in the circumferential direction as the two rotors 31 and 32 rotate, and the range in which the volume gradually increases. In the range (the discharge range shown on the left side of FIG. 1) in which oil is sucked from the suction port 30a formed in the housing 30 while the volume gradually decreases (the discharge range shown on the left side of FIG. 1). The oil is sent out to the discharge port 30b formed at 30 while being pressurized.

  The suction port 30a is connected to the strainer 13 via a suction pipe, while the discharge port 30b is connected to the high-pressure oil passage 14 via a discharge oil passage. Then, when the drive rotor 31 and the driven rotor 32 rotate while meshing with each other by the rotation of the crankshaft 12, the working chamber R that moves in the suction range as described above is sucked oil through the strainer 13 and the suction port 30a, From the working chamber R that moves in the discharge range, oil is discharged into the high-pressure oil passage 14 via the discharge port 30b.

-Capacity variable mechanism-
Further, the oil pump 3 is provided with a variable capacity mechanism capable of changing the amount of oil discharged every rotation of the crankshaft, that is, the pump capacity as described above. This capacity variable mechanism rotates (displaces) the adjustment ring 33 by the hydraulic pressure of the control space TC formed in the housing 30, and the relative positions of the drive rotor 31 and the driven rotor 32 with respect to the suction port 30 a and the discharge port 30 b. Is something that changes.

  That is, the adjustment ring 33 is formed with an arm portion 33a extending outward from the ring-shaped main body portion that holds the driven rotor 32, and the pressing force of the coil spring 34 acting on the arm portion 33a causes the adjustment portion 33 to It is biased to rotate clockwise. The direction in which the adjustment ring 33 rotates is regulated by guide pins 35 and 36 inserted into the elongated holes 33b and 33c.

  On the other hand, the hydraulic pressure of the control space TC formed in the housing 30 is applied to the arm portion 33a, and this hydraulic pressure (hereinafter referred to as control hydraulic pressure) causes the adjustment ring 33 to rotate counterclockwise in FIG. A pressing force that causes the to rotate is applied. The magnitude of the control oil pressure is controlled by an oil control valve (OCV) 4 through an oil passage 40 (hereinafter referred to as a control oil passage 40) that opens toward the control space TC.

  As an example, the OCV 4 is an electromagnetic proportional valve that operates the spool 42 by the linear solenoid 41, and oil is supplied to the supply port 4a through a branch oil passage 14b that branches from the high-pressure oil passage 14. The OCV 4 receives the oil supplied to the supply port 4a from the control port 4b to the control oil passage 40 (as shown in FIG. 2), and conversely receives the oil from the control oil passage 40 to the control port 4b. , The state is switched to the state of discharging from the drain port 4c (shown in FIG. 1).

  The control hydraulic pressure is adjusted by the OCV 4 and the hydraulic pressure in the control space TC is increased or decreased to adjust the pressing force acting on the arm portion 33a so that the pressing force and the pressing force of the coil spring 34 are balanced. Accordingly, the position of the arm portion 33a is determined. Thereby, the position of the adjustment ring 33 can be changed between the state of the maximum pump capacity shown in FIG. 1 and the state of the minimum pump capacity shown in FIG.

-ECU-
Adjustment of the pump displacement by the operation of the displacement variable mechanism as described above is performed by the ECU 100 for engine control. The ECU 100 according to the present embodiment is a publicly known unit including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, and the like. As schematically shown in FIGS. 1 and 2, the ECU 100 is connected to various sensors such as a crank angle sensor 101, an air flow sensor 102, a water temperature sensor 103, an oil temperature sensor 104, and a hydraulic sensor 105 of the engine 1.

  In the present embodiment, ECU 100 is also connected to an oil level sensor 106 that measures the oil level of the oil stored in oil pan 11. The oil level sensor 106 outputs a signal that continuously changes in accordance with the change in the oil level. The ECU 100 is also connected to an electric throttle valve 16 disposed in the intake passage of the engine 1 and a MIL lamp (Malfunction Indicator Lamp) 17 disposed in the passenger compartment of the automobile.

  The ECU 100 executes various control programs related to the operation of the engine 1 based on signals input from the various sensors 101 to 106, and operates the capacity variable mechanism to change the capacity of the oil pump 3. The oil pressure of the oil supply system 2 is controlled. That is, basically, the command value to the OCV 4 is changed according to the load factor of the engine 1 and the engine speed, and when the load factor is high, the pump capacity is increased, while when the load factor is low, it is decreased. Since the rotational speed of the oil pump 3 is the same as the engine rotational speed, the oil discharge amount naturally increases as the engine rotational speed increases.

