JP5704106B2 - Lubricating device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine lubrication device, and more particularly to an internal combustion engine lubrication device including an oil jet mechanism that lubricates and cools a piston.

  As a conventional technique, for example, as disclosed in Japanese Patent Application Laid-Open No. 2012-2216, a lubrication device for an internal combustion engine including an oil jet mechanism that lubricates and cools a piston is known. In the prior art, when the coolant temperature is equal to or lower than a predetermined value as in cold start, the hydraulic pressure supplied to the oil jet is set low, and the oil injection from the oil jet to the piston is stopped. Thereby, in the prior art, at the time of cold start, oil adheres to the piston and the piston is prevented from being cooled.

JP 2012-2216 A JP 2008-38705 A JP 2010-216266 A

  In the prior art described above, the oil jet is controlled (stopped) in order to suppress the cooling of the piston at the time of starting. However, in this case, the temperature of the injection nozzle rises with the oil jet stopped as time elapses after starting. When the temperature of the spray nozzle becomes high, there is a problem that oil becomes sludge in the spray nozzle and the nozzle is easily clogged. This problem is not limited at the time of starting, but can occur during cold operation.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to prevent clogging of the oil jet while suppressing cooling of the piston by the oil jet during cold operation. It is an object of the present invention to provide a lubricating device for an internal combustion engine that can be used.

According to a first aspect of the present invention, there is provided an oil jet that injects oil toward a piston of an internal combustion engine;
An oil pump for supplying oil to the oil jet;
Oil supply pressure variable means for variably setting the supply pressure of oil supplied from the oil pump to the oil jet;
During cold operation of the internal combustion engine, the oil supply pressure variable means is driven while oil is injected from the oil jet to set the supply pressure of the oil to a supply pressure at which the oil does not reach the piston. To do.

  According to a second aspect of the present invention, there is provided a failure diagnosis means for performing a failure diagnosis of an oil injection system including the oil jet based on a change in an engine speed when the operation state of the oil jet is controlled on and off during idle operation. Prepare.

  According to a third aspect of the present invention, when the tip temperature of the oil jet exceeds an allowable temperature, the oil injection amount of the oil jet is increased, and the increased state is continued until the tip temperature falls below the allowable temperature. Suppression control means is provided.

  According to a fourth aspect of the present invention, there is provided an oil jet cleaning control unit that increases an oil injection amount of the oil jet when a cleaning request for the oil jet is generated, compared to a case where the cleaning request is not generated.

  According to the first invention, the oil injection suppression means can suppress the supply pressure (injection pressure) of the oil to the extent that the oil does not reach the piston while injecting the oil from the oil jet. Thereby, it is possible to prevent the piston from being cooled by the oil injected from the oil jet during the cold operation, and to improve the warm-up efficiency. Further, it is possible to prevent oil staying in the jet nozzle of the oil jet from becoming sludge and to suppress clogging of the oil jet.

  According to the second invention, the failure of the oil injection system can be easily performed based on the change in the engine speed when the operation state of the oil jet is switched without using a special failure detection mechanism or sensor. Can be diagnosed. Thereby, simplification of the system and cost reduction can be promoted. In addition, after starting, by first performing failure diagnosis during idle operation, it is possible to detect a failure of the oil injection system before high load operation, etc., and the load increases in the failure state. A situation in which other failures occur in a chain can be avoided.

  According to the third invention, the clogging suppression control means can continue the increasing state of the oil injection amount until the tip temperature becomes equal to or lower than the allowable temperature when the tip temperature of the oil jet exceeds the allowable temperature. it can. Thereby, for example, even when high-load operation is frequently performed, the heat resistance of the oil jet can be improved.

  According to the fourth aspect of the invention, the oil jet cleaning control means can increase the oil injection amount when a request for cleaning the oil jet occurs due to failure diagnosis or the like. Thereby, even when there is no cooling request for the piston, it is possible to suppress the oil from becoming sludge inside the oil jet and to prevent clogging of the oil jet.

