JP5370307B2 - Hydraulic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent detection of failure of oil level in an oil storage, caused by increase of an oil relief amount of a relief valve. <P>SOLUTION: The device includes: an oil pressure setter for setting an oil pressure in an oil path on a discharge side of an oil pump to a first oil pressure or a second oil pressure which is lower than the first oil pressure, by controlling the oil relief amount of the relief valve; and an oil level detector for detecting the oil level when the oil level in the oil storage exceeds a predetermined value. A detection inhibitor inhibit the detection by the oil level detector when the oil pressure setter sets the oil pressure in the oil path on the discharge side of the oil pump to the second oil pressure (ST2:NO). <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an engine hydraulic control device.

  Conventionally, a device for controlling the oil pressure of the oil in the engine circulated by the oil pump has been proposed. In such a device, the hydraulic pressure in the oil passage is controlled by opening and closing a relief valve provided in the oil passage using an electromagnetic valve. For example, when the relief valve is relieved at a low oil pressure or is relieved at a high oil pressure (normal oil pressure), the oil pressure is set to either a low oil pressure or a high oil pressure. Such a system is sometimes referred to as a two-stage hydraulic system. In such a two-stage hydraulic system, it is possible to reduce the load on the oil pump by setting the hydraulic pressure to a low hydraulic pressure, or to stop the oil injection from the piston oil jet when cold. Thereby, the effect of the fuel consumption improvement by the fall of the load of the engine which drives an oil pump, or early warm-up completion can be acquired. This type of hydraulic control device (two-stage hydraulic system) is disclosed in Patent Document 1, for example.

JP 2009-97390 A

  By the way, in the hydraulic control apparatus as described above, since the relief amount of the relief valve increases at low oil pressure, the oil level in the oil reservoir (oil pan) rises, and the actual total oil amount in the engine is reduced. An oil level abnormality may be detected even though it has not increased. When an abnormality in the oil level is detected, there is a problem such as a warning lamp that turns it on.

  The present invention was devised in view of such problems, and is a hydraulic control that prevents the detection of an abnormality in the oil level in the oil reservoir due to an increase in the oil relief amount of the relief valve. An object is to provide an apparatus.

  As means for solving the above-described problems, the hydraulic control device of the present invention is configured as follows.

  That is, the hydraulic control device according to the present invention has a hydraulic pressure setting means for setting the hydraulic pressure in the oil passage on the discharge side of the oil pump by controlling the oil relief amount by the relief valve, and the oil level in the oil reservoir is predetermined. And an oil level detecting means for detecting when the value exceeds the value, and the oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump to a predetermined value or less. And a detection prohibiting means for prohibiting the detection by the oil level detecting means.

  In the hydraulic control device, the hydraulic pressure setting means sets the hydraulic pressure in the oil passage on the discharge side of the oil pump by controlling the oil relief amount by the relief valve, and the detection prohibition Means for prohibiting the detection by the oil level detecting means when the oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump to a predetermined level or less excluding the highest level. It may be.

  In the hydraulic control device, the hydraulic pressure setting means controls the oil relief amount by the relief valve so that the hydraulic pressure in the oil passage on the discharge side of the oil pump is the first hydraulic pressure or a lower pressure than the first hydraulic pressure. Even if the detection prohibiting unit prohibits the detection by the oil level detecting unit when the hydraulic control unit sets the hydraulic pressure to the second hydraulic pressure. Good.

  According to the hydraulic control device having the above-described configuration, the oil level in the oil reservoir is not increased because the total oil amount in the engine has not increased due to an increase in the oil relief amount of the relief valve. Detecting a level abnormality is suppressed.

  According to the hydraulic control device of the present invention, it is possible to suppress an abnormality in the oil level in the oil reservoir due to an increase in the oil relief amount of the relief valve.

It is a figure which shows schematic structure of a diesel engine. It is a block diagram which shows the input / output of ECU. It is the figure which showed schematic structure of the hydraulic control circuit. It is the figure which showed schematic structure of the hydraulic control circuit. It is a flowchart which shows the specific example of the procedure of hydraulic control. It is a flowchart which shows the operation example of ECU etc. after an engine start. It is a flowchart which shows the operation example of ECU etc. at the time of DPF regeneration control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

-Engine-
A schematic configuration of a diesel engine whose hydraulic pressure is controlled by a hydraulic control apparatus according to an embodiment of the present invention will be described with reference to FIG.

