JP2008121621A - Device and method for estimating mixing, and engine oil recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate at least an index value indicating degree of the mixing of water into engine oil. <P>SOLUTION: A mixing estimation device is mounted to a vehicle and provided with an oil temperature detection means 21 detecting the temperature of engine oil 15 in an engine 11 capable of using alcohol fuel, a fuel detection means 305 detecting a first index value indicating the degree of the mixing of alcohol fuel in engine oil, and a water estimation means 306 estimating a second index value indicating the degree of the mixing of water in engine oil based on the detected temperature and the detected first index value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mixing estimation apparatus and method for estimating an index value that indicates at least the degree of mixing of water mixed in engine oil, for example, in a vehicle including an engine that can use alcohol fuel, and at least engine oil diluted with water. The present invention relates to an engine oil recovery device that recovers oil.

  When engine oil is diluted by mixing fuel and water in the engine in the engine, for example, the lubricity of the engine oil is reduced.

  In this kind of estimation device, for example, an increase amount of fuel for diluting the engine oil is calculated from the engine temperature, the engine speed and the engine load, and the calculated increase amount is integrated to dilute the engine oil. There is an oil dilution fuel estimation device that estimates the amount of fuel that is present (see Patent Document 1). Or there exists an oil dilution fuel estimation apparatus which calculates the fuel quantity which has diluted the engine oil according to the parameter | index set for every predetermined temperature range of the engine (refer patent document 2).

Japanese Patent Laid-Open No. 2004-137953 JP 2004-197591 A

  However, according to the background art described above, only the amount of fuel such as gasoline or heavy oil that is diluting the engine oil is estimated, and dilution of the engine oil due to mixing of water is not considered. That is, it is not possible to specify the degree of dilution of engine oil that is diluted with water (or diluted with at least alcohol and water that constitutes alcohol fuel), and the amount of such at least water mixed into engine oil. . Here, in particular, there is a technical problem that when the amount of water in the engine oil increases, there is a possibility that engine lubrication lowers, fuel consumption deteriorates, breakage, and the like occur. Further, when the amount of alcohol in the engine oil increases, there is a technical problem that the mixing of water into the engine oil is promoted.

  The present invention has been made in view of the above problems, for example, and provides a mixing estimation device and method for estimating at least an index value indicating the degree of mixing of water mixed into engine oil, and an engine oil recovery device. This is the issue.

  In order to solve the above-described problem, the contamination estimation apparatus of the present invention includes an oil temperature detection means for detecting the temperature of engine oil in an engine mounted on a vehicle and capable of using alcohol fuel, and the alcohol mixed in the engine oil. Fuel detection means for detecting a first index value indicating the degree of fuel mixing, and the degree of water mixing in the engine oil based on the detected temperature and the detected first index value Water estimation means for estimating the second index value.

  According to the contamination estimation device of the present invention, for example, when the engine that is mounted on a vehicle such as an automobile and is capable of using alcohol fuel is operating, the contamination estimation device includes at least a degree of contamination of water mixed in the engine oil. An index value indicating is estimated. Here, the “alcohol fuel” according to the present invention refers to a fuel obtained by mixing alcohol and another fuel such as gasoline (so-called alcohol mixed fuel), or a fuel containing only alcohol.

  The “index value” according to the present invention is typically a value that quantitatively indicates the degree of mixing of water or fuel mixed into the engine oil, and is a mixing amount or concentration. Means any physical quantity or parameter related to the mixing of water or fuel. The “mixing amount” may be a mixing amount or an absolute amount per unit amount of engine oil. In other words, it may mean a mixed amount in a broad sense. On the other hand, the “concentration” may be a percentage, a ratio, or a ratio. In other words, it may mean a broad concentration.

  Excess fuel dripped from between the cylinder and piston of the engine and water contained in the blow-by gas are mixed in the engine oil. According to the research of the present inventor, it is considered that there is a one-to-one correspondence between alcohol fuel and water mixed in engine oil because of the hydrophilic property of alcohol. Therefore, in the present invention, the second index value indicating the degree of mixing of water mixed in the engine oil is estimated by detecting the first index value indicating the degree of mixing of alcohol fuel mixed in the engine oil. Can do.

  The oil temperature detecting means detects the temperature of the engine oil. For example, the temperature of the engine oil may be detected directly by providing a temperature sensor in the oil pan of the engine, or may be detected indirectly from the coolant temperature, engine load, or the like. If the engine oil temperature is directly detected, the detection accuracy can be improved. On the other hand, if it detects indirectly, the existing water temperature sensor etc. can be diverted and a reduction in manufacturing cost can be expected.

