JP2007064954A - Deterioration detecting method of lubricating oil and lubricating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deterioration detecting method of lubricating oil and a lubricating device capable of preventing occurrence of a failure of an internal combustion engine resulting from deterioration of the lubricating oil. <P>SOLUTION: A member 41 for measurement is arranged inside the internal combustion engine at a position where the lubricating oil dips or deposits. With deterioration of the lubricating oil, the surface 41a of the member 41 for measurement and the lubricating oil start to react with each other, and a corrosion section 71 is formed in the surface 41a. By observing the corrosion state of the corrosion section 71, the deterioration degree of the lubricating oil is detected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for detecting deterioration of lubricating oil in an internal combustion engine and a lubricating device.

  Lubricating oils used for internal combustion engines such as automobile engines are exposed to high temperatures and high pressures, and further deteriorated by mixing combustion products and the like from the outside. This deterioration of the lubricating oil increases the movement resistance of each sliding portion, resulting in a decrease in the performance of the internal combustion engine. For this reason, the lubricating oil is normally changed every time the vehicle travels a predetermined distance. However, since the deterioration of the lubricating oil is affected by the type of oil, operating conditions, operating time, etc., it often does not proceed in proportion to the distance traveled, and the lubricating oil is always replaced at an optimal time. Not necessarily.

Therefore, for the purpose of replacing the lubricating oil at an optimal time, a method for detecting the deterioration of the lubricating oil by measuring the hydrogen ion concentration in the lubricating oil has been proposed (for example, Patent Documents 1 and 2). . Such a method for detecting deterioration of lubricating oil focuses on the point that the hydrogen ion concentration increases due to oxidation of the oil itself and chemical change of additives such as antioxidants as the oil deteriorates. That is, a pH (-log [H]) sensor is provided in the lubricating oil, and the replacement of the lubricating oil is urged when the hydrogen ion concentration rises and the alkalinity (pH) falls below a predetermined value. .
Japanese Utility Model Publication No. 6-12926 JP 2004-271388 A

  By the way, in such a method for detecting deterioration of the lubricating oil, the degree of deterioration of the lubricating oil can be detected, but the degree of adverse influence on the internal combustion engine due to the use of the deteriorated lubricating oil cannot be estimated. For example, in the case where slight damage or the like has occurred in each part of the internal combustion engine due to the use of deteriorated lubricating oil, it is only necessary to measure the alkalinity in the lubricating oil and replace the lubricating oil. Can not be properly maintained. For this reason, there is a problem that it is impossible to prevent the occurrence of a malfunction of the internal combustion engine due to the deterioration of the lubricating oil, and it is impossible to extend the life of the internal combustion engine.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for detecting deterioration of a lubricating oil and a lubricating device that can prevent occurrence of a malfunction of an internal combustion engine due to deterioration of the lubricating oil. It is to provide.

  In order to achieve the above object, according to the first aspect of the present invention, a measuring member made of metal is disposed inside an internal combustion engine in which lubricating oil is immersed or struck, and the change in surface state due to corrosion of the measuring member. Is observed to detect the deterioration of the lubricating oil.

  According to this configuration, a measuring member made of a metal that comes into contact with the lubricating oil is provided inside the internal combustion engine, and the deterioration of the lubricating oil is detected by observing a state in which the measuring member reacts with the lubricating oil and corrodes. To do. Lubricating oil increases in total acid value as its deterioration progresses, and the corrosive strength of the measuring member increases, so the degree of deterioration of the lubricating oil can be detected by observing the surface condition of the measuring member due to corrosion. Can do. In addition, since the corrosion state of the measurement member is observed, it is possible to indirectly estimate the degree of adverse effects on the internal combustion engine due to the use of deteriorated lubricating oil. For this reason, since the lubricating oil can be replaced and the internal combustion engine maintenance can be performed at an appropriate time based on the observed corrosion state, the occurrence of malfunction can be prevented and the life of the internal combustion engine can be extended. Can be achieved.