  A diesel engine 1 (hereinafter referred to as “engine 1”) in the present embodiment is, for example, a common rail in-cylinder direct injection four-cylinder engine, and the combustion chamber 1a of each cylinder of the engine 1 includes the combustion chamber 1a. Injectors (fuel injection valves) 2 for injecting fuel to be used for combustion are disposed. The injector 2 for each cylinder is connected to a common rail 11. A supply pump 10 is connected to the common rail 11.

  The supply pump 10 pumps fuel from the fuel tank, and makes the pumped fuel high pressure and supplies it to the common rail 11 through the fuel passage 10a. The common rail 11 distributes the fuel to the injectors 2 while holding (accumulating) the high-pressure fuel supplied from the supply pump 10 at a predetermined pressure. The injector 2 is an electromagnetically driven on / off valve that injects and supplies fuel into the combustion chamber 1a. The opening / closing (fuel injection amount / injection timing) of the injector 2 is controlled by an ECU (Electronic Control Unit) 100.

  An intake passage 3 and an exhaust passage 4 are connected to the engine 1. In the intake passage 3, an air cleaner 9, an air flow meter 33, a compressor impeller 63 of a turbocharger 6 to be described later, an intercooler 8, and a throttle valve 5 are arranged in order from the upstream side to the downstream side. The throttle valve 5 is adjusted in throttle opening by a throttle motor 51. The throttle opening of the throttle valve 5 is detected by a throttle opening sensor 41. The intake passage 3 is branched corresponding to each cylinder at an intake manifold 3 a disposed on the downstream side of the throttle valve 5.

  The exhaust passage 4 is configured to gather into one from a state branched for each cylinder by an exhaust manifold 4a connected to the combustion chamber 1a of each cylinder of the engine 1.

  The exhaust passage 4 includes a CCO (oxidation catalytic converter) 21 that oxidizes and purifies HC (hydrocarbon) and CO (carbon monoxide) contained in the exhaust gas, and a DPF 22 that collects PM (particulate matter). Are arranged in order, and the exhaust gas generated by the combustion in the combustion chamber 1a is sent in.

  An A / F sensor 36 and a first exhaust temperature sensor 37 are arranged in the exhaust passage 4 upstream of the CCO 21, and the temperature of the exhaust gas entering the CCO 21 can be detected from the output signal of the first exhaust temperature sensor 37. it can. A second exhaust temperature sensor 38 is disposed between the CCO 21 and the DPF 22, and the temperature of the exhaust gas entering the DPF 22 can be detected from the output signal of the second exhaust temperature sensor 38. Further, a differential pressure sensor 39 that detects a differential pressure between the upstream pressure and the downstream pressure of the DPF 22 is provided.

  Output signals of the A / F sensor 36, the first exhaust temperature sensor 37, the second exhaust temperature sensor 38, and the differential pressure sensor 39 are input to the ECU 100.

  The engine 1 is equipped with a turbocharger 6. The turbocharger 6 includes a turbine wheel 62 and a compressor impeller 63 that are connected via a rotor shaft 61.

  The compressor impeller 63 is arranged facing the inside of the intake passage 3, and the turbine wheel 62 is arranged facing the inside of the exhaust passage 4. Such a turbocharger 6 supercharges intake air by rotating the compressor impeller 63 using the exhaust flow (exhaust pressure) received by the turbine wheel 62. The intake air whose temperature has been raised by supercharging in the turbocharger 6 is forcibly cooled by an intercooler 8 disposed in the intake passage 3.

  Further, the engine 1 is equipped with an EGR device 7. The EGR device 7 recirculates a part of the exhaust gas flowing in the exhaust passage 4 to the intake passage 3 and supplies it again to the combustion chamber 1a of each cylinder to lower the combustion temperature, thereby reducing the amount of NOx generated. . The EGR device 7 includes an EGR passage 71 that connects the intake manifold 3a and the exhaust manifold 4a. The EGR passage 71 is provided with an EGR cooler 73 and an EGR valve 72 for cooling the EGR gas passing through (refluxing) the EGR passage 71 in order from the upstream side of the EGR gas flow. By adjusting the opening, the amount of EGR gas (exhaust gas recirculation amount) introduced from the exhaust passage 4 (exhaust manifold 4a) to the intake passage 3 (intake manifold 3a) is adjusted.

