Control device for oil supply mechanism

Abstract

To suppress the cost increase caused by the increase in the number of sensors. [Solution] The control device for the oil supply mechanism is applied to an oil supply mechanism comprising a main gallery 51, a sub-gallery, an oil jet capable of injecting oil onto a piston, a hydraulic pressure sensor for detecting hydraulic pressure in the main gallery 51, and an on-off valve capable of switching the sub-gallery to an open or closed state. The control device is capable of performing an injection process that performs oil injection from the oil jet by switching the on-off valve to an open state when the operating state of the internal combustion engine is in a specific operating state, and a determination process that switches the on-off valve to an open state when the operating state of the internal combustion engine is not in a specific operating state, and determines whether or not the on-off valve is stuck based on fluctuations in hydraulic pressure detected by the hydraulic pressure sensor before and after the on-off valve is switched to an open state.

Description

TECHNICAL FIELD

[0001] The present invention relates to a control device for an oil supply mechanism. BACKGROUND ART

[0002] Patent Document 1 discloses an oil jet that injects oil toward a piston of an internal combustion engine. Patent Document 1 also proposes a technique for controlling opening and closing of an oil jet in accordance with an operating state of an internal combustion engine. Specifically, an oil control valve that switches whether to supply oil to an oil jet gallery, which is a sub-gallery connected to the oil jet, is attached to an inlet of the oil jet gallery. PRIOR ART DOCUMENT PATENT DOCUMENT

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2021-032104 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0004] However, when the oil control valve is stuck closed, there is a problem that oil cannot be ejected from the oil jet. In this case, the piston temperature rises, which may cause problems such as seizing. To avoid this problem, it is conceivable to attach an oil pressure sensor to the sub-gallery. With this configuration, closed sticking of the oil control valve can be detected based on a change in oil pressure at the timing when the oil jet is brought into an open state.

[0005] However, in this case, it is necessary to attach an oil pressure sensor to the sub-gallery in addition to a conventionally existing oil pressure sensor for a main gallery. Therefore, there is also a problem that the number of sensors increases and the cost rises. MEANS FOR SOLVING THE PROBLEM

[0006] The control device for an oil supply mechanism to solve the above problems is applied to an oil supply mechanism comprising: a main gallery through which oil pumped by an oil pump flows; a sub-gallery branching off from the main gallery; an oil jet connected to the sub-gallery and capable of injecting oil into the piston of an internal combustion engine; a hydraulic pressure sensor for detecting the hydraulic pressure in the main gallery; and an on-off valve capable of switching the sub-gallery to an open or closed state. The control device is capable of performing an injection process in which oil is injected from the oil jet by switching the on-off valve to an open state when the operating state of the internal combustion engine is in a predetermined specific operating state; and a determination process in which the on-off valve is switched to an open state when the operating state of the internal combustion engine is not in the specific operating state, and determines whether the on-off valve is stuck based on fluctuations in hydraulic pressure detected by the hydraulic pressure sensor before and after the on-off valve is switched to an open state. [Effects of the Invention]

[0007] According to the present invention, since hydraulic sensors only need to be installed in the main gallery, the cost increase caused by an increase in the number of sensors can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing a schematic configuration of an internal combustion engine equipped with a control device for the oil supply mechanism of an embodiment. [Figure 2] Figure 2 is a flowchart illustrating the determination process for determining whether or not the oil control valve is stuck in the closed position. [Figure 3] Figure 3 is a flowchart illustrating the determination process for determining whether or not the oil control valve is stuck in the closed position in a modified example of the same embodiment. [Modes for carrying out the invention]

[0009] The following describes one embodiment of the control device for the oil supply mechanism. <Configuration of internal combustion engine 10> As shown in Figure 1, the vehicle is equipped with an internal combustion engine 10. The internal combustion engine 10 in this embodiment is a gasoline engine. The internal combustion engine 10 has a plurality of cylinders 21 (only one is shown in Figure 1). A piston 22 reciprocates within each cylinder 21. Each piston 22 is connected to a crankshaft 24 via a connecting rod 23. The area above the piston 22 within the cylinder 21 is a combustion chamber 25. In each combustion chamber 25, a mixture containing intake air introduced through an intake passage 26 and fuel injected from a fuel injector 27 is burned. The exhaust generated in each combustion chamber 25 by the combustion of this mixture is discharged into an exhaust passage 28.

[0010] <Configuration of the oil supply mechanism 40> The vehicle is also equipped with an oil supply mechanism 40 that operates to circulate oil within the internal combustion engine 10. The oil supply mechanism 40 comprises an oil pump 41, a main gallery 51, and a sub-gallery 61. The oil pump 41 draws oil from the oil pan of the internal combustion engine 10 and supplies the drawn oil to the main gallery 51 and the sub-gallery 61. Oil pumped by the oil pump 41 circulates within the main gallery 51. The main gallery 51, for example, supplies the oil pumped by the oil pump 41 to the crankshaft 24. The main gallery 51 is also fitted with an oil pressure sensor 52 that detects the oil pressure within the main gallery 51.

