JP2002250213A - Apparatus for determining oil exchange timing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more directly and inexpensively detect degradation of oil compared with conventional technique, in a determination apparatus of oil exchange timing based on an operating state of an engine. SOLUTION: When it is detected that the engine is operated only for keeping an idling state, a fuel injection amount of the engine per unit time is calculated, and the determination is made to be the timing of oil exchange based on a relation between the fuel injection amount at present and the fuel injection amount at a time to exchange the oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil change timing judging device, and more particularly to an oil judging time judging device for judging an engine lubricating oil change timing based on an operating state of an engine.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for determining an oil change timing based on an operating state of an engine, a travel distance of a vehicle or an engine driving time is integrated, and this integrated value is compared with a previously set value. JP-A-10-38605 discloses a vehicle maintenance time alarm device that determines the oil change time by doing so.

[0003]

In the prior art in which the oil change timing is determined based on the mileage and the engine driving time as described above, the deterioration of the oil is indirectly determined. Often, oil is changed early, and parts that can still be used are often replaced.

On the other hand, Japanese Patent Application Laid-Open Nos. 2000-130240 and 8-622 disclose an apparatus for judging oil deterioration using a sensor.
There are JP-A-07-1995, JP-A-9-100712, and JP-A-11-270787, but there is a problem that the determination of the oil replacement time by the sensor increases the component cost.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an apparatus for judging oil replacement timing based on the operating state of an engine so that deterioration of oil can be detected more directly and the replacement timing can be determined at low cost. And

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an oil change timing judging device according to the present invention comprises a detecting means for detecting that an engine is used only in an idling operation state, and an idling operation state. Calculating means for calculating a fuel injection amount per unit time of the engine, and judging means for judging oil replacement time when the current fuel injection amount increases by more than a specified value from the fuel injection amount at the time of oil replacement. , Is provided.

The fuel consumed during idling is consumed to overcome the friction loss and maintain the rotation. Friction loss in crankshafts and pistons accounts for about 50% in gasoline engines and about 30-40% in diesel engines.
As the oil deteriorates, the friction loss of the crankshaft and the piston increases, and the fuel consumed during idling increases.

Therefore, by recording the fuel injection amount per unit time during idling as time-dependent data, when the fuel injection amount exceeds a specified value from the time of oil change, the time for changing the engine lubricating oil is determined. You will be able to judge. Further, if the piston ring or the liner is damaged, the fuel consumed at idling increases.

Therefore, if the corrected normalized fuel consumption during idling does not return to the value as in a new vehicle after an oil change, it is possible that the piston ring and the liner are damaged. If the piston ring or liner has not been replaced for a long time, it can be determined that it is time to replace those parts.

Therefore, in the present invention, the detecting means comprises:
It detects whether the engine is in an idling operation state. In this case, it is assumed that the engine is used only for idling operation. When such a state of only the idling operation is detected, the calculating means calculates the fuel injection amount per unit time of the engine. Then, the determination means compares the current value of the fuel injection amount with the value at the time of oil change, and determines that it is time to change the oil when it is found that the former has increased by more than the specified value compared to the latter.

Thus, the oil change timing is determined without using a sensor or the like, and based on the fuel injection amount, which is a more direct parameter than the indirect oil deterioration parameters such as the mileage and the engine drive time. Therefore, the deterioration state of the oil can be detected more accurately and inexpensively, and it is possible to prompt an appropriate oil change.

The above-mentioned calculating means calculates the fuel injection amount as
A value obtained by correcting the multiplication value of the target fuel injection amount and the engine speed by the oil viscosity temperature characteristic or the engine temperature characteristic can be used. In other words, oil has different temperature characteristics of viscosity depending on the type.
The fuel consumption during idling is corrected and normalized based on the viscosity data corresponding to the type of the oil and the oil temperature.
Alternatively, the fuel consumption during idling may be corrected and normalized based on the engine cooling water temperature.

The above-mentioned idling operation state is preferably an idling operation state after the oil temperature is stabilized. In addition, the above-mentioned determination means corrects the engine speed per unit time, which drops during the fuel-free injection period after the fuel is removed, by using the temperature characteristic of the oil viscosity or the engine temperature characteristic, and this correction value is used as the correction value. It can also be used to determine the oil change time.

That is, as a method for determining the engine friction loss, as described above, after the temperature of the engine lubricating oil is stabilized and the fuel consumption during idling is measured, the engine is emptied and the fuel injection amount is immediately measured. From the time when is set to zero to the time when re-injection starts near idle rotation Δ
the rate of decrease ΔN /
A value obtained by correcting Δt based on the temperature of the engine lubricating oil is used as time-dependent data.