It is a whole block diagram for demonstrating the system configuration | structure of Embodiment 1 of this invention. 3 is a timing chart showing oil injection suppression control, failure diagnosis control, clogging suppression control, and oil jet cleaning control according to Embodiment 1 of the present invention.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall configuration diagram for explaining a system configuration according to the first embodiment of the present invention. The system of the present embodiment includes an engine 10 as an internal combustion engine, and a combustion chamber 14 is formed by a piston 12 in each cylinder of the engine 10. The piston 12 reciprocates as the combustion chamber 14 expands and contracts, and is connected to the crankshaft 16. The engine 10 also includes an intake passage 18 that sucks intake air into each cylinder, and an exhaust passage 20 through which exhaust gas is discharged from each cylinder. The intake passage 18 is provided with an electronically controlled throttle valve 22 for adjusting the amount of intake air, and the exhaust passage 20 is provided with a catalyst 24 for purifying exhaust gas. Each cylinder has a fuel injection valve 26 for injecting fuel into the intake port, an ignition plug 28 for igniting the air-fuel mixture in the cylinder, an intake valve 30 for opening and closing the intake port, and an exhaust valve for opening and closing the exhaust port. 32 is provided.

  The engine 10 also includes an oil pan 40 in which lubricating oil (oil) is stored, and a lubrication system that lubricates each part of the engine using the oil in the oil pan 40. The lubrication system includes an oil jet 42 that injects oil toward the piston 12, an oil pump 44 that supplies oil sucked from the oil pan 40 to the oil jet 42, a flow control valve 46 such as an electromagnetic valve, and a relief valve. 48 is included. Here, the amount of oil injected from the injection nozzle of the oil jet 42 changes according to the oil supply pressure. Further, as the oil pump 44, for example, a mechanical pump driven using the output of the engine 10 is used.

  The flow rate control valve 46 variably sets the supply flow rate and supply pressure of the oil supplied from the oil pump 44 to the oil jet 42, and constitutes the oil supply pressure variable means of the present embodiment. In the present invention, for example, a variable displacement oil pump 44 is employed as the oil supply pressure varying means, and the flow rate control valve 46 may not be used. Further, the relief valve 48 returns excess oil on the discharge side of the oil pump 44 to the suction side of the pump. When the flow control valve 46 is fully closed, the oil discharged from the oil pump 44 is returned to the suction side via the relief valve 48, and the oil injection operation by the oil jet 42 is stopped. In the present invention, for example, the relief valve 48 or the oil pump 44 having a function similar to that of the relief valve 48 is employed, and the single relief valve 48 may not be used.

  Next, a system control system will be described. The system according to the present embodiment includes a sensor system including various sensors necessary for controlling the vehicle and the engine, and an ECU (Electronic Control Unit) 60 that controls the operating state of the engine 10. First, the sensor system will be described. The crank angle sensor 50 outputs a signal synchronized with the rotation of the crankshaft 16, and the air flow sensor 52 detects the intake air amount of the engine. The water temperature sensor 54 detects the water temperature of the engine cooling water, and the oil temperature sensor 56 detects the temperature of the oil in the oil pan 40. In addition, the sensor system includes, for example, an air-fuel ratio sensor that detects the exhaust air-fuel ratio, a throttle sensor that detects the throttle opening, an accelerator sensor that detects the accelerator operation amount of the driver, and the like.

  The ECU 60 is configured by an arithmetic processing device including a storage circuit such as a ROM and a RAM and an input / output port. Each sensor of the sensor system is connected to the input side of the ECU 60. Various actuators including a throttle valve 22, a fuel injection valve 26, a spark plug 28, a flow control valve 46, and the like are connected to the output side of the ECU 60. The ECU 60 controls the operation of the engine by driving each actuator based on the engine operation information detected by the sensor system. Specifically, the engine speed (engine speed) and the crank angle are detected based on the output of the crank angle sensor 38, and the load is determined based on the intake air amount detected by the airflow sensor 52 and the engine speed. calculate. Further, the fuel injection amount is calculated based on the engine speed, load, water temperature, etc., and the fuel injection timing and ignition timing are determined based on the crank angle. In each cylinder, the fuel injection valve 26 is driven when the fuel injection timing comes, and the spark plug 28 is driven when the ignition timing comes. Thereby, the air-fuel mixture is combusted in the combustion chamber 14 of each cylinder, and the engine can be operated.

[Features of Embodiment 1]
In the present embodiment, as shown in FIG. 2, oil injection suppression control is executed during cold operation, and the piston 12 is prevented from being cooled by low-temperature oil. Further, if a configuration capable of realizing this control is adopted, the configuration and control of the system are complicated to some extent. In the present embodiment, control for diagnosing a failure in the oil injection system including the oil jet 42 (failure diagnosis control) And control (clogging suppression control and oil jet cleaning control) for preventing failure of the oil jet 42 and the like. FIG. 2 is a timing chart showing oil injection suppression control, failure diagnosis control, clogging suppression control, and oil jet cleaning control. Hereinafter, these controls will be described.