[0011] The sub-gallery 61 branches off from the downstream side of the hydraulic sensor 52 in the main gallery 51. The sub-gallery 61 supplies oil supplied from the oil pump 41 to the valve train mechanism that controls the opening and closing timing of the intake valve 29 and the exhaust valve 30. The sub-gallery 61 is also equipped with an electromagnetically operated oil control valve 62 (hereinafter referred to as "OCV"). The OCV 62 can switch the sub-gallery 61 between an open state and a closed state.

[0012] Furthermore, an oil jet 63 for cooling the piston 22 is connected to the sub-gallery 61. The oil jet 63 is capable of injecting oil supplied from the oil pump 41 toward the back surface of the piston 22. Specifically, when the OCV 62 is open, oil is supplied from the sub-gallery 61 to the oil jet 63, and oil is injected from the oil jet 63 toward the piston 22. On the other hand, when the OCV 62 is closed, the supply of oil from the sub-gallery 61 to the oil jet 63 is stopped, and therefore oil injection from the oil jet 63 is stopped.

[0013] <Configuration of the control device 70> Next, with reference to Figure 1, the control device 70 of the oil supply mechanism 40 in this embodiment will be described. The vehicle is equipped with the control device 70. The control device 70 controls the OCV 62. The control device 70 has a jet control unit 71 and a sticking determination unit 72. Although the jet control unit 71 and the sticking determination unit 72 are described separately for convenience, they are not configured as independent and separate objects. The jet control unit 71 controls the operation of the oil jet 63 through the control of the OCV 62. Specifically, the jet control unit 71 can perform an injection process that injects oil from the oil jet 63 by switching the OCV 62 to an open state when the operating state of the internal combustion engine 10 is in a predetermined specific operating state. The jet control unit 71 also switches the OCV 62 to an open state when the operating state of the internal combustion engine 10 is not in a specific operating state. At this time, the sticking determination unit 72 causes the hydraulic pressure sensor 52 to detect fluctuations in hydraulic pressure before and after the OCV 62 is switched to an open state. The sticking determination unit 72 can then perform a determination process to determine whether or not the OCV 62 is stuck in the closed position, based on the detected fluctuations in hydraulic pressure.

[0014] In addition, "specific operating conditions" refer to operating conditions that require oil injection from the oil jet 63. Here, the control map of the OCV 62 specifies operating conditions in which the OCV 62 is instructed to open, and operating conditions in which the OCV 62 is not instructed to open, based on ranges such as engine load, engine speed, water temperature, and oil temperature. The above-mentioned "specific operating conditions" correspond to the operating conditions in which the OCV 62 is instructed to open, as shown on the control map.

[0015] <Specific processing steps for the judgment process> As shown in Figure 2, the control device 70 repeatedly executes this routine at predetermined control cycles when the operating state of the internal combustion engine 10 is not a specific operating state, that is, when the OCV 62 is not in an operating state on the OCV 62 control map that does not issue an open valve instruction to the OCV 62.

[0016] When the control device 70 starts this routine, in step S100, it first switches the OCV62 to the open state. That is, the control device 70 deliberately opens the OCV62 even though there is no instruction to open the OCV62 on the control map. In the next step S110, the control device 70 detects the hydraulic pressure in the main gallery 51 using the hydraulic sensor 52.

[0017] In the next step S120, the control device 70 determines whether the hydraulic pressure of the main gallery 51, as detected by the hydraulic pressure sensor 52, has changed by more than a predetermined threshold compared to the hydraulic pressure before switching the OCV 62 to the open state. If the control device 70 determines that the hydraulic pressure of the main gallery 51 has changed by more than the threshold (YES), it proceeds to step S130.

[0018] If the process proceeds to step S130, the control device 70 determines that the OCV62 opens and closes normally. Having determined that the OCV62 is functioning normally, the control device 70 terminates this routine.

[0019] On the other hand, if the control device 70 determines that the amount of fluctuation in the oil pressure in the main gallery 51 is less than the threshold value (NO), it advances the process to step S140. When the process proceeds to step S140, the control device 70 determines that closed sticking, in which the OCV 62 does not switch to the open state, has occurred. In this case, in the next step S150, the control device 70 performs processing to execute fail-safe. Specifically, when the control device 70 determines that closed sticking has occurred in the OCV 62, it notifies the driver of the occurrence of an abnormality (closed sticking) by turning on a warning light (wrench mark) on a display (not shown). Further, when the control device 70 determines that closed sticking of the OCV 62 has occurred, it executes processing to limit the engine load of the internal combustion engine 10. For example, in step S150, the control device 70 sets an upper limit value for the engine load of the internal combustion engine 10, and performs control such that the engine load of the internal combustion engine 10 does not exceed the upper limit value. Thereafter, the control device 70 ends the present routine.