  As an example, FIG. 3 shows the relationship between the command value (OCV current value) from the ECU 100 to the OCV 4, the engine speed, and the discharge pressure of the oil pump 3. From this figure, it can be seen that the pump discharge pressure can be adjusted by changing the pump capacity by controlling the OCV current value. In other words, if the engine speed is higher than a certain level, the pump discharge pressure can be maintained regardless of the change, and the hydraulic pressure of the main gallery 20 of the oil supply system 2 can be suitably controlled.

  Therefore, the ECU 100 determines the target hydraulic pressure according to, for example, the load factor and the rotational speed of the engine 1 and reduces the hydraulic pressure when the load factor and the rotational speed are low, thereby reducing the power loss of the engine 1 due to the driving of the oil pump 3 ( (Pump drive loss) is reduced. Specifically, as basic control of the hydraulic pressure, a signal from the hydraulic pressure sensor 105 is fed back, and the pump capacity is changed according to the deviation of the detected hydraulic pressure (the detected hydraulic pressure value by the hydraulic pressure sensor 105) from the target hydraulic pressure. The oil pressure of the gallery 20 is converged to the target oil pressure.

  Further, the ECU 100 switches the OSV 5 to either the supply state or the shut-off state according to the temperature of the engine 1 or the operating state. For example, the oil jet from the piston jet nozzle 15 is stopped by switching the OSV 5 to the shut-off position after cold start or the like to shut off the oil flow. Thereby, warm-up of the engine 1 can be promoted. On the other hand, after the warm-up is completed, the OSV 5 is switched to the supply position in a predetermined operation region (see FIG. 5) described in detail later, and oil is injected from the piston jet nozzle 15 toward the piston. Thereby, a piston can be cooled effectively.

-Basic processing of hydraulic control-
Hereinafter, first, basic processing related to hydraulic control of the engine 1 of the present embodiment will be specifically described with reference to FIG. This shows the basic flow of processing for adjusting the hydraulic pressure of the oil supply system 2 by adjusting the pump capacity as described above (main routine of hydraulic control). This routine is executed by the ECU 100 during the operation of the engine 1. Are repeatedly executed at a predetermined timing. This routine corresponds to basic control for controlling the hydraulic pressure according to the operating state of the engine 1.

  In step ST101 after the start of the flow of FIG. 4, various types of information representing the operating state of the engine 1 are acquired. For example, the engine speed is calculated from a signal from the crank angle sensor 101, the intake air amount is calculated from a signal from the air flow sensor 102, and the load of the engine 1 is calculated from the engine rotational speed and the intake air amount (may be an accelerator operation amount). Calculate the rate. Further, the water temperature, oil temperature, and oil pressure of the engine 1 are detected by signals from the water temperature sensor 103, the oil temperature sensor 104, and the oil pressure sensor 105.

  Subsequently, in step ST102, based on the load factor, the engine speed, etc., that is, based on the operating state of the engine 1, a reference value of the oil pressure of the main gallery 20 (target oil pressure) with reference to a known map (not shown). ) Is calculated. In step ST103, feedback control calculation is performed so that the hydraulic pressure detected by the hydraulic sensor 105 becomes the target hydraulic pressure. That is, a deviation between the detected hydraulic pressure and the target hydraulic pressure is calculated, and a target value of the pump capacity is calculated so that the detected hydraulic pressure converges on the target hydraulic pressure according to the PID rule or the like.

  In step ST104, a control oil pressure to be supplied to the control space TC of the oil pump 3 is calculated based on the target value of the pump capacity, and a command for operating the spool 42 so that the OCV 4 outputs the control oil pressure. A signal, that is, an OCV current value is calculated. By outputting this command signal from the ECU 100 to the OCV 4, the capacity of the oil pump 3 is suitably controlled, and the hydraulic pressure of the main gallery 20 gradually converges to the target hydraulic pressure.

  The correspondence relationship of the parameters such as the pump displacement, the control hydraulic pressure, and the OCV current value is preliminarily adapted by experiments and simulations and stored as a map in the ROM of the ECU 100. In step ST104, The OCV current value for realizing the target pump capacity is calculated with reference to the map. Also, parameter correspondences can be set as calculation formulas instead of maps.

