KR20220014518A - Apparatus for monitoring oil oxidation in real time - Google Patents

Abstract

The present invention relates to an engine oil oxidation degree measurement apparatus and, more specifically, to an engine oil oxidation degree measurement apparatus which can measure an accurate oil oxidation degree by compensating for light output changes in accordance with the temperature of engine oil and ambient temperature. To achieve the objective, according to the present invention, the engine oil oxidation degree measurement apparatus comprises: a light source emitting light to engine oil; a photodetector detecting a light signal outputted from the light source and received through engine oil; and a calculation unit calculating the oxidation degree of engine oil from a light signal detected by the photodetector. The engine oil oxidation degree measurement apparatus further comprises a temperature sensor unit measuring the temperature of engine oil or around an engine. The calculation unit compensates for light signal changes detected by the photodetector in accordance with temperature changes detected by the temperature sensor unit to calculate the oxidation degree of engine oil.

Description

Engine oil oxidation degree measuring device {APPARATUS FOR MONITORING OIL OXIDATION IN REAL TIME}

The present invention relates to a device for measuring the degree of oxidation of engine oil, and more particularly, to an device for measuring the degree of oxidation of engine oil capable of measuring the degree of oxidation of oil more accurately by correcting a change in light output according to the temperature of engine oil and ambient temperature will be.

In general, the condition of oil has important information on the performance and condition of the target machine, and an important point in using the oil is when to change the engine oil. In the case of automobiles, it is common that most of the oil change is performed based on the period of use recommended by the vehicle manufacturer. However, since the lifespan of oil can vary greatly depending on various factors such as oil quality, engine type, vehicle driving conditions, and environmental conditions, it is difficult to apply only a simple arithmetic average standard.

The technical reason that the oil can no longer be used is the physical/chemical contamination of the oil. First, physical contamination is caused by wear particles due to wear of mechanical system components using oil and dust particles mixed from outside. As such, the oil-contaminated particles not only induce damage by grinding the surface of machine elements such as bearings or gears, but also cause damage to the machine surface again by the wear particles due to grinding. Next, chemical contamination is mainly caused by the mixing of moisture or oil degradation products, coolant or other types of lubricants.

Pollution degree measurement and viscosity measurement methods used to measure changes in the physical state of oil can grasp information about physical changes such as the presence of metal wear particles or increase in viscosity, but loss of additives or other changes in the chemical function of In many cases, it is very useful to understand the chemical change of oil that occurs in the process of oil deterioration, and through the measurement, the state of the target machine can be more accurately diagnosed.

Automotive oil is not only continuously subjected to a high temperature atmosphere, but is also oxidized and deteriorated by contact with nitrogen oxide gas, moisture, and air. Along with this, the additives are also consumed or damaged. Accordingly, various types of oil deterioration products and contaminants are accumulated in the oil over time.

In particular, when the antioxidant additive component is consumed, the oxidation of the oil occurs significantly. Accordingly, the viscosity of the oil increases and a sticking material is formed, and the acid products corrode the machine element parts, resulting in a dark color, a strong odor, and an increase in acid value.

As a method for quantitatively measuring such changes in oil, the method for measuring the total acid value described in the American standard (ASTM) D664, the method for measuring the total alkalinity (ASTM D4739), the method for measuring the kinematic viscosity (ASTM D445/446), the diesel engine oil Standard measurement methods such as fuel oil dilution measurement method (ASTM D3524-90), volatilization point measurement method (ASTM D92), and oxidation degree measurement method (ASTM D2272) are used. However, this laboratory measurement operation samples the oil to be analyzed from the target mechanical system, and requires an appropriate pretreatment process prior to its analysis, requiring a lot of analysis time and cost. In particular, a problem may arise in which it is not certain whether or not the sample oil is well representative of the oil condition of the entire machine. Therefore, application of a measuring device capable of diagnosing the state of oil in real time without the need for oil sampling operation is essential.

General oil analysis includes various physical properties such as oil viscosity, insulation rate, AC conductivity, resistance and impedance, corrosion, pH value, total alkalinity, acid content, spectroscopic analysis, and optical density. /Based on chemical characterization.

