JP2016169624A - Oil storage device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent failure of an engine, such as lubrication failure, from being caused by a frozen moisture mixed in an oil O.SOLUTION: An oil storage device of an engine includes: an oil pan 2 provided at a lower part of an engine body part 1; a reserve tank 4 provided in the oil pan 2; a thermo valve 43 which allows communication between interior parts of the oil pan 2 and the reserve tank 4 at a preset temperature or higher; a first strainer body 33 disposed in the oil pan 2; a second strainer body 34 disposed in the reserve tank 4; and an oil passage switch valve 37 provided in a portion where first and second branch pipes 31, 32 are joined. When an amount of a moisture mixed in an oil O is a predetermined amount or more and an oil temperature is lower than a predetermined temperature at the start-up of an engine, the oil passage switch valve 37 is switched so that the oil O is sucked through the second strainer body 34.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an oil storage device that stores engine oil, and more particularly, to an oil storage device in which an independent oil storage chamber such as a reserve tank is provided inside an oil pan.

  2. Description of the Related Art Conventionally, an oil storage device for an engine has been known in which an independent oil storage chamber is provided inside an oil pan in order to quickly raise the oil temperature when the engine is cold started. For example, the oil pan described in Patent Document 1 is partitioned by a partition member into a first chamber in which an oil strainer is disposed and a second chamber (independent oil storage chamber) other than that. . And the valve opened and closed by a bimetal is provided in the communicating hole which penetrates the partition member.

JP2013-136976A

  By the way, the combustion gas of the engine generally contains water vapor. For example, when the temperature of the engine is low such as in an unwarmed state, condensed water is generated in the crankcase, and the oil stored in the oil pan is stored in the oil pan. Will be mixed. In this regard, when the engine is frequently started and stopped like a hybrid vehicle, the engine operation is often stopped during warm-up, and moisture mixed in the oil accumulates without evaporating. It becomes like this.

  The water mixed in the oil in this way may freeze in an environment where the temperature is below freezing, such as in a cold region, and the ice blocks generated thereby may cause clogging of the mesh of the oil strainer. If this happens, the circulation of oil in the lubrication system of the engine is hindered, resulting in poor lubrication and the risk of malfunction of the hydraulic device receiving the oil supply.

  In view of such problems, an object of the present invention is to prevent problems such as poor lubrication from occurring due to freezing of water mixed in oil as described above.

  In order to achieve the above object, the present invention is directed to an oil storage device for storing engine oil, an oil pan provided at a lower portion of the engine body, a reserve tank provided inside the oil pan, and the oil While connecting the inside of the pan and the inside of the reserve tank at a preset temperature (hereinafter referred to as the set temperature) or higher, the thermo valve that shuts off below the set temperature and the oil stored in the oil pan are sucked in. A first oil strainer that is disposed in this manner, and a second oil strainer that is disposed so as to suck in oil stored in the reserve tank.

  An oil path switching valve that switches which oil path is used to suck oil is provided in a portion where the oil paths of the first and second oil strainers merge and is stored in the oil pan. The amount of water mixed in the oil is estimated, and when the estimated amount of water is equal to or greater than a predetermined amount and the temperature of the oil is lower than the predetermined temperature when the engine is started, the oil in the second oil strainer The oil path switching valve is switched so that oil is sucked in by the path.

  The set temperature for the thermo valve is a temperature at which water contained in the oil is almost evaporated, and may be set to about 100 ° C., for example. Further, the predetermined temperature that is determined when the engine is started is a temperature at which moisture is considered to be frozen in the oil, for example, zero degrees, and the predetermined amount of moisture is when the moisture is frozen. The amount of ice that is generated clogs the mesh of the oil strainer. Further, the amount of water mixed in the oil can be estimated based on a history such as the fuel injection amount until the oil temperature reaches the set temperature when the engine is cold-started.

