JP4825156B2 - Engine oil condition monitoring device - Google Patents

Description

  The present invention relates to an engine oil state monitoring device that monitors an engine oil state of an engine.

  The engine is configured to suck up engine oil having a lubricating action from an oil pan during operation of the engine to lubricate a necessary portion and then return the oil to the oil pan.

The above-mentioned engine oil deteriorates when exposed to high temperatures, etc., or is released into the atmosphere together with exhaust gas and consumed. Various devices for monitoring the oil state such as the degree of deterioration and remaining amount of engine oil It has been known.
For example, as a device that warns the engine oil replacement time according to the prediction corresponding to the degree of deterioration of the engine oil, the accumulated operation time of the engine, which is the accumulated operation time corrected by the load factor, has exceeded the engine oil replacement reference time limit In some cases, an apparatus that displays an alarm is known (see Patent Document 1).
Further, as a device that can know an appropriate remaining amount of engine oil, a device provided with a level sensor that detects an oil level in an oil pan is known (see Patent Document 2).

JP-A-7-208140 JP-A-5-288031

In the apparatus of Patent Document 1, even if the same type of engine is used, the engine oil replacement reference time limit is uniformly determined despite differences in the consumption speed of the engine oil due to individual differences in manufacturing. Yes. Therefore, even when the amount of engine oil consumption is small and the deterioration level of the engine oil is low, the oil is not replaced even if the oil is replaced wastefully or even when the consumption amount is high and the deterioration level is high. There were problems such as causing engine failure.
In addition, the level sensor that can withstand the heat of the engine provided in the device of Patent Document 2 is merely a sensor that detects whether or not the remaining amount of oil has decreased to a predetermined level, for example, and continuously determines the remaining amount of oil. It is not something that can be detected. Furthermore, such a level sensor has not been practical because there are many false detections due to vibration.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an oil state monitoring device that can accurately recognize the oil state such as the remaining amount of engine oil and the degree of deterioration with a simple configuration. The point is to provide.

  The engine oil condition monitoring device for monitoring the engine oil condition of the engine according to the present invention for achieving the above object is based on the knowledge that there is a correlation between the remaining amount of engine oil and the rate of increase in oil temperature, The first characteristic configuration is an oil temperature measuring means for measuring an oil temperature that is the temperature of the engine oil, and a rate of increase in the oil temperature based on a measurement result of the oil temperature measuring means during the warm-up operation of the engine. Oil temperature rise rate deriving means, and oil state estimation means for estimating an oil state corresponding to the remaining amount of engine oil from the oil temperature rise rate derived by the oil temperature rise rate deriving means. It is in the point.

According to the first characteristic configuration, the oil temperature increase rate deriving unit determines the oil temperature increase rate based on the measurement result of the oil temperature measurement unit during the warm-up operation in which the engine shifts from the cold state to the warm state. Therefore, the oil state estimation means estimates the oil state corresponding to the remaining amount of engine oil from the rising speed of the oil temperature, so that the oil state corresponding to the remaining amount of engine oil can be obtained without providing an expensive level sensor. It can be estimated accurately. In the present application, the warm-up operation refers to an operation in which the engine shifts from the cold state to the warm state with the same output or output fluctuation pattern every time.
That is, the heat capacity of the engine oil is approximately proportional to the remaining amount of engine oil, and the heat generation of the engine during warm-up operation is almost constant. There is a predetermined correlation with the remaining amount of engine oil, such that the greater the remaining amount, the slower. Therefore, the remaining amount of engine oil or the corresponding oil state can be accurately estimated from the rate of increase in the oil temperature during the warm-up operation.
Further, since the engine oil replacement time can be determined as an appropriate time based on the accurate estimation result of the oil state, it is possible to prevent unnecessary engine oil replacement while preventing engine failure due to deterioration of the engine oil.
Accordingly, it is possible to realize a state monitoring device capable of accurately recognizing the oil state such as the remaining amount and deterioration degree of the engine oil with a simple configuration that does not require an engine oil level sensor.

  The engine oil condition monitoring apparatus according to a second aspect of the present invention is characterized in that, in addition to the first characteristic structure, the oil condition estimating means estimates the oil condition based on the engine temperature condition. The oil condition reference value is determined.