Among these analysis methods, a method of measuring the oil state in real time by irradiating light to engine oil and analyzing the received light, such as infrared spectroscopy or fluorescence analysis, has been studied a lot in recent years. Korean Utility Model Publication No. 20-1998-0050251 (Engine Oil Deterioration Detection Device, October 7, 1998), Korean Utility Model No. 20-1999-0011486 (Engine Oil Viscosity Measurement Device, March 25, 1999), Republic of Korea Patent Registration 10-0427870 (Engine oil inspection device using infrared spectrometer, 2004.04.08), Republic of Korea Patent No. 10-0504310 (Oil oxidation measuring device using ultraviolet fluorescence characteristics, 2005.07.20), Republic of Korea Patent No. 10-0789724 (Method and Apparatus for Real-Time Monitoring of Oil Oxidation by Fluorescence Measurement, Dec. 21, 2007), Korean Patent Registration No. 10-1356176 (Method and System for Detecting Engine Oil Deterioration, Jan. 20, 2014), Korean Patent Registration No. No. 10-1566499 (Method for measuring the degree of deterioration of engine oil for a vehicle and a method for determining engine oil replacement timing using the method, November 10, 2015) and Korean Patent Laid-Open No. 10-2018-0104019 (Oil using fluorescence rise-time Deterioration Determination, 2018.09.19) discloses various techniques for monitoring the degree of oxidation of engine oil by irradiating light to engine oil and detecting the transmitted light, scattered light, or fluorescence as described above.

However, the light-emitting and light-receiving elements commonly used in the prior art have a high sensitivity to temperature, so that an output change according to a temperature deviation occurs, so that the precision of the measured oil oxidation degree is deteriorated.

In particular, in the case of automobiles, not only the engine room temperature difference is significant between winter and summer, but also the engine temperature before and after operation is large. This leads to a change in output and consequently an error in the measurement of oil oxidation.

Republic of Korea Public Utility Model No. 20-1998-0050251 (October 7, 1998): Engine oil deterioration detection device Republic of Korea Public Utility Model No. 20-1999-0011486 (Mar. 25, 1999): Viscosity measuring device for engine oil Republic of Korea Patent No. 10-0427870 (April 2004.04.08): Engine oil inspection device using infrared spectrometer Republic of Korea Patent No. 10-0504310 (July 20, 2005) Oil oxidation measuring device using ultraviolet fluorescence characteristics Republic of Korea Patent No. 10-0789724 (2007.12.21): Real-time monitoring method and apparatus for oil oxidation by fluorescent light measurement Republic of Korea Patent Registration No. 10-1356176 (Jan. 20, 2014): Engine oil deterioration detection method and system Republic of Korea Patent Registration No. 10-1566499 (November 10, 2015): A method for measuring the degree of deterioration of engine oil for a vehicle and a method for determining an engine oil replacement time using the method Korean Patent Laid-Open Patent No. 10-2018-0104019 (2018.09.19): Determination of oil deterioration using fluorescence rise-time

The present invention has been devised in recognition of the above points, and it is to provide an engine oil oxidation degree measuring device capable of measuring the degree of oxidation of oil more accurately by correcting the change in light output according to the temperature of the engine oil and the ambient temperature. .

In order to achieve the above object, an engine oil oxidation measuring apparatus according to the present invention includes a light source for irradiating light with engine oil, a photodetector for detecting an optical signal output from the light source and received through engine oil; In the engine oil oxidation degree measuring device configured to include a calculator for calculating the degree of oxidation of the engine oil from the optical signal detected by the photodetector, the device further includes a temperature sensor section for measuring the temperature of the engine oil or the engine surroundings, the calculation The unit is characterized in that the oxidation degree of the engine oil is calculated by correcting a change in the optical signal detected by the photodetector according to the change in temperature measured by the temperature sensor unit.

In addition, in the engine oil oxidation measuring apparatus according to the present invention, the calculator calculates the temperature-optical signal relationship from the temperature measured by the temperature sensor and the data obtained by measuring the optical signal detected by the photodetector at the temperature. is recorded, and the calculator corrects the optical signal measured in real time using the recorded temperature-optical signal relationship.