  When the amount of water (estimated value) mixed in the oil is greater than or equal to a predetermined amount and the temperature of the oil is lower than the predetermined temperature when the engine is started, the second oil strainer The oil passage switching valve is switched to suck in the oil in the reserve tank. The oil in the reserve tank flows from the oil pan into the reserve tank via the thermo valve when the oil temperature is sufficiently high, and hardly contains moisture.

  Therefore, even in an environment where the temperature is below freezing, such as in a cold region, oil containing almost no ice blocks is sucked into the oil pump via the second oil strainer, and the mesh of the second oil strainer There is no worry of clogging. And since the oil discharged from the oil pump is supplied to the lubrication system of an engine, generation | occurrence | production of malfunctions, such as poor lubrication, can be prevented.

  Thereafter, as the engine warms up gradually, the temperature of the oil stored in the oil pan also rises, so that even if ice blocks are generated in the oil pan, it melts. Therefore, if the temperature of the oil rises to a certain level or higher (for example, if the temperature exceeds the predetermined temperature), the oil path switching valve may be switched so that the oil in the oil pan is sucked by the first oil strainer. .

  Further, when the temperature of the oil further rises to the above set temperature or more, the water contained in the oil will be almost evaporated, so the oil stored in the oil pan contains almost no water. Disappear. Thus, the oil containing no water flows into the reserve tank communicating from the oil pan through the thermo valve opened at the set temperature or higher, and is stored for the next engine start.

  As described above, according to the oil storage device of the present invention, when oil that does not contain water is stored in the reserve tank and the remaining water in the oil is frozen in the oil pan when the engine is started, When considered, since oil is sucked from the reserve tank, clogging of the mesh of the oil strainer, which is a concern in cold regions, can be effectively suppressed, and problems such as poor lubrication of the engine can be prevented.

It is a schematic block diagram of the oil storage apparatus which concerns on embodiment of this invention. It is a flowchart figure which shows the procedure of the switching of the oil path at the time of engine starting. FIG. 2 is a view corresponding to FIG. 1 when oil is sucked from a reserve tank. FIG. 2 is a view corresponding to FIG. 1 when oil is sucked from the oil pan. FIG. 2 is a view corresponding to FIG. 1 illustrating a state in which oil flows into the reserve tank from the oil pan.

  Hereinafter, an embodiment in which the present invention is applied to an engine mounted on a hybrid vehicle will be described as an example. As schematically shown in FIG. 1, an oil pan 2 is provided at the lower part of the main body 1 (cylinder block, cylinder head, etc.) of the engine according to the present embodiment. The engine oil O (hereinafter simply referred to as oil O) is stored.

  This oil O is pumped up through an oil strainer 3 by an oil pump 10 that is mechanically driven in accordance with the operation of the engine, discharged from the discharge port of the oil pump 10, and after passing through an oil filter (not shown). Distributes to the engine oil gallery. Then, after being supplied to each lubricating part of the engine, such as a crank journal, a cylinder bore, a valve train, etc., the oil O falls into the lower oil pan 2 and is stored again.

  In the present embodiment, a reserve tank 4 is provided inside the oil pan 2 as shown in FIG. As an example, the reserve tank 4 has a side wall portion 40 and a bottom portion 41 provided integrally with the side wall portion 20 of the oil pan 2 and is formed in a rectangular box shape opening upward, and the upper opening portion is a lid member. It is closed by 42 and is independent of the oil O storage space in the oil pan 2.

  Further, a thermo valve 43 is disposed through the bottom 41 of the reserve tank 4. The thermo valve 43 is of a thermo wax type, for example, and is closed when the temperature of the oil O in the oil pan 2 is lower than a preset temperature (for example, 100 ° C.), and is opened when the temperature is equal to or higher than the preset temperature. . That is, the thermo valve 43 allows the inside of the oil pan 2 and the inside of the reserve tank 4 to communicate with each other at the set temperature or higher, and shuts off below the set temperature.

  The set temperature is set as a temperature at which the water contained in the oil O is almost evaporated, so that the temperature of the oil O in the oil pan 2 reaches the set temperature and the thermo valve 43 is turned on. When opened, the oil O containing almost no water flows into the reserve tank 4 and is stored as will be described later.