In this case, when the friction loss of the engine increases due to deterioration of the oil and the like, the value corrected and normalized with the oil temperature of ΔN / Δt becomes larger than that in the case where there is no oil deterioration and the like. The determining means may further add to the determination of the oil change timing on the condition that the traveling distance or the total engine speed exceeds a threshold.

[0016]

FIG. 1 shows an embodiment of an oil change timing judging device according to the present invention. A master controller 1, an engine control device 2, an air conditioner control device 3, and an alarm device (voice) 4 The fuel injection amount measurement instructing device 5 and the fuel injection amount measurement instructing device 5 are connected to each other via a common bus 6 to form an in-vehicle serial communication network. The service tool 7 is directly connected to the master controller 1.

The master controller 1 is an arithmetic unit for executing the processing program shown in FIG.
Are vehicle speed V, accelerator opening A, engine speed Ne, engine coolant temperature Tw, clutch signal CS, and neutral signal
NS is input from each sensor (not shown), and the target fuel injection amount Qfin is calculated and output as needed.

The air conditioner control device 3 determines whether the air temperature Ta
Is input from a sensor (not shown), and a compressor control signal CMP is output. The alarm device 4 receives the write signal LS, the PTO activation signal PS, the cab tilt signal CT, and the dump / wing signal DW and transfers them to the master controller 1 as appropriate.

The fuel injection amount measurement instructing device 5 receives a fuel injection amount (Qn) measurement instruction signal D1 and a clutch operation instruction signal D1 under the control of the master controller 1 as described later.
2, and an oil deterioration display signal D3.
The service tool 7 initializes the data of the master controller 1, down / up / loads, registers the oil type, and performs other operations such as the fuel injection amount immediately after the oil change and the fuel injection amount at the final measurement. It displays data and displays the mileage at the time of the final measurement, etc.
In addition, a temporary measurement request can be given to the master controller 1.

Hereinafter, the master controller 1 will be described with reference to FIG.
Will be described. It is assumed that the service controller 7 has initialized the constant data of the master controller 1 as appropriate. First, master controller 1
After the oil temperature is stabilized for a certain period (t1), it is determined whether or not the engine is being used only in the idling state (step S1).

This is because when the engine is idling at the time when the oil temperature is stabilized when the vehicle is new or when the oil is replaced with a new one, the fuel consumption consumed due to wear loss of the engine alone is accurately recorded. It is determined whether or not it is possible to do so, so as not to be affected by friction loss of other devices.

Therefore, it is necessary to satisfy the following conditions (1) to (10). (1) Accelerator opening during t1 seconds: 0% That is, the master controller 1 inputs the accelerator opening A via the engine control device 2, and the accelerator opening A indicates 0% during t1 seconds, Make sure the pedal is not depressed.

(2) Current engine cooling water temperature Tw: 75 to 90 ° C. That is, the master controller 1 inputs the engine cooling water temperature Tw through the engine control device 2, and the current value of the engine cooling water temperature Tw is 75 Since it is ~ 90 ° C, make sure that the engine is warmed up.

(3) Engine cooling water temperature t1 seconds before: Tw ± ΔT
Within ° C. That is, since the engine cooling water temperature Tw before t1 second is within ± ΔT ° C., it is determined that the engine cooling water temperature is stable, and it is estimated that the temperature of the engine lubricating oil is also stable. If the engine oil temperature can be directly input to the master controller 1 as shown in the figure, the time t1 can be reduced.

(4) Current engine speed Ne: within ± ΔN (rpm) of the specified idling speed. That is, the master controller 1 inputs the engine speed Ne via the engine control device 2 to obtain the current engine speed. Number Ne is ± ΔN of specified idling speed
(rpm).

(5) Vehicle speed V: 0 km / h That is, the master controller 1 inputs the vehicle speed V via the engine control device 2 and confirms that the vehicle speed V is 0 km / h (stopped). (6) Air conditioner: non-operation In other words, when the air conditioner controller 3 outputs a compressor control signal CMP to an air conditioner compressor (not shown) based on the atmospheric temperature Ta, the master controller 1 If is not operating, make sure that no fuel has been consumed to run the compressor.

(7) PTO: Non-operation In other words, the master controller 1 sends the PTO
When the activation signal PS is input and the PTO activation signal PS indicates that the PTO is not activated, it is confirmed that fuel is not consumed for driving the PTO.

(8) Cab tilt: non-operation In other words, the master controller 1 also inputs the cab tilt signal CT from the alarm device 4 and when the cab tilt signal CT indicates that the cab tilt is not operating.
Ensure that no fuel is consumed for power generation via the ACG (generator).

