JPS61187608A - Piston ring for internal-combustion engine and method for detecting abrasion thereof - Google Patents

Abstract

PURPOSE:To make it possible to certainly detect the abrasion advance state of a coated piston ring, by imparting the stepwise abrasion marks of the coating layer of a piston ring to the lubricant supplied to the slide surfaces of the piston ring and a cylinder liner. CONSTITUTION:A coated piston ring 11 is constituted of a base material 11a, coating layers 11b, 11c comprising chromium plating and detection layers 11d, 11e. By depositing the second detection layer 11e to the base material 11a, the release of the coating layer 11c is prevented when the residual thickness of said coating layer 11c became thin because of abrasion and forecasting allowance is imparted when the coating layer 11c disappeared. When the piston ring 11 is mounted to a piston 11, elements constituting the abraded powder mixed in lubricant change with the elapse of time. This abraded powder is analyzed by a metal detector to detect the abrasion advance state of the piston ring 11. If the number of the coating layers of the piston ring and the depths thereof are preliminarily determined, the residual amounts of the coating layers can be estimated without cutting the piston ring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the wear detection direction of internal combustion IaIJIi piston rings and the wear detection direction of internal combustion IaIJIi piston rings. For the purpose of imparting wear resistance to the outer circumferential surface of the ring, for example, chromium is attached by electroplating, a Shimunotsuki ring, or a so-called plasma sprayed ring in which a hard composite material whose main component is alumina is adhered using plasma spraying technology. The present invention relates to a coated piston ring and a method for detecting wear of the piston ring.

Background technology Internal combustion engine, especially marine diesel? Recently, the combustion pressure of Jllii has been increasing significantly in order to improve thermal efficiency. As a result, piston rings that support combustion pressure tend to wear out faster and have a shorter lifespan. Therefore, in order to extend the life of the piston ring, a piston ring having a coating layer (hereinafter referred to as a coated piston ring) is used C2.

Such a coated piston ring is shown in FIG. The coated piston ring 1 is composed of a base material 1a and a coating layer 1b. The base material 1a of this piston ring is made of, for example, special bonded steel, and is coated with chromium on its outer periphery by electroplating, or by bonding a hard composite material containing alumina as a main component by plasma spraying. 7! 1b is constructed. Such a cover 1 [11b
The chrome plating layer or the plasma sprayed composite material layer is significantly harder than the base material 1a, and maintains a good bistiling life even under high combustion pressure. It is considered possible. In addition, in reality, if the fuel properties are relatively good, it is possible to secure a long life of more than 10,000 continuous cycles in a marine diesel engine by using a coated ring. there were. Therefore, the thickness of the coating layer 1b should be set to a thickness that allows for a certain amount of wear over the course of about two years. For example, it is possible to easily estimate the operating life of the coating layer from the wear thickness per unit time, and the piston ring 1 must not be cut after that (applicable to diesel engines using the piston ring 1). there were.

However, in recent years, in order to improve economic efficiency and thermal efficiency, the use of low-quality fuel oil in marine motors has steadily increased.

Low-quality fuel oil not only contains hard foreign substances such as catalysts that cannot be completely recovered, but also increases the amount of residue generated by combustion. Furthermore, the combustion period is longer than with high-quality fuel, and in the case of a diesel engine, for example, the operating temperature of reciprocating parts such as the cylinder liner and piston ring among the parts that make up the cylinder increases. As a result, the lubrication conditions between the cylinder liner and piston ring deteriorated considerably due to the increase in operating pressure, the presence of foreign matter, and the decrease in lubricant viscosity due to the increase in operating temperature. However, wear will progress rapidly.

Since ocean-going ships load fuel around the world, the properties of the fuel oil vary, and an unspecified ratio of high-quality and low-quality fuel oil is used. In addition, hard Y is mixed in low-quality fuel oil! The grains and diameter of TY4 particles are very small, and it is impossible to visually identify them without a high-magnification microscope, so operators of marine diesel engines end up using low-quality oil without realizing it. Under such marine fuel conditions, it is difficult to estimate how long the coated piston ring 1 has remaining operating life. The conventional technology is to measure the wear of piston rings by making piston rings containing radioactive isotopes and measuring the released wit, but it is difficult to handle and it is extremely difficult to put it into practical use in commercial engines.゛. (H, Typhoid: Tribology (P. 22)
3-225) M story (1980)] If a piston ring whose service life has expired is used, the hard coating layer may peel off, or the adhesive surface of the coating scrap and base metal may come into contact with the cylinder liner. M of cylinder liner! Damage JJ's face,
This can cause serious damage to the engine, including scuffing of the piston ring and cylinder liner, and even seizure of the piston and cylinder liner.

Problems to be Solved by the Invention In summary, coated pea stone rings wear from the outer peripheral surface of the coating layer 1b over time, but since the coating material is homogeneous, the sliding surface wears out. During the process until it retreats to the outer peripheral surface of the base material 1a, the piston ring 1
The abrasion powder does not change in terms of material.On the other hand, the point at which the driving surface retreats to the bonding surface between the coating layer 1b and the base material 1a is the point at which the remaining operating life has been lost, and this means the point at which a serious accident begins. Even if it is assumed that the abrasion powder of the base material 1a can be detected by a highly sensitive detector, it will be difficult for the engine operator to continue normal operation simply by stopping *m. On the other hand, a ship whose engine has stopped running loses its motive power, and its safety is at risk.