  A level sensor 12 is disposed inside the reserve tank 4 in order to detect the oil level (oil level) of the oil O stored in this way. In addition, a well-known oil temperature sensor 13 is disposed at the bottom 21 of the oil pan 2 in order to detect the temperature (oil temperature) of the stored oil O. Signals output from the level sensor 12, the oil temperature sensor 13, and the like are input to an ECU 5 (Electronic Control Unit) that controls the engine.

  In the present embodiment, the oil strainer 3 sucks the first strainer body 33 arranged to suck the oil O stored in the oil pan 2 and the oil O stored in the reserve tank 4. And a second strainer main body 34 arranged as described above. That is, in the oil strainer 3, the upper end portion (one end portion) of the suction pipe 30 is connected to the oil pump 10, and the lower half portion of the suction pipe 30 branches into two, and the first and second branch pipes 31. , 32.

  Although schematically shown in FIG. 1, the first branch pipe 31 linearly extends downward from the lower end portion of the suction pipe 30, and a first strainer main body 33 provided at the lower end portion is provided. Soaked in oil O in oil pan 2. A mesh 35 for removing foreign matters when oil O is sucked is attached in the vicinity of the suction port 33a having a circular cross section that opens below the first strainer body 33.

  On the other hand, in the example shown in FIG. 1, the second branch pipe 32 extends substantially horizontally from the vicinity of the lower end portion of the suction pipe 30, that is, the vicinity of the branch portion with the first branch pipe 31, and then curves downward. Thus, the lid member 42 of the reserve tank 4 is vertically penetrated. A second strainer body 34 having the same configuration as the first strainer body 33 described above is provided at the lower end of the second branch pipe 32, and a mesh 36 is attached in the vicinity of the suction port 34a. It has been.

  Further, the branch pipes 31 and 32 are switched to suck the oil O into the portion where the oil passages of the first and second branch pipes 31 and 32 merge, that is, the lower end portion of the suction pipe 30. In addition, an oil passage switching valve 37 is provided. The oil path switching valve 37 is composed of, for example, an electromagnetic valve, and receives a signal (operation command) input from the ECU 5 so that an electromagnetic actuator operates the valve body.

  That is, the oil passage switching valve 37 communicates the oil passage in the suction pipe 30 and the oil passage in the first branch pipe 31 so that the oil O in the oil pan 2 is communicated as schematically shown in FIG. As shown schematically in FIG. 3, the oil passage in the suction pipe 30 and the oil passage in the second branch pipe 32 are communicated with each other so that the oil O in the reserve tank 4 is discharged. It can be switched to the second position for sucking.

  The ECU 5 includes a known electronic control unit, and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, and the like (not shown). The ECU 5 receives signals from various sensors in order to control the operation of the engine, and in the present embodiment, the level sensor 12, the oil temperature sensor 13, and the vehicle ignition switch 14 (hereinafter referred to as the following) IG-SW14).

  The ECU 5 executes a predetermined control program based on signals input from the sensors, switches, and the like, thereby switching the oil O suction destination when the engine is cold started. Specifically, as will be described below, the ECU 5 integrates the amount of moisture mixed into the oil O during operation of the engine, the moisture amount is equal to or greater than a predetermined amount, and the oil temperature is less than the predetermined temperature. At the time of cold start, the oil passage switching valve 37 is switched to the second position so that the oil O is sucked from the reserve tank 4 by the second strainer body 34.

  The reason why the oil O in the reserve tank 4 is sucked when a predetermined condition is satisfied at the time of cold start is to prevent problems such as poor lubrication of the engine. That is, first, since the combustion gas of the engine generally contains water vapor, when the temperature of the engine is low, for example, when the engine is not warmed up, the condensed water generated in the crankcase is transferred to the oil pan 2. It becomes mixed in the stored oil O.