-ECU-
As shown in FIG. 2, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  The CPU 101, ROM 102, RAM 103, and backup RAM 104 are connected to each other via a bus 107, and are connected to an input interface 105 and an output interface 106.

  The input interface 105 is disposed in an engine speed sensor 31 that detects the speed of a crankshaft that is the output shaft of the engine 1, a water temperature sensor 32 that detects an engine water temperature (cooling water temperature), an air flow meter 33, and an intake manifold 3a. An intake air temperature sensor 34 for detecting the temperature of intake air, an intake air pressure sensor 35 for detecting the pressure of intake air, an A / F sensor 36, a first exhaust gas temperature sensor 37, and a second exhaust gas temperature sensor. 38, a differential pressure sensor 39, a rail pressure sensor 40 that detects the pressure of high-pressure fuel in the common rail 11, a throttle opening sensor 41, an accelerator opening sensor 42, a hydraulic sensor 43 that detects the hydraulic pressure of the engine 1, and an oil pan An oil level sensor 44 or the like for detecting the oil level is connected, and from these sensors, Signal is input to the ECU 100.

  Connected to the output interface 106 are an injector 2, a supply pump 10, a throttle motor 51 of the throttle valve 5, an EGR valve 72, a warning lamp 81 for informing the driver of an abnormality in the oil level of the engine 1, and the like. Yes.

  The ECU 100 executes various controls of the engine 1 including opening control of the throttle valve 5 of the engine 1 and fuel injection amount / injection timing control (opening / closing control of the injector 2) based on the output signals of the various sensors described above. . Further, the ECU 100 executes DPF regeneration control described later.

-DPF regeneration control-
First, the ECU 100 estimates the accumulation amount of PM collected in the DPF 22 based on the output signal of the differential pressure sensor 39 provided in the DPF 22, and the estimated PM amount is equal to or greater than the regeneration start determination value (allowable limit value). When it becomes, it is determined that it is time to regenerate the DPF 22, and post injection is performed after main fuel injection to the engine 1, and PM accumulated in the DPF 22 is burned and removed to regenerate the DPF 22.

  For example, after performing main fuel injection (main injection), which is fuel injection for engine operation (fuel injection from the injector 2 to the combustion chamber 1a), CCO temperature rising fuel injection (first post injection) is executed. The fuel injected from the injector 2 by this CCO temperature rising fuel injection is sent to the exhaust passage 4 and reaches the CCO 21. When the fuel component reaches the CCO 21, components such as HC and CO are oxidized in the exhaust gas or on the catalyst, and the temperature of the CCO 21 (exhaust gas) rises due to the heat generated by the oxidation reaction. The temperature rises. Then, after performing such CCO temperature rising fuel injection, PM accumulated in the DPF 22 is burned and removed by performing DPF regeneration fuel injection (second post injection) at a predetermined timing (for example, exhaust stroke). The

  By executing such DPF regeneration control, the amount of accumulated PM in the DPF 22 decreases, and the DPF regeneration control ends when the amount of decrease in PM becomes smaller than the regeneration completion determination value. The amount of decrease in PM is, for example, the engine speed Ne obtained from the output signal of the engine speed sensor 31, the exhaust temperature obtained from the output signal of the second exhaust temperature sensor 38 (the temperature of the exhaust gas entering the DPF 22), etc. And can be estimated with reference to a map or the like.

-Hydraulic control circuit-
Next, a hydraulic control circuit 200 for controlling the hydraulic pressure of oil (lubricating oil) in the engine 1 will be described. 3 and 4 are diagrams showing a schematic configuration of the hydraulic control circuit 200. FIG. The hydraulic control circuit 200 includes a relief valve 210 in which the oil relief pressure is variable, and a control valve 220 (hereinafter also referred to as “OSV 220”) that controls the relief pressure of the relief valve. The OSV 220 controls the relief pressure of the relief valve 210 to a high hydraulic pressure (normal hydraulic pressure; first hydraulic pressure) or a low hydraulic pressure (second hydraulic pressure) in accordance with a command from the ECU 100 (hereinafter, the relief pressure is set to “high hydraulic pressure”). The control that controls “high pressure control” and “low hydraulic pressure” is also called “low pressure control”.) FIG. 3 shows a state when the relief valve 210 relieves oil at a low oil pressure, and FIG. 4 shows a state when the relief valve 210 relieves oil at a high oil pressure.