  According to the second characteristic configuration, the oil state reference value of the oil temperature rising speed for estimating the oil state described above is an engine temperature state that changes according to environmental conditions such as an installation location, an operation timing, and an operation load. Since it is determined appropriately in consideration, the accuracy of estimation of the oil state can be further increased in a form that eliminates the estimation error due to the change in the environmental condition.

  As described above, the rising speed of the oil temperature is related to the remaining amount of engine oil. At this time, the rising speed of the oil temperature is governed by environmental conditions under the situation where the engine is placed. Therefore, the rising speed of the cooling water temperature or the environmental temperature can be used as an index representing the environmental condition.

A third characteristic configuration of the engine oil state monitoring apparatus according to the present invention includes a cooling water temperature measuring means for measuring a cooling water temperature, which is a temperature of the cooling water of the engine, in addition to the second characteristic configuration, and the warm-up operation. Cooling water temperature rise speed deriving means for deriving the rising speed of the cooling water temperature as the engine temperature state based on the measurement result of the cooling water temperature measuring means at the time, the oil state estimating means, The oil state reference value is determined based on the cooling water temperature rising speed derived by the cooling water temperature rising speed deriving means.

According to the third characteristic configuration, the oil state can be estimated with higher accuracy by determining the oil state reference value based on the rising speed of the cooling water temperature.
And the oil condition reference value determined according to the environmental condition from the rising speed of the cooling water temperature as the engine temperature condition influenced by the actual environmental condition, and the oil temperature affected by the actual environmental condition. The oil state according to the remaining amount of oil can be estimated with high accuracy in a form that eliminates the influence of actual environmental conditions using the rising speed.

The fourth characteristic feature of the engine oil condition monitoring apparatus according to the present invention, in addition to the second feature configuration, internal or external temperature of the casing of the engine during the warm-up operation, the engine during the warm-up operation An environmental temperature measuring means for measuring an environmental temperature that is one of a cooling water temperature that is a cooling water temperature or an exhaust gas temperature of the engine during the warm-up operation as a temperature state of the engine ;
The oil state estimating means determines the oil condition reference value based on the environmental temperature measured by the environmental temperature measuring means.

According to the fourth characteristic configuration, it is possible to estimate the oil state with higher accuracy by determining the oil state reference value based on the environmental temperature.
In this case, as the engine temperature state , the temperature inside or outside the casing of the engine during the warm-up operation, the coolant temperature that is the temperature of the engine coolant during the warm-up operation, or the exhaust gas of the engine during the warm-up operation An environmental temperature that is any one of the temperatures shall be used.
Therefore, by using the oil condition reference value determined according to the actual environmental temperature and the rising speed of the oil temperature that is also affected by the actual environmental temperature, the effect of the actual environmental temperature is eliminated, The oil state corresponding to the remaining amount of oil can be estimated with high accuracy.

The fifth characteristic configuration of the engine oil condition monitoring apparatus according to the present invention, in addition to any one of the fourth characterizing feature of the first feature structure, and a measurement result of the oil temperature measuring means at the time of the warm-up operation, et This is in that the measurement result of the oil temperature measuring means at the time of the operation of shifting the engine from the cold state to the warm state is used.

According to the fifth characteristic configuration, since the measurement result of the oil temperature measurement unit during the warm-up operation is used as the measurement result of the oil temperature measurement unit during the operation in which the engine shifts from the cold state to the warm state, The rising speed of the oil temperature can be accurately obtained.

  According to a sixth characteristic configuration of the engine oil condition monitoring apparatus of the present invention, in addition to any one of the first to fifth characteristic structures, the oil condition estimation means includes the oil temperature rising speed and the engine oil. The remaining amount of the engine oil as the oil state is estimated using a correlation with the remaining amount.

  According to the sixth characteristic configuration, the oil temperature rising speed and the remaining amount of engine oil have a correlation. Therefore, the oil temperature rising speed deriving means is derived using the correlation obtained in advance. The remaining amount of engine oil as an oil state can be estimated from the rising speed of the oil temperature.

  According to a seventh characteristic configuration of the engine oil condition monitoring apparatus according to the present invention, in addition to any of the first characteristic structure to the sixth characteristic structure, the oil condition estimation means includes a remaining amount of engine oil, an accumulated usage time, This is in that the degree of deterioration of the engine oil as the oil state is estimated using the correlation with the degree of deterioration.