-OSV control and fault diagnosis-
As described above, the ECU 100 switches the OSV 5 to either the supply or shut-off position according to the operating state of the engine 1 after the warm-up is completed, and causes the piston jet nozzle 15 to inject or stop the oil. Specifically, as shown by hatching in the oil level height map of FIG. 5 as an example, in an operation range (hereinafter referred to as jet injection region) of medium load or high load and medium rotation or high rotation, OSV5 Is switched to the supply position, and oil is injected from the piston jet nozzle 15. Thereby, a piston can be cooled efficiently.

  On the other hand, even after warm-up, in a light load or low-rotation jet stop region (operating region other than the jet injection region), the OSV 5 is switched to the shut-off position to stop oil injection from the piston jet nozzle 15. . That is, when it is not necessary to cool the piston with oil in an operation state with a low heat load, the oil flow rate in the oil supply system 2 can be reduced and the driving load of the oil pump 3 can be reduced. Thus, the ECU 100 constitutes a switching valve control means by controlling the OSV 5 by switching between supply and cutoff.

  By the way, for example, when the electromagnetic solenoid 51 of the OSV 5 breaks down or a foreign object is caught and the spool 52 malfunctions, the OSV 5 may remain switched to the shut-off position (closed failure). In this case, oil may not be injected from the piston jet nozzle 15 even in the jet injection region, and the piston may be overheated. On the other hand, if the OSV 5 remains switched to the supply position (open failure), oil is injected into the piston even after a cold start, and warm-up cannot be promoted.

  Regarding such a failure of the OSV 5, it is conceivable to switch the OSV 5 to either supply or shut-off in a predetermined state and determine whether or not the OSV 5 has failed from the change in the detected hydraulic pressure. However, in the present embodiment, since the hydraulic pressure is feedback-controlled using the variable displacement oil pump 3 as described above, the detected hydraulic pressure is immediately restored even if it temporarily changes with the operation of the OSV 5. Will return to. Therefore, it is difficult to determine a failure of the OSV 5 based on the change in the detected hydraulic pressure.

  Therefore, in the present embodiment, as will be described below, paying attention to the oil level height of the oil stored in the oil pan 11, the oil level height in the oil pan 11 is the reference oil during the operation of the engine 1. The OSV 5 failure is determined based on a large deviation from the surface height by a predetermined amount or more. That is, the oil level in the oil pan 11 varies depending on the amount of oil discharged by the oil pump 3 (that is, the amount of suction from the oil pan 11). Becomes lower, and further decreases as the engine speed increases.

  Further, in the present embodiment, since the pump displacement is controlled as described above, the higher the load factor of the engine 1, the greater the discharge amount of the oil pump 3 and the lower the oil level accordingly. Considering such a change in the oil level, as shown in an example in FIG. 5, the normal oil level that changes according to the load factor and engine speed of the engine 1 after the completion of warm-up is set. Investigate in advance by experiments and simulations, and set as a reference oil level height map. In this map, the reference oil level height decreases as the engine speed increases, and decreases as the load factor increases.

  Further, the reference oil level height is different between the jet injection region and the jet stop region. In the jet injection region shown with hatching in FIG. 5, the OSV 5 is at the supply position and the oil is injected from the piston jet nozzle 15, so that the discharge amount of the oil pump 3 increases correspondingly, as shown by the phantom line. Compared with the case where the characteristics of the jet stop region are extended as they are, the reference oil level is lower. On the contrary, in the jet stop region, the OSV 5 is in the shut-off position and the discharge amount of the oil pump 3 is reduced, so that the reference oil surface is compared with the case where the characteristics of the jet injection region are extended as shown by the phantom line. The height becomes higher.

  And in this Embodiment, compared with the reference | standard oil level height set to the oil level height map like FIG. 5, in the jet injection area | region, the oil level height is more than predetermined and is higher than a reference | standard oil level height. If it is higher, it is determined that the OSV 5 is in a closed failure with the shut-off position. Further, if the oil level height is not less than a predetermined level and lower than the reference oil level height in the jet stop region, it is determined that the OSV 5 is in an open failure with the supply position maintained.

  Hereinafter, the failure diagnosis of the OSV 5 as described above will be specifically described with reference to the flowchart of FIG. The routine shown in this flow is started at a predetermined timing after the engine 1 is started. First, in step ST201 after the start, data such as the load factor of the engine 1, the engine speed, and the oil temperature are read. Note that the load factor and the engine speed are calculated in the ECU 100 for operation control of the engine 1 and stored in the RAM as described above.