  An oil pump 233 is disposed in an oil passage (oil passage) 232 that supplies oil in the oil pan (oil storage portion) 231 to each part of the engine 1. The oil passage 232 branches to the first branch 234 on the discharge side of the oil pump 233, and further branches to the second branch 235 on the downstream side thereof. A relief valve 210 is incorporated in the first branch path 234. The relief valve 210 is connected to a relief path 236 for relieving the oil discharged from the oil pump 233 to the upstream side of the oil pump 233.

  The relief valve 210 includes a case 211, a sleeve 212, a valve body 213, a spring 214, a retainer 215, and the like.

  The case 211 accommodates the sleeve 212 so as to be slidable. The case 211 has one end communicating with the first branch path 234, the intermediate side surface communicating with the relief path 236, and the other end side surface communicating with the pilot path 237. The case 211 has two inner diameter parts, a small diameter part 211a and a large diameter part 211b. The relief path 236 communicates with the small diameter part 211a, and the pilot path 237 communicates with the large diameter part side. Yes.

  The sleeve 212 has an outer diameter corresponding to each of the small diameter portion 211a and the large diameter portion 211b of the case 211, and a relief hole 212a that communicates the inner and outer spaces is formed in an intermediate portion of the sleeve 212. A valve body 213 is slidably fitted on the inner peripheral surface of the sleeve 212. The sleeve 212 has an annular first pressure receiving surface S1 facing the first branch passage 234 and an annular second pressure receiving surface S2 formed on the side opposite to the sliding direction (pilot path 237 side) with respect to the first pressure receiving surface S1. The area of the second pressure receiving surface S2 is larger than the area of the first pressure receiving surface S1.

  The valve body 213 is urged toward the first branch path 234 by a compression coil spring 214 (hereinafter referred to as “spring 214”) interposed between the back portion and the retainer.

  The retainer 215 has a bottomed cylindrical portion 215a that supports the end of the spring 214, and the end on the large diameter side of the sleeve 212 is slidably fitted on the outer periphery of the bottomed cylindrical portion 215a.

  The OSV 220 is composed of, for example, a two-position solenoid valve, and communicates the pilot path 237 and the second branch path 235 in the excited state as shown in FIG. 3, while in the non-excited state as shown in FIG. And an oil discharge path 238 to the oil pan 231. Note that a check valve 239 is provided in the oil discharge path 238 to prevent backflow of oil from the oil pan 231.

  As shown in FIG. 3, when the OSV 220 is excited according to a command from the ECU 100 and oil is supplied from the second branch path 235 to the pilot path 237, the inner peripheral surface of the case 211 and the bottomed cylindrical portion 215 a of the retainer 215. The hydraulic pressure is supplied to the second hydraulic chamber R2 formed between the outer peripheral surface of the first hydraulic chamber R2. As a result, hydraulic pressure acts on both pressure receiving surfaces S1 and S2 of the sleeve 212, and the sleeve 212 and the relief hole 212a move to the first branch path 234 side (side on which the spring 214 extends) due to the pressure receiving area difference. As a result, the urging force of the spring 214 is relatively small, and the valve body 213 is opened to allow the first branch path 234 and the relief path 121 to communicate with each other even if the hydraulic pressure in the first branch path 234 is relatively low. Thereby, the hydraulic pressure in the oil passage 232 on the discharge side of the oil pump 233 is set to a low hydraulic pressure. The low oil pressure is set to a minimum oil pressure required when the engine 1 is in a light load operation state.