  In addition, since the traces that have been corroded by the lubricating oil used in the past as well as the lubricating oil currently used are left on the measurement member, based on the observation results of these accumulated corrosion states Maintenance of the internal combustion engine can be performed.

  According to a second aspect of the present invention, in the lubricating device for supplying the lubricating oil to the sliding portion of the internal combustion engine, the lubricating oil is disposed at a position where the lubricating oil is immersed or struck, and the corrosion state changes with the deterioration of the lubricating oil. A measuring member made of a metal is provided.

  According to this configuration, the lubricating device of the internal combustion engine is provided with a measuring member made of a metal that corrodes as the lubricating oil deteriorates, so the deterioration of the lubricating oil is detected by observing the corrosion state of the measuring member. The lubricating oil can be changed at an appropriate time. Further, by observing the corrosion state of the measurement member, it is possible to estimate the history of the oil properties of the lubricating oil that has been used in the past, so that the maintenance of the internal combustion engine can be performed appropriately.

According to a third aspect of the present invention, in the lubricating device according to the second aspect, the surface of the measurement member is processed to have a mirror finish.
According to this configuration, since the surface of the measuring member is processed into a mirror finish, the change in the corrosion state of the measuring member can be accurately observed.

According to a fourth aspect of the present invention, in the lubricating device according to the second or third aspect, the measurement member is attached to a member that is detachable from the internal combustion engine.
According to this configuration, since the measurement member is attached to a member that can be attached to and detached from the internal combustion engine, the corrosion state of the measurement member can be easily observed by removing the member. As a specific example of mounting on a member detachable from the internal combustion engine as described above, as described in claim 5, the inner surface of the drain plug, the inner surface of the oil filler cap, or the tip of the oil level gauge It is possible to adopt a configuration in which a measurement member is attached to a part or the like.

According to a sixth aspect of the present invention, in the lubricating device according to the fourth or fifth aspect, the measurement member is detachably provided with respect to the detachable member.
According to this configuration, since the measurement member is detachably provided with respect to the detachable member, the measurement member can be easily replaced for each maintenance of the internal combustion engine, and the lubricating oil used thereafter The corrosion state due to can be observed with higher accuracy.

According to a seventh aspect of the present invention, in the lubricating device according to the second or third aspect, a part of the metal member that can be attached to and detached from the internal combustion engine also serves as the measurement member.
According to this configuration, since a part of the metal member that can be attached to and detached from the internal combustion engine also serves as the measurement member, it is possible to easily observe the corrosion state by making the removable metal member function as the measurement member. it can.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows a configuration of an internal combustion engine 1 provided with a lubrication device. The internal combustion engine 1 includes a cylinder block 2, a cylinder head 3 and a head cover 4 provided on the upper part of the cylinder block 2, and an oil pan 5 provided on the lower part of the cylinder block 2. A cylinder bore 11 is formed in the cylinder block 2, and a piston 12 is provided so as to be able to reciprocate. The piston 12 is connected via a connecting rod 13 to a crankshaft 14 provided at the lower part of the piston 12. The reciprocating motion of the piston 12 is converted into the rotational motion of the crankshaft 14 by the connecting rod 13. A combustion chamber 15 is formed by a space surrounded by the bottom surface of the cylinder head 3 and the upper end surface of the piston 12.

  An intake port 16 and an exhaust port 17 are formed in the cylinder head 3 so as to communicate with the combustion chamber 15. The intake port 16 and the exhaust port 17 are provided with an intake valve 18 and an exhaust valve 19, respectively. An intake camshaft 20 and an exhaust camshaft 21 for opening and closing the intake valve 18 and the exhaust valve 19 are provided on the upper side of the cylinder head 3. The intake / exhaust camshafts 20 and 21 are drivingly connected to the crankshaft 14 by a timing belt (not shown). The intake / exhaust valves 18, 19 are opened and closed by the rotation of the intake / exhaust camshafts 20, 21, thereby connecting / blocking the intake / exhaust ports 16, 17 and the combustion chamber 15. The head cover 4 is disposed so as to cover the upper side of the cylinder head 3. The oil pan 5 stores lubricating oil supplied to each lubricating part of the internal combustion engine 1.