An object of the present invention is to provide traces of wear to the lubricating oil supplied to the sliding surfaces of the piston ring and cylinder liner in stages as the coating layer of the piston ring wears out, thereby monitoring the progress of wear of the coated piston ring. An object of the present invention is to provide a method for detecting wear of a piston ring for an internal combustion engine, and a piston ring for an internal combustion engine, which can reliably detect wear.

Means for Solving the Problems The present invention forms a high-strength coating layer on the outer periphery of the base material of the piston ring, and this coating layer is in sliding contact with the cylinder liner, and is designed to supply lubricating oil to the sliding contact area. In the method for detecting wear of a piston ring for an internal combustion engine, a detection layer is provided in the middle of the piston ring in the radial direction, the detection layer is made of a metal different from that of the cylinder liner and the coating layer, and is made of a metal different from that of the cylinder liner and the coating layer. Internal combustion characterized by detecting the composition of metal powder contained in it 8! Sekikawa This is a method for detecting wear on piston rings.

In addition, Ike's invention forms a coating layer around the outer periphery of the base material of the piston ring, and a detection layer is provided in the middle of the coating layer in the radial direction, and this detection layer is made of a metal different from that of the cylinder liner and the coating layer. This is a large piston ring for internal combustion, in which the detection layer is divided in the circumferential direction or the axial direction.

Function Since the wear particles of the piston ring are extremely fine particles, the wear particles float in the lubricating oil supplied to the sliding surfaces of the piston and cylinder liner, and circulate through the lubricating oil piping system. Lubricating oil contains not only wear particles from piston rings, but also cylinder liners, bearings, and other internal combustion particles.
Abrasion particles from the seki component parts are also floating. Therefore, in order to identify changes in the wear state of the piston ring coating layer, the material of the detection layer provided on the piston ring coating layer must be a material that is not included in other engine parts. It is required to have good compatibility with the sliding surface of the cylinder liner, without leaving any gaps, and to have a characteristic that V-bonds with the piston ring coating material or base material. By detecting metal powder in the detection layer made of such a material, the progress of wear of the piston ring can be detected.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention. A piston ring 11 provided on a piston 10 of an internal combustion engine is in sliding contact with an inner circumferential surface 12a of a cylinder liner body 12. The cylinder liner main body 12 is made of cast iron in order to improve slidability with the piston ring 11. The piston ring 11
Yes, it is a coated piston ring. This coated piston ring 11 has a base material 11 as shown in FIG.
a, a coating 111b made of chrome plating,
It is composed of detection layers 11d and 11e. detection layer li
For example, silver is a suitable material for the base material 11u and the coating layers 11b and llc.
If the material has good adhesion to the cylinder liner material, is compatible with the cylinder liner material, and is different from other engine components, there is no need to specify the material. For example, nickel, copper, etc. are materials that can be found in abundance. The thickness of the detection layer 11d1118 may be sufficient to fill the unevenness of chromium from the coating layer/H11b+11c and to allow the detection layer 11d+11e to exist, for example, about 5 to 6 μm thick. Since the wear rate of piston rings for marine diesel engines with a shilling diameter of 400 to 500 a++e and an output of 500 to 1000 ps per shilling is 20 to 30 μ per 1000 hours, this detection layer lid, l
The thickness of ie corresponds to a wear allowance of 200-300 operating hours. On the other hand, the total thickness of the covering layer 11b and lie is 0.3
~0.5m crane length, operating life is 1oooo~i5
Since the time is ooo, the rate of decrease in the @*capacity of the coating layer can be ignored.

Note that the detection layer 11d is coated with the total thickness l of the coating layers 11b and 11e.
If the lubricating oil is attached to a depth of 1/2 +o, a detection indication can be given to the lubricating oil circulating inside the diesel engine when the remaining operating life reaches 172 of the operating life. Moreover, if the depth h is further increased, it can be predicted that the operating life is very near. The depth h is determined depending on what kind of wear management is to be carried out. The coating layer 11 adheres the second detection layer lie to the base material 11a.
This is to prevent C from peeling off even if the remaining thickness of C becomes thin due to wear, and to provide a short notice margin even if the coating layer ie disappears.

In this example, the number of detection layers is 2 including the boundary layer with the base material.
However, if the number of detection layers is increased to 3M or 4, the effect will be greater, such as more accurate estimation of wear life, but the principle is the same as that of the present invention.

FIG. 3 is a lubricating oil piping system diagram for internal combustion according to the present invention. The lubricating oil stored in the oil tank 20 is supplied by a pump 21 to each cylinder 22 of the internal combustion engine via the line 1. 114 of the piston 10 in each cylinder 22
The lubricating oil used in 9h is stored in the oil tank 20 via the oil pan 23. Then, it is applied again to the cylinder 22 by the pump 21. This series of operations is repeated to constantly supply lubricating oil to the internal combustion engine.