  As shown in FIG. 4, when the OSV 220 is de-energized by a command from the ECU 100 and the pilot path 237 is connected to the oil discharge path 238, the hydraulic pressure in the second hydraulic chamber R <b> 2 disappears, and both pressure receiving surfaces of the sleeve 212 are received. Of S1 and S2, the hydraulic pressure acts only on the first hydraulic pressure surface S1, and the sleeve 212 and the relief hole 212a move to the retainer 215 side (the side on which the spring 214 contracts). As a result, the urging force of the spring 214 becomes relatively large, and the hydraulic pressure in the first branch 234 necessary for opening the valve body 213 and communicating the first branch 234 and the relief path 121 becomes relatively high. Thereby, the hydraulic pressure in the oil passage 232 is set to a high hydraulic pressure.

  3 and 4, reference numeral 240 is a strainer, reference numeral 241 is an oil filter, and reference numeral 43 is a hydraulic pressure sensor for detecting the hydraulic pressure in the oil passage 232. Reference numeral 44a is an upper oil level sensor, and reference numeral 44b is a lower oil level sensor. The upper oil level sensor 44a is provided to detect the allowable upper limit position of the oil level in the oil pan 231. The lower oil level sensor 44b detects the allowable lower limit position of the oil level in the oil pan 231. Is provided to do.

  The ECU 100 executes low pressure control after the engine 1 is started and after a predetermined short time (for example, 10 seconds) has elapsed until the warm-up of the engine 1 is completed, except in a case where the low pressure control is prohibited as described later. Moreover, if the predetermined low pressure control execution condition is satisfied even after the warm-up of the engine 1 is completed, the low pressure control is executed. As the predetermined low-pressure control execution condition, for example, the load (for example, accelerator opening degree) of the engine 1 and the engine speed are not more than a predetermined value, and the coolant temperature of the engine 1 is within a predetermined range (for example, about 15 ° C. to about 95 ° C.).

  On the other hand, when the low pressure control prohibition state is set, the ECU 100 executes the high pressure control even if the low pressure control execution condition is satisfied. Here, the low-pressure control prohibited state includes a state during execution of DPF regeneration control and a state described based on a flowchart described later (see step ST5 in FIG. 5).

  The ECU 100 monitors whether the oil level in the oil pan 231 exceeds the allowable upper limit position or falls below the allowable lower limit position based on the outputs of the upper oil level sensor 44a and the lower oil level sensor 44b. ing. If the oil level exceeds the allowable upper limit position or falls below the allowable lower limit position, a warning lamp 81 is turned on to detect this and notify the driver of the oil level error.

  However, at the time of low pressure control, the relief amount of the relief valve 210 increases, so that a phenomenon occurs in which the oil level in the oil pan 231 rises even though the actual total oil amount in the engine has not increased. Therefore, ECU 100 does not detect an abnormality in the oil level based on the output of upper oil level sensor 44a during low pressure control.

-Specific examples of hydraulic control procedures-
Next, a specific example of the hydraulic control procedure of the ECU 100 will be described based on the flowchart of FIG. The processing operation of the ECU 100 described based on this flow is repeatedly executed every predetermined time. Further, the ECU 100 sets the pressure control flag to “1” during the low pressure control, and sets the pressure control flag to “0” during the high pressure control. Further, the DPF regeneration control flag is set to “1” during the DPF regeneration control, and the DPF regeneration control flag is set to “0” when not in the DPF regeneration control.

  In step ST1, it is determined whether or not there is a determination request for determining whether the oil level in the oil pan 231 has exceeded the allowable upper limit position (request for determining an abnormality in the oil level based on the output of the upper oil level sensor 42a). To do. Here, if an affirmative determination is made, the process proceeds to step ST2, and if a negative determination is made, the present routine is exited.

  In step ST2, it is determined with reference to the pressure control flag whether low pressure control is being performed. If the determination is affirmative, the routine is exited. If the determination is negative, the routine proceeds to step ST3.

  In step ST3, it is determined whether or not the oil level in the oil pan 231 has exceeded the allowable upper limit position based on the output of the upper oil level sensor 42a.

  In step ST4, it is determined whether the result of the determination based on the output of the upper oil level sensor 44a is normal (OK) or abnormal (NG). If the determination is normal, this routine is exited and the determination is abnormal. Moves to step ST5.