  Next, the lubrication device provided in the internal combustion engine 1 will be described. The lubricating device includes an oil strainer 31, an oil pump 32, an oil filter 33, and an oil gallery 34. The arrows shown in FIG. 1 indicate the supply direction of the lubricating oil. The lubricating oil stored in the oil pan 5 is pumped up by the oil pump 32. The oil strainer 31 is disposed in the lubricating oil stored in the oil pan 5, removes foreign matter when the lubricating oil is sucked into the oil pump 32 from the oil pan 5, and foreign matter is not sucked into the oil pump 32. I am doing so. The oil pump 32 is driven by the rotation of the crankshaft 14 and draws lubricating oil from the oil pan 5 and supplies it to the oil filter 33. The oil filter 33 removes fine dust contained in the lubricating oil, sludge generated by the combustion of fuel, and the like. Lubricating oil purified by the oil filter 33 passes through an oil gallery 34 that is a passage of lubricating oil, and the piston 12, the connecting rod 13, the crankshaft 14 and the like in the cylinder block 2, and the intake and exhaust valves 18 in the cylinder head 3. 19 is supplied to intake / exhaust camshafts 20, 21 and the like. The lubricating oil used for the lubrication, cooling and cleaning of the above parts flows down in the cylinder head 3 and the cylinder block 2 and is stored in the oil pan 5 again.

  Next, a method for detecting deterioration of the lubricating oil will be described. When the lubricating oil is exposed to high temperature and high pressure, a part of the oil is changed to a functional group such as a —CHO group or a —COOH group by an oxidation reaction. When the oxidation further proceeds, the compound grows into a compound having a plurality of functional groups, and they are polymerized with each other. As the polymerization proceeds, the molecular weight increases, so that it becomes insoluble and starts to precipitate, and the viscosity of the oil increases. That is, when the lubricating oil is oxidized and deteriorates, the viscosity increases, which causes generation of sludge due to insoluble matter and acceleration of wear of the sliding portion. Further, since NOx contained in the exhaust gas is mixed with the blow-by gas in the lubricating oil, the oxidation of the lubricating oil by the combustion products is also promoted. Since the total acid value of the lubricating oil increases due to such oxidation, the degree of deterioration of the lubricating oil is detected by detecting an increase in the corrosive force against the metal as the total acid value increases. Hereinafter, a specific detection method will be described.

  FIG. 2 is a perspective view of a measurement member 41 provided inside the internal combustion engine for detecting the degree of deterioration of the lubricating oil. The measurement member 41 is a plate-like metal member having a thickness of about 1 mm, and the surface 41a is processed into a mirror finish in a planar shape having a rectangular shape with sides of 10 to 20 mm. The measuring member 41 is disposed at a position where the lubricating oil is immersed or struck on the surface 41a. Then, the degree of deterioration of the lubricating oil is detected by observing a state in which the surface 41a of the measuring member 41 reacts with the lubricating oil and corrodes.

  The measurement member 41 is attached to a member that can be attached to and detached from the internal combustion engine 1 in order to facilitate observation of the surface 41a. For example, the lubricating oil can be checked by attaching it to the inner surface portion 51 a of the drain plug 51 provided in the oil pan 5, the inner surface portion 52 a of the oil filler cap 52 provided in the head cover 4, or the tip portion 53 a of the oil level gauge 53. The surface 41a of the measurement member 41 can be easily observed at the time or during replacement. In addition to these places, the measurement member 41 may be attached to the service hole 54, the inner surface 55 of the head cover 4, the upper surface of the cylinder head 3, and the like.