In addition, in the engine oil oxidation measuring device according to the present invention, the calculation unit continuously or constant time interval between the temperature measured by the temperature sensor unit and the optical signal detected by the photodetector from the initial start to a state in which the engine temperature is normalized. It is characterized in that the temperature-light signal relationship is calculated by measuring with

With the above configuration, the apparatus for measuring the degree of oxidation of engine oil according to the present invention has the advantage of being able to measure the degree of oxidation of oil more accurately by correcting the change in light output according to the temperature of the engine oil and the ambient temperature.

1 is a block diagram showing the configuration of an engine oil oxidation degree measuring apparatus according to an embodiment of the present invention;
2 is a flowchart illustrating a process in which temperature correction is performed by an engine oil oxidation measurement apparatus according to an embodiment of the present invention;

Hereinafter, an engine oil oxidation measuring apparatus according to the present invention will be described in more detail with reference to the drawings and examples.

1 is a block diagram illustrating the configuration of an engine oil oxidation degree measuring device according to an embodiment of the present invention, and FIG. 2 is a process of temperature correction by the engine oil oxidation degree measuring device according to an embodiment of the present invention. is a flowchart showing

Referring to FIG. 1 schematically showing an engine oil oxidation degree measuring apparatus according to an embodiment of the present invention, the engine oil oxidation degree measuring apparatus according to an embodiment of the present invention includes a light source 11 and a photodetector 12 . , the temperature sensor units 21 and 22 , the calculation unit 30 , and the storage unit 40 are provided and configured.

The light sources 11 are each configured to irradiate light to the engine oil O, and the photodetector 12 is configured to detect an optical signal output from the light source 11 and received through the engine oil. .

The light source 11 and the photodetector 12 may be mounted on a portion of the engine E containing engine oil O, such as an oil fan. In addition, the light source and the photodetector may be mounted on the oil circulation line (L) through which the engine oil (O) is circulated. 1, the light source 11' and the photodetector 12' mounted on the oil circulation line L together with the light source 11 and the photodetector 12 mounted on the oil pan of the engine E are simultaneously shown. However, it can consist of only one by selecting one of them.

The optical signals output from the light sources 11 and 11' and received by the photodetectors 12 and 12' through the engine oil O vary depending on the state of the engine oil O. At this time, various optical signals and optical signals Analytical techniques may be used.

For example, when a fluorescence signal of engine oil O is used, a laser diode emitting 450 nm laser light is applied to the light sources 11 and 11', and the photodetectors 12 and 12' are the light sources. In (11, 11'), the fluorescence signal in the 530 to 580 nm band generated by the aromatic hydrocarbon-based, polyphenyl hydrocarbon, and carboxyl compound of the engine oil (O) is detected with respect to the laser light irradiated with the engine oil (O). , a signal corresponding to the detected light intensity is output to the calculator 30 . As the engine oil O is oxidized, the fluorescence signal in the 530 to 580 nm band is gradually attenuated, and the present invention may be configured to calculate the oxidation degree from the attenuation of the fluorescence signal.

The temperature sensor units 21 and 22 are configured to measure engine oil or a temperature around the engine. In the drawing, a temperature sensor unit 21 that is mounted on an oil fan containing engine oil O to measure the temperature of engine oil O, and an engine room that measure the temperature around the engine E An embodiment in which a temperature sensor unit 22 is provided is shown. Accordingly, according to the present invention, the temperature around the engine or the temperature of the engine oil can be simultaneously used or one can be selected and used depending on whether the engine E is being operated.

The calculator 30 calculates the degree of oxidation of the engine oil from the optical signals detected by the photodetectors 12 and 12'. In particular, in the engine oil oxidation measurement apparatus according to the present invention, the light detected by the photodetectors 12 and 12' according to the change in the temperature measured by the temperature sensor units 21 and 22 by the calculator 30 . It is characterized in that it is configured to calculate the oxidation degree of the engine oil (O) by correcting the change in the signal.