[0020] <Effects of the Present Embodiment> (1) In determining whether the OCV 62, which is capable of switching the sub gallery 61 to an open state or a closed state, is closed and stuck, the oil pressure in the main gallery 51 is detected by an oil pressure sensor 52. The main gallery 51 serves as a starting point for other hydraulically driven components such as the sub gallery 61. For this reason, fluctuations in the oil pressure in the sub gallery 61 branched from the main gallery 51 are indirectly detected based on fluctuations in the oil pressure detected by the oil pressure sensor 52 attached to the main gallery 51. In other words, since it is sufficient to attach the oil pressure sensor 52 only to the main gallery 51, an increase in cost caused by an increase in the number of sensors can be suppressed.

[0021] (2) In the present embodiment, the determination of an abnormality (closed sticking) of the OCV 62 is performed based on fluctuations in the oil pressure detected by the oil pressure sensor 52 before and after switching the OCV 62 to the open state when the engine is not in an operating state that requires oil injection from the oil jet 63. That is, even at a timing when oil injection from the oil jet 63 is unnecessary, closed sticking of the OCV 62 can be determined before a situation where oil injection is actually required.

[0022] (3) Furthermore, if the OCV62 becomes stuck, the hydraulic pressure becomes unknown, making it impossible to accurately confirm whether there is sufficient oil supply to the piston 22, etc. Therefore, in the above embodiment, the engine load of the internal combustion engine 10 is limited in step S150. By limiting the engine load of the internal combustion engine 10 in this way, it is possible to prevent a situation in which the engine load of the internal combustion engine 10 is too high and there is insufficient oil supply.

[0023] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0024] The determination process (see Figure 2) for determining whether the OCV 62 is stuck closed may be performed in an operating state where the hydraulic pressure of the main gallery 51 is stable. The stability of the hydraulic pressure of the main gallery 51 can be determined, for example, by the fact that the fluctuation value of the hydraulic pressure of the main gallery 51 remains below a certain value for a certain period of time. Note that the hydraulic pressure of the main gallery 51 fluctuates according to the operating status of other hydraulic drive components such as the sub-gallery 61. Therefore, under conditions where the operating state of the internal combustion engine 10 is steady and there are no fluctuations in the operating status of other hydraulic drive components, if the only thing that changes is the opening and closing of the OCV 62, the possibility of hydraulic pressure fluctuations due to other factors can be eliminated.

[0025] As shown in Figure 3, if it is determined in step S140 that the OCV62 is stuck closed, the processes in steps S100-S120, S140, and S145 may be repeated a predetermined number of times (N times in Figure 3). If the determination in step S145 is "YES" after the predetermined number of times, the process may proceed to step S150. For example, if the opening of the OCV62 is obstructed due to foreign matter being caught, the OCV62 may return to normal by repeating the processes in steps S100-S120, S140, and S145 multiple times. In this case, the determination in step S120 will be "YES", and in step S130 it will be determined that the OCV62 is normal, thus avoiding the frequent display of the driver's notification (wrench mark).

[0026] In the above embodiment, a determination process (see Figure 2) was performed to determine whether or not the OCV62 was stuck in the closed position. However, in the determination process, a process may be performed to determine whether or not the OCV62 is stuck in the open position, in addition to determining whether or not the OCV62 is stuck in the closed position. When the OCV62 is stuck in the closed position, the hydraulic pressure in the main gallery 51 will not decrease, and when the OCV62 is stuck in the open position, the hydraulic pressure in the main gallery 51 will not increase. Therefore, by changing the threshold values ​​used in the determination in step S120 of Figure 2 to both the threshold value for the change in the hydraulic pressure decrease and the threshold value for the change in the hydraulic pressure increase, it becomes possible to detect not only the OCV62 stuck in the closed position but also the OCV62 stuck in the open position, which was not detected in the above embodiment. In this case, the problem of increased oil consumption due to continued stuck in the open position can be avoided.

[0027] The internal combustion engine 10 is not limited to a gasoline engine. The internal combustion engine 10 may be, for example, a diesel engine or a hydrogen engine. [Explanation of Symbols]

[0028] 10...Internal combustion engine, 22...Piston, 40...Oil supply mechanism, 41...Oil pump, 51...Main gallery, 52...Hydraulic sensor, 61...Sub gallery, 63...Oil jet, 70...Control device, 62...Oil control valve (OCV) as an on / off valve.

Claims

[Claim 1] The main gallery through which the oil pumped by the oil pump flows, Subgalleries branching off from the aforementioned main gallery, Connected to the aforementioned sub-gallery is an oil jet capable of injecting oil into the piston of an internal combustion engine, A hydraulic sensor for detecting the hydraulic pressure within the main gallery, A switching valve that can switch the aforementioned sub-gallery between an open state and a closed state, Applicable to an oil supply mechanism equipped with, An injection process which involves switching the on / off valve to an open state when the operating state of the internal combustion engine is in a predetermined specific operating state, thereby injecting oil from the oil jet; A determination process is performed to determine whether the on-off valve is stuck or not, based on fluctuations in hydraulic pressure detected by the hydraulic pressure sensor before and after the on-off valve is switched to the open state when the operating state of the internal combustion engine is not the specific operating state, It is possible to execute Control device for the oil supply mechanism.

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