  Particularly, in the engine of a hybrid vehicle such as this embodiment, since the start and stop frequently occur, the operation of the engine is often stopped in the middle of warm-up, and the water mixed in the oil O does not evaporate. Will be accumulated. The water thus mixed in the oil O may freeze in, for example, a cold district, and the ice lump I (see FIG. 3) generated thereby may cause the oil strainer 3 (first strainer body 33) when the engine is cold started. ) May cause clogging.

  Therefore, in the present embodiment, as will be described in detail below, during operation of the engine, oil O containing almost no moisture is stored in the reserve tank 4 in advance, and the oil pan 2 is stored in the engine when the engine is cold started. If it is determined that the water remaining in the oil O is frozen and an ice block I of a predetermined amount or more is generated, the second strainer main body 34 sucks the oil O containing no ice block I from the reserve tank 4. It is what.

  3 to 5, the procedure for controlling the oil passage switching valve 37 performed by the ECU 5 at the time of cold start of the engine, that is, the procedure for switching the oil passage in the oil strainer 3 will be described in detail with reference to the flowchart of FIG. 2. I will explain it.

-Oil path switching during cold engine start-
First, for example, when the engine is started by turning on the IG-SW 14, for example, the flow of FIG. 2 starts in response to the input of a signal from the IG-SW 14, and in step ST1, moisture mixed in the oil O It is determined whether the amount (estimated value) is equal to or greater than a predetermined amount. The estimated value of the moisture amount is an integrated value of the condensed water mixed in the oil O during the previous operation of the engine, and a detailed description thereof is omitted, but can be obtained as follows, for example.

  That is, in view of the fact that the water vapor contained in the combustion gas is condensed in the crankcase and mixed into the oil O when the engine is not warmed up, first, the engine operating conditions (load factor, rotational speed) The amount of condensed water generated for each combustion cycle, for example, according to the fuel injection amount, outside air temperature, oil temperature, water temperature, etc., is determined in advance through experiments or the like to create a map and electronically store it in the ROM of the ECU 5 deep. Then, after cold start, the values read from the map are integrated for each combustion cycle of the engine, and when the oil temperature reaches, for example, 100 ° C., the integrated value is reset to zero.

  In step ST2 following step ST1, the current temperature (oil temperature) of the oil O is calculated and compared with a predetermined temperature. This may be detected, for example, by a signal from the oil temperature sensor 13, or in addition to that, the oil temperature is estimated based on a signal from a water temperature sensor (not shown) and the engine load factor, rotation speed, etc. be able to. Further, the predetermined temperature is a temperature at which water contained in the oil O is frozen, and may be set to 0 ° C., for example.

  If the oil temperature is equal to or higher than the predetermined temperature and a negative determination is made in step ST2 (NO), the process proceeds to step ST5 described later, and the oil path switching valve 37 is maintained at the first position, while the oil temperature is the predetermined temperature. If the determination in step ST2 is affirmative (YES), the process proceeds to step ST3 to switch the oil passage switching valve 37 to the second position. Thereby, as schematically shown in FIG. 3, the oil passage in the suction pipe 30 and the oil passage in the second branch pipe 32 communicate with each other.

  When the starter motor starts operating in this state and the crankshaft of the engine rotates and the oil pump 10 is driven, as shown by the arrow in FIG. 3, the ice block from the reserve tank 4 by the second strainer body 34. Oil O which does not contain I comes to be sucked. Since this oil O is discharged from the oil pump 10 and supplied to each lubrication part of the engine and then returned to the oil pan 2, the oil temperature gradually rises as the engine warms up.

  Until the rising oil temperature reaches the predetermined temperature, a negative determination (NO) is made in step ST4, a negative determination (NO) is made in step ST6, the flow returns to step ST3, and the oil passage switching valve 37 is returned. Is maintained in the second position. On the other hand, if the oil temperature is equal to or higher than the predetermined temperature, an affirmative determination is made in step ST4 (YES), the process proceeds to step ST5, the oil path switching valve 37 is switched to the first position, and the control is terminated (end).