  The measurement member 41 is fixed to each of the above members by bolting or fitting. FIG. 3A shows a state in which the measurement member 41 is fixed by the bolt 61, and FIG. 3B shows a state in which the measurement member 41 is fixed by the plurality of claw portions 62. Since the measurement member 41 is configured to be removable by fixing by bolting or fitting, the measurement member 41 can be easily exchanged for each maintenance of the internal combustion engine 1, so that it depends on the lubricating oil used thereafter. The corrosion state can be observed with higher accuracy. Here, since the surface 41a of the measurement member 41 is processed into a mirror-finished surface and becomes a corrosive observation surface, the measurement member 41 is used to prevent adhesion of soot and oil when the measurement member 41 is fixed and replaced. It is desirable to protect the surface 41a by sticking a sticker or the like on the surface 41a until the attachment.

  The measurement member 41 arranged in this manner begins to corrode its surface 41a as the deterioration of the lubricating oil proceeds as the internal combustion engine 1 operates. 4 and 5 show an example of an aspect in which the surface 41a of the measurement member 41 corrodes. 4 and 5 exaggerate the size of the corroded portion 71 for ease of explanation. When actually confirming the corrosion state of the surface 41a, it is magnified about 1000 times with a microscope and observed. First, in the initial stage of corrosion, as shown in FIG. 4, pitting corrosion occurs in which a certain point is locally corroded in a circular shape. As the corrosion progresses, the diameter d of the corroded portion 71 gradually increases. When the corrosion further proceeds, the corroded portion 71 expands along the crystal grains of the measurement member 41 as shown in FIG.

  The corrosion mode shown in FIGS. 4 and 5 is an example, but by correlating the progress of the corrosion by a test in advance, the correlation between the corrosion state of the surface 41a and the damage received by the internal combustion engine 1 is obtained. In other words, the damage received by the internal combustion engine 1 can be estimated by observing the corrosion state of the surface 41a. Further, since the measurement member 41 is left with traces of corrosion caused by the lubricating oil used in the past, the damage caused to the internal combustion engine 1 is estimated by observing these accumulated corrosion states. You can also. For this reason, by performing maintenance of the internal combustion engine 1 based on the observation result of the corrosion state of the surface 41a, it is possible to prevent the occurrence of problems and to extend the life of the internal combustion engine 1.

According to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the measurement member 41 made of metal is disposed at a position where the lubricating oil is immersed or struck, and the surface 41a of the measurement member 41 reacts with the lubricating oil and is corroded. By detecting deterioration of lubricating oil. Thus, by observing the corrosion state of the measuring member 41, it is possible to indirectly estimate the degree of adverse effects on the internal combustion engine 1 due to the use of deteriorated lubricating oil. For this reason, since it is possible to replace the lubricating oil and perform maintenance of the internal combustion engine 1 at an appropriate time based on the observed corrosion state, it is possible to prevent the occurrence of malfunctions, and to improve the length of the internal combustion engine 1. Life can be extended.

  (2) In the above embodiment, the deterioration of the lubricating oil is detected by observing the state in which the surface 41a of the measurement member 41 reacts with the lubricating oil and corrodes. Since the measurement member 41 is left with not only the lubricating oil currently used but also traces of corrosion caused by the lubricating oil used in the past, the internal combustion engine is based on the observation results of these accumulated corrosion states. Maintenance of the engine 1 can be performed.

  (3) In the above-described embodiment, the measurement member 41 has the surface 41a for observing the corrosion state processed into a mirror finish. For this reason, the change in the corrosion state of the surface 41a can be accurately observed.

  (4) In the above embodiment, the measurement member 41 is attached to the inner surface portion 51 a of the drain plug 51, the inner surface portion 52 a of the oil filler cap 52, or the tip portion 53 a of the oil level gauge 53. Since the measurement member 41 is attached to a member that can be attached to and detached from the internal combustion engine 1, the corrosion state of the surface 41a of the measurement member 41 can be observed by removing the member when checking or replacing the lubricating oil. It can be done easily.