  According to the seventh characteristic configuration, the amount of engine oil consumed since the previous replacement can be recognized from the remaining amount of engine oil, and the amount of oil consumed and the accumulated operation time of the engine since the previous replacement. The accumulated usage time of the engine oil has a correlation with the degree of deterioration of the engine oil, so that the correlation is obtained in advance, and using this, the remaining amount of engine oil derived by the oil state estimating means is used. From the accumulated use time of the engine oil at that time, the degree of deterioration of the engine oil as an oil state can be obtained.

  The eighth characteristic configuration of the engine oil condition monitoring apparatus according to the present invention performs a notification process for the user in accordance with the estimation result of the oil condition estimation means in addition to any of the first characteristic configuration to the seventh characteristic configuration. It is in the point provided with the reporting means.

  According to the eighth characteristic configuration, the notifying unit outputs an appropriate message to the user according to the oil state such as the remaining amount of engine oil or the degree of deterioration of the engine oil described above. Therefore, even a user who is unfamiliar with oil change or the like can accurately grasp the oil state from the message.

  A ninth characteristic configuration of the engine oil condition monitoring device according to the present invention is configured to determine whether or not the engine can be operated according to an estimation result of the oil condition estimation means in addition to any of the first to eighth characteristic structures. The engine operation control means is provided.

  According to the ninth feature, the engine operation control means automatically stops the engine operation when it is estimated that an oil state such as the remaining amount of the engine oil or the degree of deterioration of the engine oil is unacceptable. Thus, engine failure can be prevented appropriately.

  An embodiment of an engine oil state monitoring device 100 of the present invention will be described based on the drawings.

FIG. 1 shows a configuration of an engine system 100 including an engine oil state monitoring device that monitors the state of the engine oil O of the engine 1.
The engine 1 is provided in a casing 7 and is configured as a spark ignition engine that sparks an air-fuel mixture by a spark plug 2. This type of engine 1 includes an oil pan 3 that stores engine oil O that lubricates main parts, and a cooling water circulation path 5 that circulates cooling water JW and cools the engine 1. The cooling water circulation path 5 is provided with a radiator 4 that cools the cooling water JW that has been heated by cooling the engine 1 and a circulation pump 6 that circulates the cooling water JW between the engine 1 and the radiator 4.
Further, the operation of the engine 1 is controlled by an engine operation control means 23 functioning by a control device 20 composed of a computer. For example, the engine operation control means 23 stops the spark ignition of the spark plug 2 so that the engine 1 is operated. Can be stopped.

Furthermore, the engine system 100 includes an oil temperature sensor 11 in the oil pan 3 as an oil temperature measuring unit that measures an oil temperature that is the temperature of the engine oil O.
The control device 20 is derived by an oil temperature rise speed deriving means 21 for deriving the oil temperature rise speed based on the measurement result of the oil temperature sensor 11 during the warm-up operation of the engine 1, and the oil temperature rise speed deriving means 21. It functions as oil state estimating means 30 for estimating the oil state corresponding to the remaining amount of engine oil O from the rising speed of the oil temperature.
The remaining amount of the engine oil O and the degree of deterioration of the engine oil O are obtained from the remaining amount of the engine oil O or the remaining amount in the present invention. It can be said that the oil state corresponds to.
That is, in the present embodiment, the oil state represents the remaining amount of engine oil O and the degree of deterioration of engine oil O. Further, as the measurement result at the time of warm-up operation in which the engine 1 shifts from the cold state to the warm state, the above oil is used by using the measurement result at the start-up operation from the start of the operation of the engine 1 in the cold state. The temperature rise rate and the cooling water temperature rise rate described later are derived.

  Further, the oil state estimation means 30 includes a reference value determination unit 32 that appropriately determines an oil state reference value serving as a reference for estimating the oil state in consideration of the engine temperature state, and the oil state reference value and the oil temperature. The degree of deterioration of the engine oil O is estimated from the remaining oil amount estimation unit 31 that estimates the remaining amount of the engine oil O from the rising speed, and the remaining amount of the engine oil O and the accumulated usage time of the engine oil O at that time. And a storage unit 34 that holds a function for estimating the oil state, data acquired in advance, and the like.

  The reference value determination unit 32 determines the oil state reference value according to the environmental condition from the rising speed of the cooling water temperature affected by the actual environmental condition.