  The fuel detection means detects a first index value indicating the degree of mixing of alcohol fuel mixed into the engine oil. For example, the first index value may be detected indirectly from the fuel injection amount, the temperature of the engine oil, or the like, or may be detected directly by providing an engine oil property sensor in the oil pan.

  The water estimation means estimates a second index value indicating the degree of water mixing into the engine oil based on the detected temperature of the engine oil and the detected first index value. Specifically, for example, the second index value may be obtained from a map that defines the relationship between the engine oil temperature and the second index value according to the first index value. Alternatively, the second index value may be obtained by a predetermined arithmetic expression. Such a map shows, for example, the relationship between the temperature of the engine oil and the second index value based on the results of simulations with various parameters such as the temperature of the engine oil, the alcohol concentration in the engine oil, and the solubility of water. What is necessary is just to specify and comprise.

  According to the present invention, since the hydrophilic alcohol is present in the engine oil, it is possible to appropriately deal with the water in the blowby gas that is likely to be mixed into the engine oil by estimating the index value related to the water. It is possible to prevent serious damage to the engine. Specifically, the engine can be prevented from being damaged, for example, by taking measures to evaporate water from the engine oil or alerting the operator according to the index value.

  In particular, in the case of using an alcohol fuel that has a larger fuel injection amount than gasoline fuel and water is likely to be mixed into engine oil, estimation of an index value related to at least water mixed into the engine oil is extremely desirable in practice. Specifically, for example, when the alcohol concentration in the fuel is close to 100%, a fuel injection amount that is about 1.5 times that of gasoline fuel is required in a warm state where the engine coolant temperature is 50 to 60 degrees Celsius. According to the research of the present inventor, it is necessary to have about 5 to 8 times as much fuel injection amount as that of gasoline fuel to start the engine at a low temperature where the outside air temperature is -10 to -20 degrees Celsius. It turns out.

  As a result, according to the mixing estimation device of the present invention, the first index value indicating the temperature of the engine oil and the degree of mixing of the alcohol fuel mixed in the engine oil is detected, and the detected temperature and the first index are detected. Based on the value, it is possible to estimate the second index value indicating the degree of water mixing into the engine oil.

  In one aspect of the contamination estimation apparatus of the present invention, the water estimation means includes a first level indicating a degree of change of the water mixed in the engine oil based on the detected temperature and the detected first index value. First change estimation means for estimating one change value is included, and the second index value is estimated by integrating the estimated first change values.

  According to this aspect, the first change estimating means estimates the first change value indicating the degree of change of water mixed in the engine oil based on the detected temperature of the engine oil and the detected first index value. To do. Here, the “change value” according to the present invention is typically a change amount or a change rate, and is a value corresponding to the physical quantity or parameter indicated by the index value. Specifically, for example, if the index value is a mixing amount, the change value indicates a changing amount or a changing rate of the mixing amount. For example, when the water mixed in the engine oil decreases, the change value indicates a negative value if the change value indicates an amount, and indicates a value less than 1 or a value less than 100% if the rate is a rate. It may be.

  The water estimation means integrates the first change values estimated by the first change estimation means regularly or irregularly to estimate a second index value indicating the degree of water mixing in the engine oil. . The water estimation means estimates the second index value by accumulating the first change value if the first change value indicates an amount, or multiplying the first change value if the first change value indicates a rate. .

  In another aspect of the contamination estimation apparatus of the present invention, the fuel detection means estimates a second change value indicating a change degree of the alcohol fuel mixed in the engine oil based on the detected temperature. 2 change estimation means is included, and the estimated second change value is integrated to detect the first index value.

  According to this aspect, the second change estimating means estimates the second change value indicating the degree of change of the alcohol fuel mixed in the engine oil based on the detected temperature of the engine oil. Specifically, for example, the second change value may be obtained from a map that defines the relationship between the engine oil temperature and the second change value. Alternatively, the second change value may be obtained by a predetermined arithmetic expression. Such a map may be configured by specifying the relationship between the temperature of the engine oil and the second change value from the result of a simulation in which parameters such as the temperature of the engine oil and the solubility of alcohol are variously changed. . The fuel detection means integrates the estimated second change value to detect the first index value.

  Thus, as long as the temperature of the engine oil is detected, the first and second index values can be obtained by a computer such as an ECU (Electronic Control Unit), which is very advantageous in practice.

  In the aspect of estimating the second change value, the second change estimation means includes a concentration detection means for detecting an alcohol concentration of the alcohol fuel, and further, based on the detected alcohol concentration, the second change value. Estimate the value.