  (5) In the above embodiment, the measuring member 41 is fixed to the drain plug 51 or the like by bolting or fitting, and is configured to be removable. For this reason, since the measurement member 41 can be easily replaced for each maintenance of the internal combustion engine 1, the corrosion state due to the lubricating oil used thereafter can be observed with higher accuracy.

In addition, you may change the said embodiment as follows.
In the above-described embodiment, the measurement member 41 includes the inner surface 51a of the drain plug 51, the inner surface 52a of the oil filler cap 52, the tip 53a of the oil level gauge 53, the service hole 54, or the inner surface 55 of the head cover 4. However, you may make it mount | wear to several places among these positions. By providing the measurement member 41 at a plurality of locations, deterioration of the lubricating oil can be detected with high accuracy. Further, the measurement member 41 may be mounted at a place other than these.

  In the above-described embodiment, the measurement member 41 is fixed to the drain plug 51 or the like by bolting or fitting. However, the measurement member 41 may not be configured to be fixed and removable by welding or the like, for example.

  In the above embodiment, the measurement member 41 is composed of a plate-like metal member having a thickness of about 1 mm, and the surface 41a is formed into a planar shape having a rectangular shape with sides of 10 to 20 mm. The member 41 does not have to be plate-shaped, and may be configured in any size and shape.

In the above embodiment, the surface 41a of the measurement member 41 is processed to have a mirror finish, but the surface 41a may not be processed to a mirror finish.
In the above-described embodiment, the measurement member 41 serving as the corrosion state observation portion is disposed inside the internal combustion engine 1, but the corrosion state observation portion may be integrally formed on the inner surface 55 of the head cover 4, for example. .

  -As another embodiment, you may use a part of metal member which can be attached or detached with respect to an internal combustion engine as a member for a measurement. For example, a part or all of the inner surface of the lid covering the service hole 54 can be processed into a mirror finish and used as a measurement member.

Sectional drawing which shows the structure of the internal combustion engine provided with the lubrication apparatus. The perspective view of the member for a measurement. (A), (b) is sectional drawing which shows the fixing method of the member for a measurement. The perspective view which shows the corrosion aspect of the surface of the member for a measurement. The perspective view which shows the corrosion aspect of the surface of the member for a measurement.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Cylinder cover, 5 ... Oil pan, 12 ... Piston, 13 ... Connecting rod, 14 ... Crankshaft, 18 ... Intake valve, 19 ... Exhaust valve, 20 ... Intake camshaft, 21 ... exhaust camshaft, 31 ... oil strainer, 32 ... oil pump, 33 ... oil filter, 34 ... oil gallery, 41 ... measuring member, 41a ... surface, 51 ... drain plug, 52 ... oil filler cap 53 ... Oil level gauge, 71 ... Corrosion part.

Claims (7)

  Deterioration of the lubricating oil in which a measuring member made of metal is arranged inside the internal combustion engine where the lubricating oil is immersed or landing, and the deterioration of the lubricating oil is detected by observing a change in the surface state due to corrosion of the measuring member Detection method. In a lubricating device that supplies lubricating oil to a sliding portion of an internal combustion engine,
A lubrication apparatus comprising: a measurement member made of a metal which is disposed at a position where the lubricating oil is immersed or struck and whose corrosion state changes with deterioration of the lubricating oil. The lubricating device according to claim 2, wherein
The lubrication apparatus, wherein the surface of the measuring member is processed to have a mirror finish. The lubrication apparatus according to claim 2 or 3,
The lubrication apparatus, wherein the measurement member is attached to a member that is detachable from the internal combustion engine. The lubrication apparatus according to claim 4, wherein
The lubrication apparatus, wherein the measurement member is attached to an inner surface portion of a drain plug, an inner surface portion of an oil filler cap, or a tip portion of an oil level gauge. The lubricating device according to claim 4 or 5,
The said measuring member is detachably provided with respect to the said detachable member. The lubricating device characterized by the above-mentioned. The lubrication apparatus according to claim 2 or 3,
A part of a metal member that can be attached to and detached from the internal combustion engine also serves as the measurement member.

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