(Oil injection suppression control)
During operation of the engine, the oil pump 44 is driven by the rotation of the crankshaft 16, and oil is supplied from the oil pump 44 to the oil jet 42. Thereby, the oil jet 42 can inject oil toward the back surface side of the piston 12, and can lubricate and cool the piston 12 and its surrounding parts. However, when the oil jet 42 is activated at the time of cold start or the like, the low-temperature oil is sprayed onto the piston 12 to reduce the warm-up efficiency. On the other hand, if the oil jet 42 is stopped at the time of starting, when the temperature rises, the oil in the injection nozzle becomes sludge and clogging occurs.

  For this reason, in this Embodiment, oil injection suppression control is performed at the time of engine cold operation (refer FIG. 2). In the oil injection suppression control, by driving the flow rate control valve 46 to the valve closing side, oil is injected from the oil jet 42 and the oil supply pressure (the oil injection pressure and (Injection amount). According to this control, it is possible to prevent the piston 12 from being cooled by the oil injected from the oil jet 42 and improve the warm-up efficiency. Further, it is possible to prevent the oil remaining in the injection nozzle of the oil jet 42 from becoming sludge and to suppress clogging of the oil jet 42. The oil injection suppression control is particularly effective during cold start, but can be widely applied during cold operation where the piston 12 is not desired to be cooled, including during idle operation.

(Fault diagnosis control)
During idle operation, failure diagnosis control for performing failure diagnosis of the oil injection system is executed. Here, the oil injection system includes at least an oil jet 42, an oil pump 44, a flow rate control valve 46, and a relief valve 48. In the failure diagnosis control, as shown in FIG. 2, it is diagnosed whether or not the oil injection system has failed based on a change in the engine speed when the operation state of the oil jet 42 is controlled to be turned on and off. More specifically, for example, when the oil jet system is in a normal state and the oil jet 42 is stopped (OFF) from the operating state (ON), the engine load decreases accordingly, and the engine speed increases. . When the oil jet 42 is operated from a stopped state, the engine load increases and the engine speed decreases. On the other hand, when the oil injection system is out of order, the engine speed does not change even if the ON-OFF control is executed.

  Therefore, according to this control, failure of the oil injection system can be easily performed based on the presence or absence of a change in the rotational speed when the operation state of the oil jet 42 is switched without using a special failure detection mechanism or sensor. Can be diagnosed. Thereby, simplification of the system and cost reduction can be promoted. In addition, since appropriate processing can be performed when a failure is detected, for example, when the flow control valve 46 fails, oil is sprayed when cold, the piston becomes too cold and exhaust emission deteriorates, or a high load ( When the oil is not injected at a high temperature, it is possible to avoid a situation where the piston cannot be cooled.

  In addition, after starting the engine, it is possible to detect a failure in the oil injection system before high load operation is performed by first performing failure diagnosis during idle operation. Can be executed (for example, oil jet cleaning control described later). Therefore, it is possible to avoid a situation in which another failure occurs in a chain due to an increase in load in a failure state. Further, during idle operation, since there is little disturbance that changes the engine speed other than the ON-OFF control, failure diagnosis control can be performed with high accuracy. In the present embodiment, the operation and stop of the oil jet 42 (execution and stop of oil injection) are realized, for example, by opening and closing the flow rate control valve 46 (ON-OFF control). However, the present invention is not limited to this, and an electromagnetically driven oil pump or the like may be adopted to control the oil pump on and off.

(Clogging suppression control)
When the tip temperature of the oil jet 42 exceeds a predetermined allowable temperature, the oil becomes sludge in the injection nozzle and clogging is likely to occur. Therefore, in this case, the clogging suppression control is executed in which the oil injection amount of the oil jet 42 is increased and the increased state is continued until the tip temperature becomes equal to or lower than the allowable temperature. The clogging suppression control shown in FIG. 2 is a case where the oil injection amount is increased at the start of the high load operation until the tip temperature becomes equal to or lower than the allowable temperature after the end of the high load operation. Is illustrated. In this case, when the high load operation is finished and the tip temperature of the oil jet 42 is equal to or lower than the allowable temperature, the clogging suppression control is finished, and the oil injection amount is returned to the state before the increase.