  In step ST5, a low pressure control prohibition flag is set in order to prohibit low pressure control and prevent further increase in the oil level in the oil pan 231. When this flag is set, the ECU 100 does not execute the low pressure control even if the low pressure control execution condition is satisfied.

  In step ST6, a warning lamp 81 is lit to notify the driver of an abnormality in the oil level in the oil pan 231.

  In step ST7, it is determined based on the state of the DPF regeneration control flag whether or not the DPF regeneration control is being performed. Here, if an affirmative determination is made, the process proceeds to step ST8, and if a negative determination is made, the present routine is exited.

  In step ST8, the DPF regeneration control is stopped. Thereby, the rise of the oil level by DPF regeneration control is stopped.

-Operation example after engine start-
Next, an example of the operation of the ECU 100 and the like after starting the engine will be described based on the flowchart of FIG.

  The ECU 100 executes high pressure control for a predetermined short time (for example, 10 seconds) at the same time as starting the engine 1 (step ST11). Immediately after the engine 1 is started, it is assumed that the oil does not reach every corner of the object to be lubricated in the engine 1. Therefore, by performing high pressure control for a predetermined short time immediately after the engine 1 is started, the oil is lubricated. Spread to every corner.

  After the predetermined short time, the high pressure control is switched to the low pressure control (step ST12). This low pressure control is continued until the engine warm-up is completed, for example, until the coolant temperature reaches a predetermined temperature (for example, 80 ° C.) or higher (step ST13: NO).

  After the engine warm-up is completed (step ST13: YES), regardless of whether or not the low-pressure control execution condition is satisfied, the high-pressure control is forcibly executed (step ST14), and an oil level abnormality determination request is made. Is performed (step ST15). That is, the routine described based on FIG. 5 is started, and it is determined whether or not the oil level in the oil pan 231 has exceeded the allowable upper limit position. After exiting the routine of FIG. 5, the forced high pressure control is released (step ST <b> 16), and low pressure control or high pressure control is executed according to the operating state of the engine 1.

-Operation example during DPF regeneration control-
Next, an operation example of the ECU 100 and the like during DPF regeneration control will be briefly described based on the flowchart of FIG.

  At the time of DPF regeneration control, the oil level by the post-injected fuel (fuel mixture into the engine oil) increases, so it is necessary to monitor the oil level. For this reason, when there is a DPF regeneration request, the ECU 100 forcibly executes the high pressure control (step ST21), executes the DPF regeneration control, and periodically determines an abnormality in the oil level during the DPF regeneration control. A request is made (step ST22). That is, the routine described based on FIG. 5 is started periodically. When the routine of FIG. 5 is started (step ST1: YES), since the high pressure control is forcibly performed during the DPF regeneration control (step ST2: NO), it is determined whether or not the oil level has exceeded the allowable upper limit position. Determine (step ST3). If the determination result is an abnormality determination (NG), then the low pressure control is prohibited (step ST5), the warning lamp 81 is turned on (step ST6), and the DPF regeneration control is stopped (step ST7: YES, Step ST8). On the other hand, if the determination result is normal determination (OK), the DPF regeneration control is continued.

  When the decrease amount of PM becomes smaller than the regeneration completion determination value described above, when the DPF regeneration control is finished (step ST23), the forced high pressure control is canceled (step ST24), and depending on the operating state of the engine 1 Low pressure control or high pressure control is executed.

  After a predetermined time (for example, 60 to 120 minutes) elapses after the DPF regeneration control is completed (step ST25), forced high pressure control is executed again (step ST26), and an oil level abnormality determination request is made (step ST26). That is, by entering the routine described based on FIG. 5, it is determined whether or not the oil level in the oil pan 231 has exceeded the allowable upper limit position (step ST27). When entering the routine of FIG. 5 (step ST1: YES), since forced high pressure control is being performed (step ST2: NO), it is determined whether or not the oil level has exceeded the allowable upper limit position (step ST3). . If the determination result is an abnormality determination (NG), then the low pressure control is prohibited (step ST5), and the warning lamp 81 is turned on (step ST6, step ST7: NO). After exiting the routine of FIG. 5, the forced high pressure control is canceled (step ST28), and the low pressure control or the high pressure control is executed according to the operating state of the engine 1.