  If comprised in this way, since the alcohol concentration in alcohol fuel is automatically detected by the concentration detection means, the estimation accuracy of the second change value can be improved. In addition, it is possible to save the operator or the like from examining or setting the alcohol concentration in the fuel used in advance. The alcohol constituting the alcohol fuel and other fuels such as gasoline have different boiling points, and the degree of fuel mixing varies depending on the alcohol concentration in the fuel. Therefore, by detecting the alcohol concentration in the fuel, the accuracy of estimation of the second change value and further the accuracy of the first and second index values are improved. For example, a warning is given even if the engine oil has not deteriorated. Or a warning after serious damage to the engine can be prevented.

  In another aspect of the contamination estimation apparatus of the present invention, the oil temperature detecting means includes water temperature detecting means for detecting a temperature of cooling water for cooling the engine, and based on the detected water temperature, the oil temperature of the engine oil is detected. Detect temperature.

  According to this aspect, the water temperature detecting means detects the water temperature of cooling water such as LLC (Long Life Coolant) that cools the engine, for example, at the outlet of the water jacket of the engine. The oil temperature detecting means obtains the temperature of the engine oil based on the detected water temperature, for example, by a predetermined arithmetic expression. Thus, for example, when designing an engine, there is no need to consider a temperature sensor for engine oil or wiring, which is very advantageous in practice.

  In order to solve the above problems, the contamination estimation method of the present invention includes an oil temperature detection step for detecting the temperature of engine oil in an engine mounted on a vehicle and capable of using alcohol fuel, and the alcohol contained in the engine oil. A fuel detection step for detecting a first index value indicating the degree of fuel mixing, and a degree of mixing of water contained in the engine oil based on the detected temperature and the detected first index value A water estimation step of estimating the second index value.

  According to the contamination estimation method of the present invention, it is possible to estimate an index value that indicates at least the degree of water contamination in the engine oil, as in the above-described contamination estimation apparatus of the present invention.

  Note that the contamination estimation method of the present invention can also adopt various aspects similar to the various aspects of the contamination estimation apparatus of the present invention described above.

  In order to solve the above-described problem, the engine oil recovery device of the present invention includes the above-described contamination estimation device of the present invention (including various aspects thereof), and the detected first index value is greater than a first threshold value. At least one of first determination means, second determination means for determining whether the estimated second index value is greater than a second threshold, and the first and second determination means Transition means for transitioning the vehicle to a recovery operation mode in which the temperature of the engine oil is raised when it is determined that the engine oil is large.

  According to the engine oil recovery device of the present invention, since the above-described contamination estimation device of the present invention is provided, it is possible to estimate the second index value indicating at least the degree of water contamination mixed into the engine oil. The first determination unit determines whether or not the detected first index value is greater than a first threshold value. The second determination unit determines whether or not the detected second index value is greater than a second threshold value. Here, the “first threshold value” and the “second threshold value” according to the present invention are predetermined threshold values related to the first and second index values used as the reference for determination by the first and second determination means. Typically, it is a mixing amount threshold value or a concentration threshold value. This threshold value is fixed in advance by experimentally or empirically obtaining data that is within a range that does not hinder the operation of the engine or the vehicle, or an allowable range, from data such as the amount of contamination and concentration obtained. A value may be set in advance. Alternatively, it may be set again at the time of maintenance, and further, for example, a variable value that changes in real time while the vehicle is running in consideration of other physical quantities or parameters such as the coolant temperature of the engine. Good.

  When the transition means determines that at least one of the first and second determination means is large, that is, the first threshold value corresponding to at least one of the detected first index value and the detected second index value, respectively. And when it determines with it being larger than a 2nd threshold value, a vehicle is made to transfer to recovery driving | operation mode. Here, the “recovery operation mode” according to the present invention refers to an operation mode in which the temperature of the engine oil is raised and the fuel and water mixed in the engine oil are evaporated. Specifically, for example, in consideration of the boiling point of ethanol mainly used for alcohol fuel, heating with a heater or the like is performed so that the temperature of the engine oil becomes 80 degrees Celsius. Alternatively, the engine load is increased, the engine temperature is increased, and the engine oil is heated.

  If the vehicle has a driving means such as an electric motor other than the engine, such as a hybrid vehicle, in order to increase the engine load, for example, the operating time of the engine is increased or the electric motor is used as a generator. It may be allowed to act.

  When it is determined that both the detected first index value and the detected second index value are smaller than the corresponding first and second threshold values, the transition means does not shift the vehicle to the recovery operation mode. Maintain normal operating mode.