  Here, the oil injection amount may be automatically increased by increasing the drive rotational speed of the mechanical oil pump 44 at the start of high load operation. For example, the oil injection amount may be a flow control valve 46 or a variable displacement oil. The amount may be increased by control using a pump. Similarly, maintaining the increased state is realized by controlling the flow rate control valve 46 and the variable displacement oil pump. On the other hand, the tip temperature of the oil jet 42 is calculated based on, for example, the oil temperature detected by the oil temperature sensor 56, the duration of the high-load operation, and the allowable temperature is determined by experiments or the like.

  According to the clogging suppression control, even after a high-load operation, when the tip of the oil jet 42 is at a high temperature, the increased amount of oil injection is maintained and the tip is continuously cooled. And the temperature of the tip can be efficiently reduced. Thereby, even when a high load operation is frequently performed, the heat resistance of the oil jet 42 can be improved. In the present invention, the execution timing of the clogging suppression control is not limited to during high load operation (after high load operation). That is, the clogging suppression control may be executed in any operation state in which the tip temperature of the oil jet 42 exceeds the allowable temperature.

(Oil jet cleaning control)
In the oil jet cleaning control, when a cleaning request for the oil jet 42 is generated, the oil injection amount is increased as compared with a case where the cleaning request is not generated, and the inside of the injection nozzle is cleaned. Here, the case where the cleaning request is generated is, for example, a case where a failure of the oil injection system is detected by failure diagnosis control. As shown in FIG. 2, the oil jet cleaning control is realized, for example, by increasing the engine speed by increasing the fuel injection amount and increasing the drive speed of the oil pump 44 during intermediate load operation. The In addition, the oil jet cleaning control increases the opening of the flow control valve 46 when the engine speed increases due to, for example, deceleration operation (use of engine brake) or increases the oil discharge amount in the variable displacement oil pump. You may implement | achieve by doing.

  According to the oil jet cleaning control, even when there is no request for cooling the piston 12, the oil injection amount of the oil jet 42 can be increased and the oil can be prevented from becoming sludge in the injection nozzle. Further, oil that is becoming sludge can be peeled off by a large amount of oil injection and removed. Therefore, clogging of the oil jet 42 can be suppressed, and the operation state can be maintained well.

  In the first embodiment, the oil injection suppression control in FIG. 2 shows a specific example of the oil injection suppression means in claim 1, and the failure diagnosis control shows a specific example of the failure diagnosis means in claim 2. . Further, the clogging suppression control in FIG. 2 shows a specific example of the clogging suppression control means in claim 3, and the oil jet cleaning control shows a specific example of the oil jet cleaning control means in claim 4.

10 Engine (Internal combustion engine)
12 piston 14 combustion chamber 16 crankshaft 18 intake passage 20 exhaust passage 22 throttle valve 24 catalyst 26 fuel injection valve 28 spark plug 30 intake valve 32 exhaust valve 40 oil pan 42 oil jet 44 oil pump 46 flow control valve (oil supply pressure variable) means)
48 Relief valve 50 Crank angle sensor 52 Air flow sensor 54 Water temperature sensor 56 Oil temperature sensor 60 ECU

Claims (4)

An oil jet that injects oil toward the piston of the internal combustion engine;
An oil pump for supplying oil to the oil jet;
Oil supply pressure variable means for variably setting the supply pressure of oil supplied from the oil pump to the oil jet;
During cold operation of the internal combustion engine, the oil supply pressure variable means is driven while oil is injected from the oil jet to set the supply pressure of the oil to a supply pressure at which the oil does not reach the piston. A lubricating device for an internal combustion engine.   Failure diagnosis of an oil injection system including at least the oil jet, the oil pump, and the oil supply pressure varying means based on a change in engine speed when the operation state of the oil jet is controlled on and off during idle operation. The lubricating device for an internal combustion engine according to claim 1, further comprising failure diagnosis means for performing the operation.   Clogging suppression control means for increasing the oil injection amount of the oil jet when the tip temperature of the oil jet exceeds a permissible temperature and continuing the increased state until the tip temperature falls below the permissible temperature. The internal combustion engine lubrication device according to claim 1 or 2.   The oil jet cleaning control means for increasing the oil injection amount of the oil jet when the cleaning request for the oil jet is generated as compared with the case where the cleaning request is not generated is provided. The internal combustion engine lubricating device according to any one of the preceding claims.

Images