(9) Cargo wing: non-operation In other words, dumping and dumping are performed in the same manner as in (8) above.
Confirm that fuel is not consumed for power generation based on the wing signal DW. (10) Light: OFF That is, it is confirmed that the light is not turned on by the write signal LS.

When the above conditions (1) to (10) are satisfied,
The master controller 1 releases the clutch (step S
2) is output as a clutch operation instruction signal D2 via the fuel injection amount measurement instruction device 5. This is performed to eliminate the fuel consumption due to the wear loss of the transmission portion, and is not executed in the case of an automatic transmission without a clutch, and is skipped.

Thereafter, the operation waits for t2 seconds until the clutch is disconnected. This is provided with a standby time in order to eliminate the effects of the half-clutch state and the response delay in the fuel injection control of the engine control device 2. This step is also performed only in a manual vehicle. Thereafter, the master controller 1 determines the average value Qn of the fuel injection amount Q per unit time in the t3 period.
Is calculated (step S4).

FIG. 3 shows the calculation process of the fuel injection amount Qn in more detail. The target fuel injection amount Qfin indicates a target value of the fuel that the engine control device 2 is about to inject at that time, and indicates a volume of fuel injected in one stroke per cylinder of the engine. Therefore, a value obtained by multiplying the target fuel injection amount Qfin by the engine speed Ne is a value proportional to the fuel injection amount Q per unit time.

Here, in the control of fuel injection during idling, when the target idling rotational speed N ₀ is set and the current engine rotational speed is Ne, the value of ΔNe = Ne−N ₀ is positive. , The target fuel injection amount is proportional to the value of ΔNe
If the value of Qfin is decreased and ΔNe is negative, proportional control is generally performed to increase the target fuel injection amount Qfin in proportion to the value of ΔNe.

Therefore, a value Qfin × Ne obtained by multiplying the current target fuel injection amount Qfin and the engine speed Ne is represented by the target fuel injection amount Qfin.
This is a preferable value with less fluctuation than the value of Qfin alone. Figure
Reference numeral 4 denotes an engine which is set so as to constantly control the target idling rotational speed N ₀ to 450 rpm. The fuel injection amount Q per unit time during engine warm-up (during oil temperature rise).
2 shows data obtained by actually measuring a value Qfin × Ne proportional to.

From this graph, the warm-up of the engine progresses,
It can be seen that as the oil temperature increases over time, the viscosity of the oil decreases and the fuel consumption required to maintain the same speed is reduced. Therefore, the temperature of each part of the engine lubricating oil should be measured and corrected with the temperature of the engine lubricating oil in order to normalize the fuel injection amount per unit time Q = Qfin × Ne. Since the engine temperature is deprived by the engine cooling water, it is possible to substitute and estimate the oil temperature from the engine cooling water temperature Tw.

Therefore, the engine cooling water temperature Tw is calculated based on the temperature correction map TM (see FIG. 3) provided in the master controller 1.
Is multiplied by the fuel injection amount per unit time Q = Qfin × Ne, and the temperature is corrected and normalized, and a value Qn is calculated by averaging the value measured for t3 seconds.

[0037] whether this point, the fuel injection amount Q ₀ per unit time when the oil change is by comparing the values of the fuel injection amount Qn per current unit time is greater for example, 5% or more Is determined (step S5). As a result, Qn
When it is found that> Q ₀ × 1.05, the master controller 1 outputs an oil deterioration display signal D3 via the fuel injection amount measurement instruction device 5.

In step S5, the oil deterioration is determined on the basis of the fuel injection amount for each predetermined cycle. However, when any one of the following conditions (1) to (5) is satisfied, the predetermined cycle interval is increased. Then, the determination of oil deterioration may be performed. If Qn> Q ₀ × 1.05 has never been reached, the mileage L> L1km from the previous measurement or the total engine speed Nt
> Nt1 rotation.

In the case where Qn> Q ₀ × 1.05 has been reached even once, the running distance L> L2 km or the total engine speed Nt> Nt2 rotation from the previous measurement. When the master controller 1 receives a temporary measurement request signal from the service tool 7.

The running distance L and the total engine speed Nt can both be obtained based on the engine speed Ne from the engine control device 2. Also, L2 <L1 and
If the relationship of Nt2 <Nt1 is satisfied and the degree of oil deterioration reaches 5% or more even once as shown in the above condition, the threshold value is set.
The criteria are changed by changing L1 to L2 and Nt1 to Nt2.