  Subsequently, in step ST202, it is determined whether or not the engine 1 is in a warm idle state. That is, if the oil temperature (which may be the engine water temperature) is equal to or higher than a predetermined temperature, the load factor of the engine 1 is equal to or lower than the predetermined value, and the engine speed is within a predetermined idle speed range, Affirmative determination (YES). On the other hand, if any one of the conditions is not satisfied, a negative determination (NO) is made, and the process returns to step ST201. That is, it waits until it becomes a warm idle state.

  If an affirmative determination (YES) is made that the engine is warm idle, the oil level in the oil pan 11 is stabilized, and the process proceeds to step ST203 to learn the initial value of the oil level (initial oil level). Learning). That is, the reference oil level height (shown as OL0 in FIG. 5) corresponding to the current operating state of the engine 1 is read from the oil level height map of FIG. The difference from the surface height is stored as a learning value.

  The learning value stored in this manner calibrates the reference oil level height set in the oil level map in FIG. 5 in consideration of the variation in the amount of oil injected into the oil pan 11 by the user of the automobile. Is to do. If the injected oil is small, the oil level in the oil pan 11 is lowered by that amount. Therefore, the learning value may be subtracted from the reference oil level height set in the oil level height map. On the contrary, if the amount of oil is large, the oil level becomes higher by that amount, so the learning value may be added to the reference oil level height.

  In step ST204 after the initial oil level learning is performed, the reference oil level height corresponding to the current operation state is read from the oil level height map of FIG. Calculate the surface height. At this time, the operating state of the engine 1 is not necessarily idle, but the reference oil level height is set in the oil level height map of FIG. 5 according to the load factor of the engine 1 and the engine speed. The reference oil level height in the current operating state of the engine 1 can be calculated.

  Subsequently, in step ST205, the actual oil level in the oil pan 11 is measured by a signal from the oil level sensor 106, and in step ST206, the measured oil level is the reference oil level height (step It is determined whether or not the value is equal to or higher than the first threshold value than the value calculated in ST204. The first threshold value is set in advance by experiments or the like so that a change in the oil level due to a closed failure of the OSV 5 can be distinguished from a normal oil level height variation.

  If the measured oil level is lower than the sum of the reference oil level and the first threshold, a negative determination (NO) is made in step ST206 and the process proceeds to step ST210 described later. On the other hand, if the measured oil level is equal to or higher than the reference oil level plus the first threshold value, an affirmative determination (YES) is made in step ST206 and the process proceeds to step ST207. Is determined to be in the jet injection region described above with reference to FIG.

  If this determination is negative (NO), the process returns to step ST204. On the other hand, if an affirmative determination (YES) is made that the engine 1 is in the jet injection region, the process proceeds to step ST208, where it is determined that the OSV5 is closed. In the following step ST209, the opening of the throttle valve 16 is limited and the MIL lamp 17 is turned on to issue a warning to the vehicle occupant, and then the control is ended (END).

  That is, if the oil level in the oil pan 11 is higher than the reference oil level by a predetermined level or more in spite of being in the jet injection region, it is determined that the OSV 5 is closed and an alarm is issued. At the same time, fail-safe processing is performed to limit engine output. Thereby, it can prevent that a piston overheats.

  On the other hand, in step ST210, which has proceeded with a negative determination (NO) that the oil level is not so high in step ST206, the oil level height measured by the oil level sensor 106 is now the second. It is determined whether or not the oil level is lower than the reference oil level height and lower than the reference oil level height (that is, the oil level height is lower than the reference oil level height and the difference between them is equal to or higher than the second threshold value). The second threshold value is also set in advance by experiments or the like so that a change in the oil level due to an open failure of the OSV 5 can be distinguished from a normal oil level height variation.

  If the oil level in ST210 is higher than the value obtained by subtracting the second threshold value from the reference oil level, a negative determination (NO) is made and the process returns to step ST204. On the other hand, if the oil level is equal to or less than the value obtained by subtracting the second threshold value from the reference oil level, an affirmative determination (YES) is made and the process proceeds to step ST211. Here, it is determined whether or not the operating state of the engine 1 is in the jet stop region. If the determination is negative (NO) if it is not in the jet stop region, the process returns to step ST204.