  Thus, in the engine oil recovery device of the present invention, when it is determined that at least one of the first and second determination means is large, the operation shifts to the recovery operation mode. Therefore, according to the engine oil recovery device of the present invention, the first and second index values indicating the degree of mixing of fuel and water mixed into the engine oil can be reduced. As a result, the state of the engine oil can be maintained appropriately, and the engine can be prevented from being deteriorated due to an increase in friction, wear and rust in the engine. In particular, the engine oil can be kept in a good state in a vehicle such as a hybrid vehicle in which the engine is driven only for a short time, for example only during acceleration, and the engine is not warmed up sufficiently.

  In one aspect of the engine oil recovery device of the present invention, the transition means counts the number of times that the vehicle has transitioned to the recovery operation mode, and whether or not the counted number is greater than a third threshold. Third determining means for determining and warning means for giving a warning when it is determined that the counted number of times is greater than a third threshold value.

  According to this aspect, the counting means that is a counter, for example, counts the number of times that the vehicle has shifted to the recovery operation mode. The third determination means determines whether or not the counted number of transitions is greater than a third threshold value. Engine oil deteriorates due to, for example, oxidation or heat in addition to dilution with fuel and water. For this reason, the recovery operation can reduce the fuel and water mixed in the engine oil, but it is difficult to prevent natural deterioration of the engine oil due to causes other than dilution. Therefore, when the third determination unit determines that the counted number of transitions is larger than the third threshold value, the warning unit warns the operator, for example, that it is time to change the engine oil. Accordingly, the operator can easily know the deterioration of the engine oil or the time for replacing the engine oil, which is very advantageous in practice.

  The counting means according to the present invention may count the number of integrations that have shifted to the recovery operation mode, or may count the number of times that the transition has been made to the recovery operation mode continuously. Or you may measure the time which is performing recovery driving | operation instead of the frequency | count of transfer. For example, in a city area, a vehicle that is mainly used for short-distance movement may arrive at the destination during recovery operation, and the number of times of transition to recovery operation mode may increase. In such a case, if the time is measured by the counting means, it is possible to appropriately evaluate the deterioration of the engine oil. In addition, the “third threshold value” according to the present invention is a predetermined threshold value related to the number of times of transition or the recovery operation time, which is a criterion for determination by the third determination means, and is a threshold value of the number of transition times or a recovery operation time threshold value.

  In another aspect of the engine oil recovery device of the present invention, the transition means includes notification means for notifying that the vehicle has transitioned to the recovery operation mode.

  According to this aspect, the notification means notifies that the vehicle has shifted to the recovery operation mode or is in recovery operation. As a result, the operator or the like can know the state of the engine or the vehicle, which is very advantageous in practice. In particular, in a vehicle such as a hybrid vehicle, in which the normal engine operation time is short, the anxiety of the operator or the like due to the long engine operation time can be resolved.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, an embodiment according to an engine oil recovery device of the present invention will be described with reference to FIGS.

  First, the configuration of the engine oil recovery device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram of an engine oil recovery device according to the present embodiment.

  In FIG. 1, the engine oil recovery device is mounted on a vehicle including an engine 11 that uses alcohol fuel such as an automobile. The vehicle further includes an electric motor 40 and an ECU 30 configured to perform various electronic controls on the vehicle.

  The ECU 30 includes a command unit 301, a determination unit 302, an estimation unit 303, a memory 304, a fuel counter 305, a water counter 306, a transition counter 307, and an input / output circuit 308. The memory 304 is, for example, a nonvolatile memory such as an EEPROM (Electronically Erasable and Programmable Read Only Memory), a backup ROM, or a flash memory. The input / output circuit 308 inputs and outputs signals from each sensor and the like.

  The “command unit 301”, “determination unit 302”, “estimation unit 303”, “fuel counter 305”, “water counter 306”, and “transition counter 307” according to the present embodiment are respectively related to the present invention. It is an example of “transition means”, “first to third estimation means”, “first and second change estimation means”, “fuel detection means”, “water estimation means”, and “counting means”. In this embodiment, a part of the ECU 30 for various electronic controls is used as a part of the engine oil recovery device.

  The engine oil recovery device includes a mixing estimation device that estimates an amount of mixed water, which is an example of the “second index value” according to the present invention, which indicates at least the degree of mixing of water mixed into the engine oil 15, and the detected book A determination unit that determines whether or not the amount of mixed fuel that is an example of the “first index value” according to the invention is greater than a first threshold and whether or not the estimated amount of mixed water is greater than a second threshold 302, and a command unit 301 that shifts the vehicle to the recovery operation mode when it is determined that at least one of the mixed fuel amount and mixed water amount is larger than the corresponding first and second threshold values.