  The predetermined time of ST25 is a time required for the fuel evaporation in the oil diluted with the fuel to settle down. This time may be a fixed time, but since the fuel evaporation rate in the oil changes according to the coolant temperature, the relationship between the time required for the fuel evaporation in the oil to settle and the coolant temperature It is desirable that the ECU 100 sets the above time based on this map and the coolant temperature.

  When the ignition is turned off during DPF regeneration control (step ST29), ECU 100 returns the process to step ST21 and immediately executes forced high pressure control, DPF regeneration control, and the like.

  On the other hand, the ECU 100 issues a request for interrupting the DPF regeneration control during the DPF regeneration control when a sufficient exhaust temperature cannot be obtained, such as when the load of the engine 1 is below a predetermined level for a certain period of time (step S100). (ST31), DPF regeneration control is interrupted (step ST32), forced high pressure control is executed (step ST26), an oil level abnormality determination request is made (that is, the routine described based on FIG. 5 is entered). ), It is determined whether or not the oil level in the oil pan 231 has exceeded the allowable upper limit position (step ST27). When entering the routine of FIG. 5 (step ST1: YES), since forced high pressure control is being performed (step ST2: NO), it is determined whether or not the oil level has exceeded the allowable upper limit position (step ST3). . If the determination result is an abnormality determination (NG), then the low pressure control is prohibited (step ST5), and the warning lamp 81 is turned on (step ST6, step ST7: NO). After exiting the routine of FIG. 5, the forced high pressure control is canceled (step ST28), and the low pressure control or the high pressure control is executed according to the operating state of the engine 1. After exiting the routine of FIG. 5, the forced high pressure control is canceled (step ST28), and the low pressure control or the high pressure control is executed according to the operating state of the engine 1.

  According to the hydraulic control apparatus according to the embodiment of the present invention described above, the total oil amount in the engine 1 is not increased due to an increase in the oil relief amount of the relief valve 210. Regardless of this, it is possible to prevent the abnormality of the oil level in the oil pan 231 from being detected and the warning lamp 82 notifying the abnormality of the oil level to be lit.

-Other embodiments-
In the above-described embodiment, the two-stage hydraulic system that can set the oil pressure on the discharge side of the oil pump 233 in two stages by setting the oil relief amount by the relief valve 210 in two stages has been described as an example. Alternatively, a relief valve or the like that can set the relief amount at three or more stages (or steplessly) may be adopted so that the oil pressure on the discharge side of the oil pump 233 can be set at three or more steps (or steplessly). In this case, when the oil pressure on the discharge side of the oil pump is set to a predetermined level or less (or a predetermined hydraulic value or less) excluding the highest level, the oil level is not determined based on the output of the upper oil level sensor 44a. By doing so, the same effect as described above can be obtained.

  The present invention can be applied to, for example, a two-stage hydraulic system of an automobile engine.

44a Upper oil level sensor (oil level detection means)
100 ECU
210 Relief valve 231 Oil pan (oil reservoir)
232 Oil passage (oil passage on the oil pump discharge side)
233 oil pump

Claims (3)

Oil pressure setting means that sets the oil pressure in the oil passage on the discharge side of the oil pump by controlling the amount of oil relief by the relief valve, and detects when the oil level in the oil reservoir exceeds a predetermined value In a hydraulic control device comprising an oil level detection means,
When the oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump to a predetermined value or less, the oil pressure setting means comprises detection prohibiting means for prohibiting the detection by the oil level detecting means. Hydraulic control device to do. The hydraulic control device according to claim 1,
The oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump in multiple stages by controlling the amount of oil relief by the relief valve,
The detection prohibiting means performs the detection by the oil level detecting means when the oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump to a predetermined level or less excluding the highest level. A hydraulic control device characterized by being prohibited. In the hydraulic control device according to claim 2,
The oil pressure setting means sets the oil pressure in the oil passage on the discharge side of the oil pump to the first oil pressure or the second oil pressure lower than the first oil pressure by controlling the amount of oil relief by the relief valve. ,
The hydraulic pressure control apparatus according to claim 1, wherein the detection prohibiting means prohibits the detection by the oil level detecting means when the hydraulic pressure control means sets the hydraulic pressure to a second hydraulic pressure.

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