  That is, even if the oil level in the oil pan 11 is not so low or considerably low, if it is not in the jet stop region, it is not determined that the OSV 5 has failed, and the steps ST204 to ST207, ST210, ST211 are not performed. Repeat the above procedure. This is repeated at predetermined time intervals, for example, 10 seconds.

  On the other hand, if an affirmative determination (YES) is made in step ST211 that the operating state of the engine 1 is in the jet stop region, the process proceeds to step ST212, where it is determined that the OSV5 is open, and in step ST213, the MIL lamp 17 is turned on. To end the control (end). That is, if the oil level in the oil pan 11 is lower than the reference oil level by a predetermined level or more in spite of the jet stop region, it is determined that the OSV 5 is open and the fail safe Process.

  In this case, the OSV 5 cannot be switched to the shut-off position, and the oil is still injected from the piston jet nozzle 15, so that the warm-up of the engine 1 after the cold start is delayed or the fuel consumption increases due to an increase in heat loss. However, there is no problem of piston overheating. Therefore, as a fail-safe process, only a warning is issued, and output restriction of the engine 1 is not performed, so that drivability is ensured.

  By executing steps ST206 to ST208 of the flow of FIG. 6, the ECU 100 causes the oil level height measured by the oil level sensor 106 when the OSV 5 is controlled to the supply position in accordance with the operating state of the engine 1. If it is higher than the reference oil level by a first threshold value or higher, a failure determination means for determining that a closed failure has occurred. Further, by executing step ST209, the ECU 100 constitutes a fail-safe means that issues an alarm and limits the output of the engine 1 when it is determined that the OSV 5 is closed.

  In the present embodiment, the failure determination means executes the steps ST210 to ST212 of the flow so that the oil level height measured by the oil level sensor 106 when the OSV 5 is controlled to the cutoff position is a reference. If it is lower than the oil level and the difference between the two is equal to or greater than the second threshold value, it is determined that an open failure has occurred.

  Further, the fail-safe means issues an alarm when it is determined that the OSV 5 is open by executing step ST213 of the flow, while the output of the engine 1 is not limited. Further, by executing steps ST202 and ST203 in the flow of FIG. 6, the ECU 100 constitutes oil level height calibration means for calibrating the reference oil level height in a warm idle state of the engine 1.

  As described above, according to the present embodiment, during the operation of the engine 1, the OSV 5 is controlled according to the operation state, and in the jet injection region, by the oil injected from the piston jet nozzle 15, The piston is cooled efficiently. On the other hand, for example, in the jet stop region after the cold start of the engine 1 and after the warm-up, the oil is not injected from the piston jet nozzle 15 and the warm-up is promoted after the cold start, and after the warm-up. If so, fuel efficiency can be improved by reducing heat loss and driving loss of the oil pump 3.

  If the oil level in the oil pan 11 measured by the oil level sensor 106 in the jet injection region is higher than the reference oil level by a predetermined level or more, the closed failure with the OSV 5 in the shut-off position remains. Can be determined. In response to this, a warning is given to the vehicle occupant and a fail-safe process that limits the output of the engine 1 is performed to prevent overheating of the piston even if oil injection from the piston jet nozzle 15 is not performed. it can.

  On the other hand, if the oil level height measured by the oil level sensor 106 in the jet stop region is equal to or higher than the second threshold value and lower than the reference oil level height, it is determined that the OSV 5 remains in the supply position and is an open failure. it can. In this case, since the problem of piston overheating does not occur, the fail-safe process for issuing a warning to the vehicle occupant is performed, and the drivability is ensured without limiting the output of the engine 1.

  Further, in the present embodiment, the failure is determined while performing the switching control of the OSV 5 according to the operating state of the engine 1 as described above, so that the opportunity for determining the failure is sufficiently increased. The effectiveness is guaranteed. That is, for example, it is conceivable that the OSV 5 is forcibly set in the shut-off position in the jet injection region, and an open failure of the OSV 5 is determined from the change in the oil level height that occurs at this time. This may cause the piston to overheat, which is not preferable.

  On the other hand, when the OSV 5 is forcibly set to the supply position in the jet stop region, a problem such as overheating of the piston does not occur, but in this case, it is difficult to make a determination because the oil level is difficult to change. There is a real situation. Specifically, in the low rotation region, which is the jet stop region, the oil pressure is controlled to be low, so even if the OSV 5 is in the supply position, the discharge amount of the oil pump 3 does not increase so much and the change in the oil level does not increase. .