  The oil remaining amount estimating unit 31 estimates the remaining amount of the engine oil O using the oil state reference value determined by the reference value determining unit 32 and the oil temperature rising speed influenced by actual environmental conditions. To do. The estimation is performed using an oil remaining amount derivation function described later.

  The oil deterioration level estimation unit 33 estimates the deterioration level of the engine oil O from the remaining amount of the engine oil O of the remaining oil amount estimation unit 31 and the accumulated usage time of the engine oil O at that time. The estimation is performed using an oil deterioration degree derivation function described later.

  Note that the above two functions are determined based on various data acquired in advance through experiments or the like and stored in the storage unit 34.

  A cooling water temperature sensor 12 is provided between the engine 1 and the radiator 4 in the cooling water circulation path 5 described above, and this functions as a cooling water temperature measuring means for measuring the cooling water temperature after leaving the engine 1.

  The control device 20 functions as a cooling water temperature increase rate deriving unit 22 that derives the increase rate of the cooling water temperature based on the measurement result of the cooling water temperature sensor 12.

  The control device 20 functions as a notification unit 24 that notifies the user of the remaining amount of the engine oil O that is in the oil state and the estimation result of the degree of deterioration of the engine oil O. The notification unit 24 instructs the speaker 51 and the display unit 52, which are external devices, to perform audio output and display output based on the oil state.

  The engine operation control means 23 determines whether or not the engine 1 can be operated based on the estimation result of the remaining amount of the engine oil O in the oil state and the degree of deterioration of the engine oil O. Is configured to stop.

Hereinafter, the determination process of the oil condition reference value and the oil remaining amount derivation function will be described with reference to FIG.
FIG. 2 shows the oil temperature and the cooling water temperature when the engine oil O remains in a large amount and a small amount when the engine in the cold state shifts from the cold state to the warm state during start-up operation. The oil temperature (Hi) bold line represents the change over time of the oil temperature when the remaining amount of engine oil O is large, and the oil temperature ( Lo) represents a change over time in the oil temperature when the remaining amount of engine oil O is low, and the dotted line of the cooling water temperature (Hi) represents the temperature of the cooling water when the remaining amount of engine oil O is large. The change with time is shown, and the thin solid line of the coolant temperature (Lo) shows the change with time of the coolant temperature when the remaining amount of engine oil O is small.

  By comparing the oil temperature (Hi) and the oil temperature (Lo), the remaining amount of engine oil O and the rising speed of the oil temperature indicate that the lower the remaining amount of engine oil O, the faster the rising speed of the oil temperature. It can be seen that there is a correlation.

That is, the correlation is obtained by subtracting the oil temperature increase speed from the oil condition reference value and the engine oil by using the oil condition reference value representing the oil temperature increase speed in a certain reference remaining amount under a certain environmental condition. It is represented by the correlation with the remaining amount of O.
In the present embodiment, the reference remaining amount is a lower limit value of the remaining amount of engine oil O. Of course, the reference remaining amount may be a value other than the lower limit value.
Here, when the case where the remaining amount of engine oil O is the lower limit value and the environmental temperature is about 26 ° C. is defined as the standard state, the oil state reference value in the actual environmental condition is the oil in the standard state obtained in advance through experiments or the like The temperature increasing rate is determined by correcting the difference between the cooling water temperature increasing rate in the standard state and the cooling water temperature increasing rate under actual environmental conditions. In addition, without performing such correction, the respective oil state reference values at a plurality of different rising temperatures of the cooling water temperature are obtained in advance through experiments or the like, and the obtained plurality of oil state reference values are calculated based on the cooling water temperature. Map data compiled for each rising speed may be created, and the actual cooling water temperature rising speed may be applied to the map data to derive the oil condition reference value under actual environmental conditions.

  The basis for this will be described below. Comparing the cooling water temperature (Hi) and the cooling water temperature (Lo), it can be seen that the rising speed of the cooling water temperature is almost constant regardless of the remaining amount of the engine oil O. Further, the rising speed of the cooling water temperature fluctuates according to the change of the environmental conditions, like the rising speed of the oil temperature. Due to these two facts, the difference between the rising speed of the cooling water temperature in the standard state and the rising speed of the cooling water temperature under the actual environmental conditions represents the influence of fluctuations in the environmental conditions that are not affected by the remaining amount of the engine oil O. Therefore, from this difference and the rising speed of the oil temperature in the standard state, the rising speed of the oil temperature under actual environmental conditions can be obtained as the oil state reference value.