  The mixing estimation device is based on the oil temperature sensor 21 that detects the temperature of the engine oil 15, the fuel counter 305 that detects the amount of mixed fuel mixed in the engine oil 15, the detected temperature, and the detected mixed fuel amount. An estimation unit 303 that estimates the amount of change in water, which is an example of the “first change value” according to the present invention and indicates the degree of change in water mixed in the engine oil 15, and the estimated amount of change in water is integrated. And a water counter 306 for estimating the amount of water mixed in the engine oil 15.

  The estimation unit 303 is a fuel that is an example of a “second change value” according to the present invention that indicates the degree of change in alcohol fuel mixed into the engine oil 15 based on the temperature detected by the oil temperature sensor 21. Estimate the amount of change. The fuel counter 305 integrates the estimated fuel change amount to detect the amount of mixed fuel.

  The mixing estimation apparatus further includes a concentration sensor 24 that detects the alcohol concentration in the alcohol fuel in the fuel tank 18. Instead of detecting the temperature of the engine oil 15 by the oil temperature sensor 21, the water temperature of the cooling water 16 of the engine 11 is detected by the water temperature sensor 22, and the temperature of the engine oil 15 is detected based on the detected water temperature. May be.

  The engine oil recovery device further counts the number of times of transition to the recovery operation mode, a drain plug 23 provided in the oil pan 13 of the engine 11, an information display 51 and a speaker 52 for notifying the operator of the vehicle state, and the like. And a transition counter 307. Here, the information display 51 and the speaker 52 according to the present embodiment are examples of the “notification unit” and the “warning unit” according to the present invention.

  Here, a method of detecting or estimating the amount of mixed fuel and the amount of mixed water in the ECU 30 including the fuel counter 305 and the water counter 306 will be described with reference to FIGS.

  FIG. 2 is an example of a map that defines the relationship between the amount of fuel dripped onto the engine oil 15 and the temperature of the engine oil 15 when the engine is started. FIG. 3 is an example of a map that defines the relationship between the amount of fuel dripped onto the engine oil 15 and the temperature of the engine oil 15 during engine operation. FIG. 4 is an example of a map that defines the relationship between the amount of fuel evaporated from the engine oil 15 and the temperature of the engine oil 15. Here, a solid line in FIGS. 2 to 4 indicates a case where the alcohol concentration in the alcohol fuel is a high concentration such as about 100%, and a broken line indicates a case where the alcohol concentration is a medium concentration where the alcohol concentration is 20 to 50%, for example. Each shows.

  FIG. 5 is an example of a map that defines the relationship between the increase / decrease amount of water mixed in the engine oil 15 and the temperature of the engine oil 15. Here, the solid line in FIG. 5 indicates the case where the concentration of the alcohol fuel in the engine oil 15 is high, for example, 1 to 2%, and the broken line indicates the concentration of the alcohol fuel, for example, 0.2 to 0.8%. Each case of a certain medium concentration is shown.

  The value on the vertical axis in FIGS. 2 to 5 may be the amount of fuel or moisture per unit volume, or may be an absolute amount. Further, the horizontal axis may be the water temperature of the cooling water 16. These maps are obtained from simulation results obtained by variously changing parameters such as engine oil temperature, alcohol concentration in engine oil, water and fuel solubility, and fuel injection amount. What is necessary is just to identify and configure the relationship between parameters. Or what is necessary is just to comprise by experiment.

  When the engine 11 is started or operated, surplus fuel out of the fuel injected from the fuel injection valve 17 drops into the engine oil 15 from between the cylinder 12 and the piston 14. Therefore, first, the operation state of the engine 11 is determined by the determination unit 302. The estimation unit 303 selects a map as shown in FIGS. 2 and 3 stored in the memory 304 according to the determined operation state, and the temperature of the engine oil 15 detected by the oil temperature sensor 21, and Based on the alcohol concentration in the alcohol fuel detected by the concentration sensor 24, the amount of fuel dripped onto the engine oil 15 is estimated.

  Specifically, when the engine 11 is started, the estimation unit 303 selects a map as shown in FIG. 2 stored in the memory 304, and estimates the amount of fuel dripped onto the engine oil 15 from the map. When the engine 11 is in operation, the estimation unit 303 selects a map as shown in FIG. 3 stored in the memory 304 and estimates the amount of fuel dripped onto the engine oil 15 from the map. When the engine 11 is stopped, there is no fuel injection from the fuel injection valve 17, so the estimation unit 303 sets the amount of dropped fuel to zero.