  Further, in the light load region of medium rotation or high rotation that is also the jet stop region, the frequency of the oil level changes because the frequency of the engine 1 being operated in this operation region is very low during the operation of the automobile. It is rare for the engine 1 to be in a light load state of medium to high rotation continuously for a sufficient time (for example, about 10 seconds). Therefore, it is difficult to determine the oil level by forcibly setting the OSV 5 to the supply position in this operating state. It is preferable to determine.

-Other embodiments-
The description of the above-described embodiment is merely an example, and is not intended to limit the configuration or application of the present invention. For example, in the above-described embodiment, as shown in steps ST202 and ST203 of the flow in FIG. 6, the initial oil level learning is performed in the warm idle state of the engine 1, but this is not a limitation. Even if other than the above, the oil level height can be learned in the steady operation state. It is also possible not to perform initial oil level learning.

  In the above embodiment, the OSV5 open failure is determined in steps ST210 to ST213 in the flow of FIG. 6, but this determination is not made, and only the determination of the closed failure in steps ST206 to ST209 is performed. It may be. This is because in the case of a closed failure, the piston may be overheated, and it is highly important to make a determination during operation of the engine 1.

  Further, the oil supply system 2 of the engine 1 in the above embodiment supplies oil to the piston jet nozzle 15 through a branch passage 14 a that branches from the high-pressure oil passage 14 that extends from the oil pump 3 to the main gallery 20. However, the present invention is not limited to this, and oil may be supplied to the piston jet nozzle 15 through a passage branched from the main gallery 20.

  The present invention can determine a failure of a switching valve (OSV or the like) that switches between supplying and shutting off oil to the piston jet nozzle even when the oil pressure of the oil supply system of the engine is fed back. It is highly effective when applied.

DESCRIPTION OF SYMBOLS 1 Engine 2 Oil supply system 3 Oil pump 33 Adjustment ring (Capacity variable mechanism: Hydraulic pressure variable means)
34 Coil spring (capacity variable mechanism: hydraulic variable means)
5 OSV (switching valve)
11 Oil pan 15 Piston jet nozzle 100 ECU (switching valve control means, failure determination means, fail safe means, oil level height calibration means)
105 Oil pressure sensor 106 Oil level sensor TC Control space (capacity variable mechanism: oil pressure variable means)

Claims (7)

Oil pressure variable means capable of changing the oil pressure of the oil supply system;
A switching valve that is switched to supply or shut off oil to a piston jet nozzle that injects oil toward the piston;
Applied to an engine having an oil level sensor capable of measuring the oil level of oil stored in an oil pan,
A hydraulic control device configured to perform feedback control of hydraulic pressure by the hydraulic pressure variable unit according to a detected value of hydraulic pressure by a hydraulic sensor provided in the oil supply system;
A switching valve control means for switching the switching valve to either a supply state or a cutoff state;
Failure determination means for determining failure of the switching valve based on a difference between an oil level height measured by the oil level sensor and a reference oil level height set according to a state of the switching valve. A hydraulic control device characterized by that. The hydraulic control device according to claim 1,
The failure determination means is configured such that when the switching valve control means controls the switching valve to be in a supply state, the oil level height measured by the oil level sensor is higher than a reference oil level height, and the difference between the two. If is equal to or greater than a first threshold, the hydraulic control device determines that the switching valve is in a closed failure. In the hydraulic control device according to claim 1 or 2,
The failure determination means is configured such that when the switching valve control means controls the switching valve to be in a shut-off state, the oil level height measured by the oil level sensor is lower than the reference oil level height, and the difference between the two. Is a second threshold value, the hydraulic control device determines that the switching valve has an open failure. In the hydraulic control device according to claim 2,
A hydraulic control device comprising fail-safe means for issuing an alarm and limiting engine output when it is determined by the failure determination means that the switching valve is closed. The hydraulic control device according to claim 4,
The fail-safe means is a hydraulic control device that issues an alarm and does not limit the engine output when the failure determination means determines that the switching valve is open failure. In the hydraulic control device according to any one of claims 1 to 5,
The switching valve control means is a hydraulic control device that controls the switching valve to be in a supply state or a cutoff state in accordance with an engine temperature state and an operating state. In the hydraulic control device according to any one of claims 1 to 6,
A hydraulic control device comprising oil level height calibration means for calibrating the reference oil level height in a predetermined operating state of an engine.

Images