  As a result, the oil passage in the suction pipe 30 and the oil passage in the first branch pipe 31 are communicated with each other as schematically shown in FIG. 4, and the first strainer body 33 is shown with an arrow in FIG. As a result, the oil O in the oil pan 2 is sucked. At this time, it is considered that the ice block I contained in the oil O at a predetermined temperature or higher is almost melted, so there is no concern that the mesh 35 of the first strainer body 33 is clogged. In step ST4, the temperature may be compared with a slightly higher temperature than the predetermined temperature (for example, 0 ° C.).

  As a result, the oil O in the oil pan 2 is sucked into the oil pump 10 and supplied to each lubricating part of the engine, and the oil temperature rises to the above set temperature (for example, 100 ° C.) or more. If it becomes, the water | moisture content contained in the oil O will evaporate. Thus, the oil O containing almost no water flows into the reserve tank 4 through the thermo valve 43 opened at the set temperature as shown by an arrow in FIG. 5 and is stored for the next engine start. Become.

  In addition, it is conceivable that the oil O in the reserve tank 4 disappears before the oil temperature reaches the set temperature as described above. However, in this case, the step after the negative determination (NO) in the step ST4 In ST6, an affirmative determination is made that the reserve tank 4 has been emptied based on the signal from the level sensor 12 (YES), the process proceeds to the above-mentioned step ST5, the oil passage switching valve 37 is switched to the first position, and the control ends. (End).

  As described above, according to the oil storage device for an engine according to the present embodiment, the reserve tank 4 is provided inside the oil pan 2 provided at the lower part of the main body 1 of the engine, and the oil containing no moisture is supplied. The oil O is sucked from the reserve tank 4 when it is considered that an ice block I of a predetermined amount or more is present in the oil pan 2 when the engine is cold started. Thereby, clogging of the meshes 35 and 36 of the oil strainer 3 which is a concern in cold regions can be effectively suppressed, and problems such as poor lubrication of the engine can be prevented.

-Other embodiments-
The above-described embodiments are merely examples, and are not intended to limit the configuration and use of the present invention. For example, in the above-described embodiment, the first branch pipe 31 of the oil strainer 3 is disposed so as to extend in the vertical direction. However, the first branch pipe 31 is not limited to this. The first and second branch pipes 31 and 32 may be formed in a curved shape or a bent shape.

  Moreover, although the said embodiment demonstrated the example which applied this invention to the engine mounted in a hybrid vehicle, it is not limited to this, This invention is applied also to the engine mounted in vehicles other than a hybrid vehicle. Applicable.

  INDUSTRIAL APPLICABILITY The present invention can prevent problems such as poor lubrication that can occur in cold regions in an engine, and is particularly effective when applied to an engine for a hybrid vehicle.

1 Engine body (engine body)
2 Oil pan 3 Oil strainer 30 Suction pipe 31 First branch pipe (oil passage of the first oil strainer)
32 Second branch pipe (oil passage of second oil strainer)
33 First strainer body (first oil strainer)
34 Second strainer body (second oil strainer)
37 Oil path switching valve 4 Reserve tank 43 Thermo valve 5 ECU
O Engine oil (oil)

Claims (1)

An oil storage device for storing engine oil,
An oil pan provided at the bottom of the engine body,
A reserve tank provided inside the oil pan;
A thermo valve that connects the inside of the oil pan and the inside of the reserve tank at a temperature higher than a preset temperature, and shuts off below the temperature;
A first oil strainer arranged to suck in oil stored in the oil pan;
A second oil strainer arranged to suck in oil stored in the reserve tank;
An oil passage switching valve that is provided at a portion where the oil passages of the first and second oil strainers merge, and that switches which oil passage is sucked in;
When the amount of water mixed in the oil stored in the oil pan is estimated, and the estimated amount of water is not less than a predetermined amount and the temperature of the oil is lower than the predetermined temperature when the engine is started, An oil storage device for an engine, wherein the oil passage switching valve is switched so that oil is sucked in by an oil passage of the second oil strainer.

Images