  For example, the oil condition reference value is obtained by subtracting the cooling water temperature rising speed from the cooling water temperature rising speed when the remaining amount of engine oil O is the lower limit and the environmental temperature is about 26 ° C. On the other hand, it is determined by multiplying the specific heat of the cooling water JW by the specific heat of the engine oil O and adding the rate of increase of the oil temperature in the standard state.

  From the above, the oil remaining amount derivation function is a function having a correlation that the remaining amount of engine oil O increases as the rate of increase in the oil temperature decreases. For example, in actual environmental conditions, the correlation between the reference remaining amount and the reference remaining amount depends on how slow the oil temperature rise rate in the actual remaining amount of engine oil O is relative to the oil state reference value in the remaining reference amount. It is possible to determine how much the actual remaining amount of engine oil O is, and by adding the reference remaining amount to the value, an estimation result of the remaining amount of engine oil O can be obtained.

That is, the remaining amount of engine oil O can be obtained from the above-described oil state reference value, the oil remaining amount derivation function, and the derived rate of increase in the oil temperature under actual environmental conditions.
In addition, each oil state reference value at a plurality of different reference remaining amounts is obtained in advance through experiments, etc., and map data is created in which the obtained plurality of oil state reference values are summarized for each reference remaining amount. The actual remaining amount of engine oil O may be derived by applying the rising speed of the oil temperature to the map data.

Next, the oil deterioration degree derivation function will be described with reference to FIG.
FIG. 3 shows the case where the oil consumption (the amount of decrease in the remaining amount of engine oil O, specifically, the amount obtained by subtracting the current remaining oil amount from the remaining oil amount at the previous replacement) is large and small. It represents the change over time in the degree of oil deterioration. That is, the degree of deterioration of the engine oil O (acid value of the engine oil O) increases as the oil consumption increases or the accumulated oil use time (the accumulated use time of the engine oil O, specifically, the time since the last replacement). It can be seen that there is a correlation that the longer the integrated operation time of the engine 1 is, the higher it is.

  That is, the oil deterioration degree derivation function is a function in which the deterioration degree of the engine oil O increases as the oil consumption amount increases or the oil use integration time increases. In addition, the degree of deterioration of each engine oil O at a plurality of different oil consumptions and accumulated oil use times is obtained in advance through experiments, etc., and the obtained degree of deterioration of the plurality of engine oils O is calculated based on oil consumption and oil use accumulation. Map data compiled every hour may be created, and the actual oil consumption and accumulated oil use time may be applied to the map data to derive the actual degree of deterioration of the engine oil O.

  Next, a flow showing the engine oil O monitoring process of the engine system 100 will be described with reference to FIG.

  The oil temperature rise rate deriving unit 21 or the cooling water temperature rise rate deriving unit 22 determines whether or not the accumulated oil use time acquired from a timer (not shown) or the like has reached a normal oil replacement guide time. For example, when the accumulated oil use time reaches 6000 hours, which is a normal oil replacement guide time, the process proceeds to Steps # 102 and # 105 described later (Step # 101).

Next, the cooling water temperature rise speed deriving means 22 receives a signal indicating that the engine 1 has started operation from the engine operation control means 23, and at the time of receiving the signal, the engine 1 is in a cold state. If it is determined that there is, the cooling water temperature is acquired multiple times per unit time from the cooling water temperature sensor 12 during the start-up operation from the time of the cold state to the time when a predetermined time has elapsed (step # 102). .
Whether or not the engine 1 is in the cold state is determined, for example, by whether or not the temperature difference between the cooling water temperature detected by the cooling water temperature sensor 12 or the outside air temperature is equal to or less than a set value. Can be done. Further, the set value may be a constant value, but for example, a different value may be set for each season. As another method, the coolant temperature at the start of one or more start operations in the past is stored, and the coolant temperature at the start of this start operation is stored in the past coolant water. If the temperature is relatively low on the basis of the average value of the temperature or the like, it can be determined that the state is cold.

  The cooling water temperature rise speed deriving means 22 derives the cooling water temperature rise speed based on the cooling water temperature acquired during the start-up operation (step # 103). The rate of increase in the cooling water temperature is, for example, the time taken for the cooling water temperature to rise to a set temperature (for example, 70 ° C. or the cooling water temperature + 40 ° C. at the start of the start-up operation) It can be determined as an average value or maximum value of the rate of increase in cooling water temperature up to temperature (° C./min).