The line 71 is provided with a metal detection device 24 for detecting wear particles in lubricating oil. When the piston ring 11 according to the present invention is mounted on the piston 10 of an internal combustion engine,
As time passes, the elements constituting the wear particles mixed into the lubricating oil change. This wear powder is analyzed by the metal detection device 24, and the progress of wear of the piston ring 11 is detected.

FIG. 4 is an explanatory diagram schematically showing changes in elements in the lubricating oil with the passage of operating time in this embodiment. In this embodiment, the cylinder liner main body 12 and the piston ring base material 11m1. : Trace the contained iron Fe1, chromium Cr constituting the coating layer 11b*11c of the piston ring, and silver A constituting the detection layer 14d and lie. The technology for collecting foreign matter in lubricating oil has been around for a long time, such as the 7-erography technology, and has recently progressed steadily, so there is no problem with the collection itself. Furthermore, there are various detection methods such as atomic absorption spectrometry, emission spectrometry, etc. for detecting trace amounts of elements i, but since the wear of the piston ring 11 is to be traced to a specific element, a relatively easy analysis method can be applied. FIG. 4(a) shows the wear particles during the period when the coating layer 11b of the piston ring 11 is moving relative to the cylinder liner body 12, as shown in FIG. The element detection status is schematically shown. Cylinder liner body 12
Iron (Fe), which is the main wear debris, was detected along with 11 lb of chromium (Cr) in the coating. #IJ4 Figure (b) schematically represents the state of detection of the abrasive and dry powder elements at the time when the coating waste 11b is almost worn away. Covered 1! [11
Chromium Cr constituting 1b decreases, and silver Ag constituting detection M11d begins to be detected. FIG. 4(c) schematically shows the state of wear powder elements at the time when the detection Ml ld is in contact with the cylinder liner body 12.
Silver All, which is the material of d, is detected.

As the operating time continues to elapse, Fig. 4(a), ! @Figure 4 (
b) The situation shown in FIG. 4(a) will be repeated. FIG. 4(d) shows that the detection layer 11e in contact with the piston ring base material 11a is about to wear out when the cylinder liner 12
In this state, the detection p 11
In addition to the silver constituting e, iron is discharged into the lubricating oil from both the cylinder liner 3 and, depending on the location, the piston ring material 11m, so the concentration of iron increases significantly. At this point, the piston ring 11 is MM 1 l b, 1
1 'c reaches the end of its life. In this way, according to this embodiment, by determining the number and depth of the piston ring coating layer in advance, the remaining amount of the coating layer can be easily estimated in a non-destructive state without cutting the piston ring. This can be expected to have a great effect not only on abnormal wear detection and failure prediction of piston rings for internal combustion engines, but also on maintenance management.

The detection layers lid and lie may be cut and buried in the width direction of the piston ring 11 as shown in FIG. 5, or may be partially buried in the circumferential direction of the piston ring 11 as shown in FIG. The fifth example may be
In the embodiments shown in Figures to Figures 6, the amount of metal material in the detection layer is smaller than in the embodiment shown in Figure 1, so it is necessary to increase the sensitivity of the sensor that detects the same metal material. Since the metallic material is surrounded by the coating material, there is an advantage that the strength of the coating material is less reduced.

Effects of the Invention As described above, according to the present invention, it is possible to reliably detect the progress of wear of piston rings.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a cross-sectional view of a piston ring, Fig. 3 is a lubricating oil piping system diagram of an internal combustion engine according to the present invention, and Fig. 4 is a diagram illustrating a diagram of a lubricating oil piping system according to an embodiment of the present invention. An explanatory diagram structurally showing changes in elements in lubricating oil for this example,
5 and 6 are cross-sectional views of other embodiments of the piston ring, and FIG. 7 is a view showing the prior art. 11...Piston ring, 11 m''/Base metal, 11
b. 11c...covered [7! ! , 11dtl 1e ・=Detection layer, 12-... Schilling Quina main body, 24... Metal detection 11 Agent Patent attorney Number of strokes Keiichi Figure 1 Figure 2 Figure 3 Figure 4 (a) (b) Fe Cr FeCrAg(C'
)(d)

Claims (2)

[Claims] (1) Wear of a piston ring for an internal combustion engine in which a high-strength coating layer is formed on the outer periphery of the piston ring base material, this coating layer slides on the cylinder liner, and lubricating oil is supplied to this sliding contact point. In the detection method, a detection layer is provided in the coating layer at an intermediate position in the radial direction of the piston ring, and the detection layer is made of a metal different from that of the cylinder liner and the coating layer, and detects the composition of metal powder contained in the lubricating oil. A method for detecting wear of a piston ring for an internal combustion engine, characterized by: (2) Forming a coating layer on the outer periphery of the base material of the piston ring,
The coating layer is provided with a detection layer at an intermediate position in the radial direction, the detection layer is made of a metal different from that of the cylinder liner and the coating layer, and the detection layer is divided in the circumferential direction or the axial direction. Piston rings for internal combustion engines.