  The estimation unit 303 further selects a map as shown in FIG. 4 stored in the memory 304, and estimates the amount of fuel evaporated from the engine oil 15 based on the temperature and alcohol concentration of the engine oil 15. Here, in FIG. 4, a positive value indicates the evaporated fuel amount, and a negative value indicates the liquefied fuel amount. If the temperature of the engine oil 15 increases, the amount of fuel that evaporates increases. However, if the temperature decreases, the fuel liquefies and mixes into the engine oil 15 along the inner wall of the cylinder 12, for example.

  The estimation unit 303 obtains the fuel change amount by taking the difference between the dripping fuel amount and the evaporating fuel amount. The fuel counter 305 integrates the obtained fuel change amount and detects the mixed fuel amount. In the map as shown in FIG. 4, if the evaporated fuel amount is indicated by a negative value, the estimating unit 303 calculates the sum of the dripping fuel amount and the evaporated fuel amount and calculating the fuel change amount. Ask.

  The estimation unit 303 selects a map as shown in FIG. 5 stored in the memory 304, and estimates the amount of moisture change based on the temperature of the engine oil 15 and the amount of mixed fuel. Here, in FIG. 5, a positive value indicates an increased amount of water, and a negative value indicates a decreased amount of water.

  If the temperature of the engine oil 15 increases, the water evaporates, so the moisture in the engine oil 15 decreases. If the temperature decreases, the water vapor liquefies and mixes into the engine oil 15, so that the moisture increases. In FIG. 5, the amount of water suddenly increases in the low temperature range and the amount of water drastically decreases in the high temperature range because the amount of fuel (particularly the amount of alcohol) mixed in the engine oil 15 changes greatly. Due to The water counter 306 accumulates the estimated water change amount to estimate the mixed water amount.

  Returning to FIG. 1 again, the determination unit 302 in the ECU 30 determines whether the detected mixed fuel amount and the estimated mixed water amount are larger than the corresponding first threshold value and second threshold value, respectively. When it is determined that at least one of the mixed fuel amount and the mixed water amount is larger than the corresponding first threshold value and second threshold value, the command unit 301 increases the load of the engine 11 to increase the temperature of the engine oil 15. The vehicle is shifted to a recovery operation mode that raises the vehicle.

  When the command unit 301 shifts the vehicle to the recovery operation mode, for example, the information display 51 in the instrument panel displays that the recovery operation is being performed, and notifies the operator or the like. The transition counter 307 counts the number of times of transition to the recovery operation mode.

  When it is determined that both the mixed fuel amount and the mixed water amount are smaller than the corresponding first threshold value and second threshold value, the command unit 301 does not shift the vehicle to the recovery operation mode, but the engine 11 or the electric motor. 40, or the normal operation mode in which the engine 11 and the electric motor 40 are used in combination is maintained.

  The determination unit 302 determines whether or not the number of transitions counted by the transition counter 307 is greater than the third threshold value. When it is determined that the number of times of transition is greater than the third threshold value, the command unit 301 displays, for example, an information display 51 in the instrument panel indicating that it is time to replace the engine oil 15 and from the speaker 52 a voice or alarm Is output and a warning is given to the operator.

  Next, the estimated mixing recovery process executed by the ECU 30 in the vehicle equipped with the engine oil recovery apparatus configured as described above will be described with reference to the flowcharts of FIGS. This contamination estimation recovery process is performed periodically, for example, periodically or irregularly every few seconds to every few seconds while the vehicle is traveling.

  In FIG. 6, first, the amount of mixed fuel and the amount of mixed water are estimated by the mixing estimation process (step S100).

  Here, the mixing estimation process will be described with reference to FIG. First, the concentration sensor 24 detects the alcohol concentration in the alcohol fuel in the fuel tank 18 (step S101). Next, the oil temperature sensor 21 detects the temperature of the engine oil 15 (step S102). Next, the determination unit 302 determines whether or not it is at the start of the engine 11 (step S103).

  When the engine 11 is being started (step S103: Yes), the estimating unit 303 stores the amount of fuel dripped into the engine oil 15 and the engine oil 15 stored in the memory 304 as shown in FIG. A map that defines the relationship with the temperature of the engine oil 15 is selected (step S104), and the amount of fuel dripped onto the engine oil 15 is estimated based on the detected temperature of the engine oil 15 and the detected alcohol concentration (step S107). .