  The reference value determining unit 32 determines the oil state reference value from the rising speed of the cooling water temperature (step # 104).

  On the other hand, simultaneously with the derivation processing of the cooling water temperature rise speed in the above-described step # 102 to step # 103, the oil temperature rise speed derivation means 21 is the time when the engine 1 starts operation from the engine operation control means 23. When it is determined that the engine 1 is in the cold state at the time when the signal is received, the oil temperature sensor 11 is activated during the start-up operation until a certain time has elapsed from the cold state. To obtain the oil temperature a plurality of times per unit time (step # 105).

  The oil temperature increase speed deriving means 21 derives the oil temperature increase speed based on the oil temperature acquired during the start-up operation (step # 106). The rate of increase in the oil temperature is, for example, the time it takes for the oil temperature to rise to a set temperature (for example, 70 ° C. or the oil temperature at the start of start-up operation + 40 ° C.) It can be determined as the average value or maximum value of the rate of increase in oil temperature (° C./min).

  Further, the oil temperature rising speed deriving means 21 estimates the remaining amount of engine oil O from the oil state reference value and the rising speed of the oil temperature according to the remaining oil amount deriving function. (Step # 107).

  The oil deterioration degree estimation unit 33 estimates the deterioration degree of the engine oil O from the estimated value of the remaining amount of engine oil and the accumulated oil use time according to the oil deterioration degree derivation function (step # 108).

  The notification unit 24 acquires the remaining amount of the engine oil O in the oil state and the estimation result of the deterioration level of the engine oil O from the oil deterioration level estimation unit 33 and notifies the user of the estimation result. The notification means 24 is an external device when the estimation result of the remaining amount of the engine oil O is less than a preset lower limit value, or when the deterioration level of the engine oil O is higher than the upper limit value of the engine oil O. Audio output and display output for a certain speaker 51 and display 52 such as “It is almost time to check”, “It is now time to check” or “The engine has been stopped because it has passed the check time” (Step # 109).

The engine operation control means 23 acquires the oil state that is the estimation result of the remaining amount of the engine oil O and the deterioration degree of the engine oil O from the oil deterioration degree estimating unit 33, and the estimation result of the remaining amount of the engine oil O is set in advance. When the engine lower limit value is smaller than the upper limit value of the engine oil O or the estimated result of the deterioration degree of the engine oil is higher than the upper limit value of the engine oil O, the spark plug 2 provided in the engine 1 is stopped and the engine 1 is operated. Is stopped (step # 110).
The processes from step # 102 to step # 110 are set to be repeatedly executed.

[Another embodiment]
(1) In the above-described embodiment, the oil state estimation unit 30 may not include the oil remaining amount estimation unit 31 separately. In other words, the oil deterioration degree estimation unit 33 can be configured to receive the rising speed of the oil temperature and the oil state reference value and directly estimate the deterioration degree of the engine oil O. In this case, the oil deterioration degree estimation unit 33 estimates the deterioration degree of the engine oil O based on the degree of change in the rising speed of the oil temperature. The change rate of the oil temperature rise rate is, for example, the change rate from the oil temperature rise rate when the oil use accumulated time is short to the oil temperature rise rate when the oil use accumulated time is long. The degree of deterioration of oil is represented by a function that increases as the degree of change increases.

(2) In the embodiment described above, the oil state has been described as the remaining amount of engine oil O and the degree of deterioration of engine oil O. However, the oil state may be either the remaining amount of engine oil O or the degree of deterioration of engine oil O. May be.

(3) In the above-described embodiment, the oil state reference value is determined based on the rising speed of the cooling water temperature, but may be determined based on the environmental temperature. That is, as shown by a two-dot chain line in FIG. 1, an internal temperature sensor 13 that functions as an environmental temperature measuring means for measuring the internal temperature of the casing 7 is provided inside the casing 7 described above. The reference value determination unit 32 can determine, for example, the internal temperature measured by the internal temperature sensor 13 at the start of the warm-up operation as the environmental temperature of the engine 1 and determine the oil state reference value according to the environmental temperature. In addition, not the internal temperature but the temperature of the engine cooling water or the exhaust gas temperature at the start of the warm-up operation may be the environmental temperature, and the external temperature of the casing 7 may be the environmental temperature.
In this case, the following processing is executed instead of the processing from step # 102 to step # 105 in the flow of FIG. 4 showing the above-described monitoring processing of the engine oil O of the present invention.
When the reference value determination unit 32 receives a signal indicating that the engine 1 has started operation from the engine operation control unit 23, the reference value determination unit 32 acquires the environmental temperature at that time. Then, the reference value determination unit 32 determines an oil state reference value serving as a reference for the rising speed of the oil temperature for estimating the remaining amount of the engine oil O based on the acquired environmental temperature. At this time, since the rising speed of the oil temperature increases due to the increase in the environmental temperature, the higher the environmental temperature, the faster the oil state reference value is determined.