The above description also deals with the case where a temporary measurement request signal is received from the service tool 7 in addition to the fuel injection amount measurement interval defined inside the master controller 1. The engine oil change timing can be determined as described above. A method of measuring auxiliary data for measuring the friction loss of the engine (shown by a dotted line in FIG. 2) will be described below.

First, the engine is emptied (step S
7) After the emptying, it is determined whether or not a non-injection state has occurred within t4 seconds (step S8). If no injection occurs within t4 seconds, the process proceeds to step S9. However, if the time is longer than t4 seconds, or if the air has been emptied for more than t4 seconds, the oil temperature will rise if the air is emptied for a long time, and correct data cannot be measured. finish.

In step S9, as shown in FIG. 5, the ratio ΔN / Δt of the value ΔN at which the engine speed drops during Δt when the fuel is not injected is corrected and normalized by the engine coolant temperature Tw. Record. That is, when the engine lubricating oil deteriorates, the friction loss of the engine increases, and ΔN / Δt also increases, so that it can be used as auxiliary data for oil change timing determination.

Next, an example of using the average value Qn of the fuel injection amount Q per unit time shown in FIG. First, after the oil change, if the relationship Qn> Q ₀ × 1.05 in step S5 described above is satisfied, the data sampling interval is made smaller.

Then, under the above-mentioned additional conditions or when the traveling distance exceeds a certain distance, the master controller 1 sends the average fuel injection amount Qn via the fuel injection amount measurement instructing device 5 so as to measure the average fuel injection amount Qn. Qn measurement instruction signal D1
Is output.

As a result, the measurement interval becomes shorter, so that the driver or maintenance person can recognize that the oil change time is approaching, and can judge the oil usage limit before the engine is damaged. Becomes

[0047]

As described above, according to the oil change timing judging device according to the present invention, when it is detected that the engine is used only in the idling operation state, the fuel injection amount per unit time of the engine is detected. Is calculated, and the fuel injection amount is determined to be the oil replacement time from the relationship between the current time and the time of oil replacement.Therefore, without newly adding a sensor or using a measuring device, the traveling distance and the engine driving time are calculated. Oil replacement timing can be determined by a parameter that can more directly detect the degree of deterioration of the engine lubricating oil rather than the fuel injection amount, irrespective of indirect parameters such as, for example, so that it is more accurate and easier. Deterioration degree can be determined.

If the amount of fuel injection during idling is not improved even after replacing the oil, it can be estimated as deterioration of parts such as the piston ring, cylinder liner, and fuel injection pump.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an oil change timing determination device according to the present invention.

FIG. 2 is a flowchart showing a program of a master controller used in the oil change timing determination device according to the present invention.

FIG. 3 is a block diagram specifically showing a process of calculating an average fuel injection amount Qn calculated in the flowchart of FIG. 2;

FIG. 4 is a graph showing a fuel injection amount per unit time during engine warm-up operation in relation to an engine speed in the oil change timing determination device according to the present invention.

FIG. 5 is a graph showing a ratio of a decrease in the engine speed when the fuel is not injected in the oil change timing determination device according to the present invention.

FIG. 6 is a graph showing a situation in which an oil change timing determination device according to the present invention determines a change timing of engine lubricating oil from time-dependent data.

[Explanation of symbols]

 1 Master controller 2 Engine control device 3 Air conditioner control device 4 (sound) alarm device 5 Fuel injection amount (Qn) measurement instruction device 6 Common bus 7 Service tool

Claims (5)

[Claims] A detecting means for detecting that the engine is used only in an idling operation state; a calculating means for calculating a fuel injection amount per unit time of the engine in the idling operation state; Determining means for determining that it is time to change the oil when the injection amount increases by more than a specified value from the fuel injection amount at the time of oil change. 2. The fuel injection system according to claim 1, wherein the calculating means calculates a value obtained by correcting a multiplication value of the target fuel injection amount and the engine speed by a temperature characteristic of oil viscosity or an engine temperature characteristic as the fuel injection amount. An oil change time judging device characterized by being used. 3. The oil change timing judging device according to claim 1, wherein the idling operation state is an idling operation state after the oil temperature is stabilized. 4. The engine according to claim 3, wherein the determining means corrects the engine speed per unit time, which falls during the fuel-free injection period after the engine is idled, by a temperature characteristic of oil viscosity or an engine temperature characteristic. An oil change timing determining device, wherein the correction value is used for determining the oil change timing. 5. The method according to claim 1, wherein the determining means further adds to the determination of the oil change timing on the condition that a traveling distance or a total engine speed exceeds a threshold value. Oil change timing determination device.