  When it is not at the time of starting the engine 11 (step S103: No), it is subsequently determined whether or not the engine 11 is in operation (step S105). When the engine 11 is in operation (step S105: Yes), the estimation unit 303 stores the amount of fuel dripped into the engine oil 15 and the engine oil 15 stored in the memory 304 as shown in FIG. A map that defines the relationship with the temperature of the engine oil 15 is selected (step S106), and based on the detected temperature of the engine oil 15 and the detected alcohol concentration, the amount of fuel that drops on the engine oil 15 is estimated (step S107). . If it is not during operation of the engine 11 (step S105: No), the process of step S108 is performed.

  Next, the estimation unit 303 selects a map that defines the relationship between the amount of fuel evaporated from the engine oil 15 and the temperature of the engine oil 15 as shown in FIG. 4 stored in the memory 304 (step S108). Based on the detected temperature of the engine oil 15 and the detected alcohol concentration, the amount of fuel evaporated from the engine oil 15 is estimated (step S109). The estimation unit 303 calculates the fuel change amount by taking the difference between the fuel amount to be dropped and the fuel amount to be evaporated, and the fuel counter 305 integrates the obtained fuel change amount to detect the mixed fuel amount ( Step S110).

  Next, the estimation unit 303 selects a map that defines the relationship between the increase / decrease amount of water mixed in the engine oil 15 and the temperature of the engine oil 15 as shown in FIG. Step S111), the amount of moisture change is estimated based on the temperature of the engine oil 15 and the amount of mixed fuel (step S112). The water counter 306 accumulates the estimated water change amount and estimates the mixed water amount (step S113).

  Returning to FIG. 6 again, the determination unit 302 determines whether or not the recovery operation flag indicating that the vehicle is in the recovery operation mode is ON (step S201). When the recovery operation flag is not ON (step S201: No), that is, when the vehicle is in the normal operation mode, it is next determined whether or not the amount of mixed fuel is larger than the first threshold (step S202). When it is determined that the mixed fuel amount is smaller than the first threshold (step S202: No), it is subsequently determined whether the mixed water amount is larger than the second threshold (step S203).

  When it is determined that the amount of mixed fuel is greater than the first threshold (step S202: Yes), or when it is determined that the amount of mixed water is greater than the second threshold (step S203: Yes), the command unit 301 detects the vehicle. A transition to the recovery operation mode is made and a message to that effect is displayed on the monitor 51, and the transition counter 307 counts the number of transitions (step S207).

  When it is determined that the amount of mixed water is smaller than the second threshold (step S203: No), the vehicle maintains the normal operation mode (step S204), and the process is temporarily terminated.

  When the recovery operation flag is ON (step S201: Yes), the determination unit 302 determines whether the mixed fuel amount is smaller than the first threshold value −α. Here, α is a guaranteed value, which is the minimum amount of fuel evaporated by the recovery operation. Thus, it is possible to prevent a transition to the recovery operation mode immediately after the recovery operation is completed. The guaranteed value α may be a fixed value, or may be a variable value corresponding to the temperature of the engine oil 15 or the like, for example.

  When it is determined that the mixed fuel amount is smaller than the first threshold value −α (step S205: Yes), it is subsequently determined whether or not the mixed water amount is smaller than the second threshold value −β (step S206). Here, β is a guaranteed value having the same meaning as α, may be a fixed value, or may be a variable value corresponding to the temperature of the engine oil 15 or the like, for example. When it is determined that the amount of mixed water is smaller than the second threshold value −β (step S206: Yes), the command unit 301 shifts the vehicle to the normal operation mode (step S204), and temporarily ends the process.

  When it is determined that the mixed fuel amount is larger than the first threshold value −α (step S205: No), or when it is determined that the mixed water amount is larger than the second threshold value −β (step S206: No), recovery is performed. Operation is maintained (step S207).

  The determination unit 302 determines whether or not the number of transitions counted by the transition counter 307 is greater than the third threshold (step S208). If the number of times of transition is smaller than the third threshold (step S208: No), the process is once terminated. If the number of times of transition is larger than the third threshold value (step S208: Yes), the command unit 301 displays the fact on the monitor 51 and outputs a sound or an alarm from the speaker 52 to warn the operator or the like (step) S209).

  Next, the determination unit 302 determines whether or not the engine oil 15 has been replaced (step S210). Whether or not the engine oil 15 has been replaced is determined by whether or not the drain plug 23 provided in the oil pan 13 is previously supplied with current and the drain plug 23 is removed when the engine oil 15 is replaced. It is sufficient to detect and determine that no current flows. Alternatively, it may be determined by a change in the oil level gauge, or may be manually input by an operator after the engine oil 15 is replaced.