  The oil condition monitoring apparatus according to the present invention enables the engine oil O to be replaced at an appropriate time with a simple configuration without providing the engine oil O level sensor and operates the engine in an appropriate engine oil O condition. As an oil condition monitoring device that can

Block diagram showing the overall configuration of an engine system equipped with an engine oil condition monitoring device A graph showing the correlation between the remaining amount of engine oil, the rising speed of the oil temperature, and the rising speed of the coolant temperature Graph showing the correlation between the degree of deterioration of engine oil (acid value of engine oil), oil consumption and accumulated oil use time The flowchart which shows the monitoring process of the engine oil of this invention

Explanation of symbols

1: Engine 11: Oil temperature sensor (oil temperature measuring means)
12: Cooling water temperature sensor (cooling water temperature measuring means)
13: Internal temperature sensor (environmental temperature measurement means)
21: Oil temperature rising speed deriving means 22: Cooling water temperature rising speed deriving means 30: Oil state estimating means 23: Engine operation control means 24: Notification means O: Engine oil JW: Cooling water

Claims (9)

An engine oil condition monitoring device for monitoring an engine oil condition of an engine,
Oil temperature measuring means for measuring the oil temperature which is the temperature of the engine oil;
Oil temperature increase rate deriving means for deriving the oil temperature increase rate based on the measurement result of the oil temperature measurement means during the warm-up operation of the engine;
An engine oil state monitoring device comprising oil state estimating means for estimating an oil state corresponding to the remaining amount of engine oil from the oil temperature rising speed derived by the oil temperature rising speed deriving means.   The engine oil state monitoring device according to claim 1, wherein the oil state estimation unit determines an oil state reference value that serves as a reference for estimating the oil state based on a temperature state of the engine. A cooling water temperature measuring means for measuring a cooling water temperature which is a temperature of the cooling water of the engine;
A cooling water temperature rise rate deriving unit for deriving an increase rate of the cooling water temperature as a temperature state of the engine based on a measurement result of the cooling water temperature measurement unit during the warm-up operation,
The engine oil state monitoring device according to claim 2, wherein the oil state estimation means determines the oil state reference value based on the cooling water temperature rising speed derived by the cooling water temperature rising speed deriving means. Either the temperature inside or outside the casing of the engine during the warm-up operation, the coolant temperature that is the temperature of the engine coolant during the warm-up operation, or the exhaust gas temperature of the engine during the warm-up operation Environmental temperature measuring means for measuring an environmental temperature as one of the temperature states of the engine ,
The engine oil state monitoring apparatus according to claim 2, wherein the oil state estimation unit determines the oil state reference value based on the environmental temperature measured by the environmental temperature measurement unit. As the measurement result of the oil temperature measuring means at the time of the warm-up operation, either claim 1 using a measurement result of the oil temperature measuring means during operation of transition from the cold state of the engine in hot state of 4 The engine oil condition monitoring device according to claim 1.   6. The oil state estimation unit estimates the remaining amount of the engine oil as the oil state using a correlation between the rising speed of the oil temperature and the remaining amount of the engine oil. The engine oil condition monitoring apparatus according to one item.   The oil state estimation means estimates the degree of deterioration of the engine oil as the oil state using a correlation among the remaining amount of engine oil, the accumulated usage time, and the degree of deterioration. The engine oil condition monitoring apparatus according to one item.   The engine oil state monitoring apparatus according to any one of claims 1 to 7, further comprising a notification unit that performs a notification process for a user according to an estimation result of the oil state estimation unit.   The engine oil state monitoring apparatus according to any one of claims 1 to 8, further comprising an engine operation control unit that determines whether or not the engine can be operated according to an estimation result of the oil state estimation unit.

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