First, an example of calculating the degree of oxidation of engine oil using the fluorescence signals detected by the photodetectors 12 and 12' will be described. The calculator 30 measures the fluorescence signal generated from the newly replaced new oil when the new engine oil is introduced into the engine E to replace it, sets it as a reference signal and stores it in the storage unit 40 . Then, the calculator 30 measures the fluorescence signal changed according to the oxidation of the engine oil (O) according to the use of the engine oil (O) after the replacement of the new oil and compares it with the reference signal to determine the level of the engine oil (O) yields the degree of oxidation. According to the above, if the oxidation degree calculated by the calculator 30 corresponds to the preset oil replacement reference condition and requires replacement, it is displayed on a lamp or a display screen so that the user can know this.

On the other hand, since a light-emitting element such as a laser diode used as the light source or a light-receiving element such as a photosensor used in the photodetector has high sensitivity to temperature, a change in output according to temperature deviation occurs, so that the photodetector 12, The optical signal detected at 12') has an error according to the temperature. In the present invention, the light detected by the photodetectors 12 and 12' reflects the temperature change measured by the temperature sensor units 21 and 22. It is characterized in that it is configured to calculate the oxidation degree of the engine oil more accurately by correcting the signal change.

Referring to FIG. 2 showing a process for such temperature correction, the engine oil oxidation measuring apparatus according to an embodiment of the present invention calculates the temperature-optical signal relationship in advance in a mode for calculating the temperature-optical signal relationship, and , using the temperature-light signal relationship to calculate the oil oxidation degree in real time in the oil oxidation degree real-time measurement mode to determine whether the oil needs to be replaced.

In the mode for calculating the temperature-optical signal relationship, the calculation unit 30 calculates the temperature measured by the temperature sensor units 21 and 22 and the optical signal detected by the photodetectors 12 and 12' at the temperature. From the measured temperature and optical signal data, the temperature-optical signal relationship is calculated and recorded.

For example, when the operation of the engine is started in the mode for calculating the temperature-light signal relationship, the optical signals detected by the photodetectors 12 and 12' and the corresponding temperature sensors 21 and 22 are measured. Data on the set temperature is stored in the storage unit (40). The calculator 30 calculates the temperature-optical signal relationship by using the data about the temperature and the optical signal stored in the storage 40 . On the other hand, when the operation of the engine continues to some extent, a steady state in which the temperature of the engine oil hardly changes is reached. In the present invention, the temperature measured by the temperature sensor units 21 and 22 is It is configured to measure the temperature and the optical signal detected by the photodetectors 12 and 12' continuously or at regular time intervals (periodically) to calculate the temperature-optical signal relationship.

Calculation of the above-described temperature-light signal relationship is preferably performed when new oil is replaced, and this calculation may be performed not only once, but also may be performed multiple times and calculated through statistical processing.

In the oil oxidation degree real-time measurement mode, the optical signal measured in real time is corrected using the temperature-optical signal relationship calculated and recorded in the mode for calculating the temperature-optical signal relationship, and the corrected optical signal is used. yields the degree of oxidation. As described above, in the oil oxidation level real-time measurement mode, an optical signal such as a fluorescence signal changed according to the oxidation of engine oil (O) according to the use of engine oil (O) after new oil is measured and compared with a reference signal. The oxidation degree of engine oil (O) is calculated, and when the calculated oxidation degree corresponds to a preset oil replacement reference condition and replacement is required, this is displayed on a lamp or a display screen.

The engine oil oxidation degree measuring apparatus described above and shown in the drawings is only one embodiment for carrying out the present invention, and should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is defined only by the matters described in the claims below, and improved and changed embodiments without departing from the gist of the present invention are obvious to those of ordinary skill in the art to which the present invention belongs. It will be said that it falls within the protection scope of the present invention.

E engine
O engine oil
P oil circulation pump
L oil circulation line
11,12 Light source and photodetector
21,22 temperature sensor unit
30 output
40 storage

Claims (1)

A light source for irradiating light with engine oil, a photodetector for detecting an optical signal output from the light source and received through the engine oil, and a calculation unit for calculating the degree of oxidation of engine oil from the optical signal detected by the photodetector In the engine oil oxidation degree measuring device configured as
A temperature sensor unit for measuring the engine oil or temperature around the engine is further included,
and the calculator calculates the degree of oxidation of the engine oil by correcting the change in the optical signal detected by the photodetector according to the change in temperature measured by the temperature sensor.

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