  When the engine oil 15 is replaced (step S210: Yes), the command unit 301 initializes the values of the fuel counter 305, the water counter 306, and the transition counter 307 (step S211), and the process is temporarily terminated. If the engine oil 15 is not replaced (step S210: No), the process is temporarily terminated.

  As described above, according to the present embodiment, the amount of mixed fuel and the amount of mixed water mixed in the engine oil 15 can be estimated based on the temperature of the engine oil 15 and the alcohol concentration in the alcohol fuel. Furthermore, by performing a recovery operation in which the temperature of the engine oil 15 rises, the amount of mixed fuel and the amount of mixed water can be reduced.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The estimation device and method and the engine oil recovery device are also included in the technical scope of the present invention.

It is a block diagram of an engine oil recovery device concerning an embodiment of the present invention. It is an example of the map which defines the relationship between the fuel quantity dripped at engine oil at the time of engine starting, and the temperature of engine oil. It is an example of the map which defines the relationship between the fuel quantity dripped at engine oil at the time of engine operation, and the temperature of engine oil. It is an example of the map which defines the relationship between the fuel amount evaporated from engine oil, and the temperature of engine oil. It is an example of the map which defines the relationship between the increase / decrease amount of the water mixed in engine oil, and the temperature of engine oil. It is a flowchart which shows the mixing estimation recovery process in ECU which concerns on embodiment of this invention. It is a flowchart which shows the mixing estimation process in ECU which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Cylinder, 13 ... Oil pan, 14 ... Piston, 15 ... Engine oil, 16 ... Cooling water, 17 ... Fuel injection valve, 18 ... Fuel tank, 21 ... Oil temperature sensor, 22 ... Water temperature sensor, 23 ... Drain plug, 24 ... Concentration sensor, 30 ... ECU, 40 ... Electric motor, 51 ... Information display, 52 ... Speaker

Claims (9)

Oil temperature detection means for detecting the temperature of engine oil in an engine mounted on a vehicle and capable of using alcohol fuel;
Fuel detection means for detecting a first index value indicating a degree of mixing of the alcohol fuel mixed in the engine oil;
Water mixing means for estimating a second index value indicating a degree of mixing of water mixed into the engine oil based on the detected temperature and the detected first index value. Estimating device. The water estimation means includes
First change estimation means for estimating a first change value indicating a degree of change of the water mixed in the engine oil based on the detected temperature and the detected first index value;
The contamination estimation apparatus according to claim 1, wherein the second index value is estimated by integrating the estimated first change value. The fuel detection means includes
A second change estimating means for estimating a second change value indicating a degree of change of the alcohol fuel mixed in the engine oil based on the detected temperature;
The contamination estimation apparatus according to claim 1, wherein the first index value is detected by integrating the estimated second change values. The second change estimating means includes
A concentration detecting means for detecting the alcohol concentration of the alcohol fuel;
The contamination estimation apparatus according to claim 3, further comprising estimating the second change value based on the detected alcohol concentration. The oil temperature detecting means is
Water temperature detecting means for detecting the temperature of cooling water for cooling the engine,
The contamination estimation apparatus according to any one of claims 1 to 4, wherein a temperature of the engine oil is detected based on the detected water temperature. An oil temperature detection process for detecting the temperature of engine oil in an engine mounted on a vehicle and capable of using alcohol fuel;
A fuel detection step of detecting a first index value indicating a degree of mixing of the alcohol fuel contained in the engine oil;
A water estimation step of estimating a second index value indicating a degree of mixing of the water contained in the engine oil based on the detected temperature and the detected first index value. Contamination estimation method. The contamination estimation device according to any one of claims 1 to 5,
First determination means for determining whether or not the detected first index value is greater than a first threshold;
Second determination means for determining whether or not the estimated second index value is greater than a second threshold;
Engine oil recovery comprising: a transition means for shifting the vehicle to a recovery operation mode for raising the temperature of the engine oil when it is determined that at least one of the first and second determination means is large. apparatus. The transition means includes
Counting means for counting the number of times the vehicle has entered the recovery operation mode;
Third determination means for determining whether or not the counted number is greater than a third threshold;
The engine oil recovery device according to claim 7, further comprising: a warning unit that issues a warning when it is determined that the counted number is greater than a third threshold. The transition means includes
The engine oil recovery device according to claim 7 or 8, further comprising notification means for notifying that the vehicle has shifted to the recovery operation mode.

Images