JPS62280651A - Scuffing detector for internal combustion engine - Google Patents

Abstract

PURPOSE:To decide the occurrence of scuffing in its early stage by fitting an AE sensor to a cylinder liner and detecting acoustic emission due to the scuffing. CONSTITUTION:An AE sensor 20 which detects the abnormal sound (acoustic emission of an ultrasonic wave generated due to a local border lubricant state is fitted onto the outside of the lower end part of the cylinder liner 13. The detection signal of the sensor 20 is inputted to a decision processing circuit 23 through a preamplifier 21 and a main amplifier 22. The normal AE sensor 24, on the other hand, is fitted to a cylinder cover 16 and its detection signal is inputted to the circuit 23. The circuit 23 compares the maximum amplitudes of the sensors 20 and 24 with each other to decide the occurrence of scuffing and outputs it to a display device 26 and an alarm 27. Consequently, the scuffing is detected in its early stage. When an internal combustion engine is a multicylinder engine, the AE sensor of another cylinder is usable as the normal sensor.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a method for detecting scuffing of piston rings, etc. of an internal combustion engine by using acoustic emissions. This makes it easy to determine whether or not it exists.

(Prior Art) One of the damages that occur between the piston and cylinder liner or between the piston ring and cylinder liner is the scuffing phenomenon.

This scuffing phenomenon is often caused by local boundary 1171 slippage that occurs for some reason. - If loss force scuffing occurs, the operation must be stopped and a lot of time and money will be spent. This means that you will have to replace the screws, rings, screws, and even the cylinder liner.

Therefore, it is extremely important to detect signs of scuffing before it occurs and take countermeasures, but scuffing cannot be directly monitored from outside the internal combustion engine.

Therefore, conventionally, when a boundary lubrication state occurs, the temperature of that part increases, and as shown in FIG. There is a system in which a low temperature antibody is installed as a number sensor 3, and a detection signal from the temperature sensor 13 is used to operate an alarm 4 based on the temperature increase rate or comparison with a set temperature. .

[Problem that the invention seeks to solve]

However, when detecting temperature with such a temperature sensor 3 and monitoring the boundary lubrication state, which is a sign of scuffing, the boundary fy is detected at the part where the temperature sensor 3 is installed.
If I slip occurs, it can be detected at an early stage, but an abnormality in a slightly distant area cannot be detected at all.

Therefore, problem F can be solved by installing a large number of temperature sensors, but there are structural limitations of the internal combustion hoe, such as the need to avoid interference with the cold RJI water flow path, etc.

In addition, thermocouples, resistance temperature sensors, etc. have a large heat capacity 8, which cancels out the temperature rise that occurs in the local boundary lubrication state, and when an alarm is issued based on the detection signal of temperature sensor +lJ3, scuffing is considerably reduced. The disease progresses and early detection is difficult.

The present invention has been made in view of the prior art, and an object of the present invention is to provide a scuffing detection device for an internal combustion engine that can detect scuffing in an internal combustion engine at an early stage and easily determine whether or not scuffing is occurring. be.

[Means for solving problems]

In order to solve the above problems, the scuffing detection device for an internal combustion engine of the present invention includes an AE sensor (4) installed in the cylinder liner of the internal combustion engine for detecting acoustic emissions due to scuffing, and a normal A sensor for detecting acoustic emissions in a normal state. [In the case of a single-cylinder engine, the sensor is installed at any position on the internal combustion engine, and in the case of a multi-cylinder engine, the E sensor installed in the other cylinders is installed in the normal A
The present invention is characterized in that it is provided with a determination processing circuit which also serves as the E sensor and compares the maximum amplitudes of the detection signals from the E sensor and the normal AE sensor to determine the occurrence of scuffing.

[For production]

An AE sensor that detects acoustic emissions is installed on the cylinder liner of an internal combustion engine, and abnormalities due to scuffing are detected by the AE sensor.In order to determine whether or not this detection signal is scuffing, the acoustic emissions in a normal state are detected by the AE sensor. It is detected by an AE sensor, but in the case of a single cylinder, a normal AFL is installed in addition to the cylinder liner and used, while in the case of a multi-cylinder, the AE sensor installed on the cylinder liner is also used. , the maximum amplitude of the detection signal of the AE sensor and the normal AE sensor is compared in the judgment processing circuit, and the
It is determined that scuffing has occurred when the distance is smaller than m.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment in which the intercondylar scuffing detection device of the present invention is applied to a single-cylinder internal combustion engine.

In this single-cylinder internal combustion engine 10, a crankshaft 12 is provided at the lower part of a frame 11, and a cylinder liner 13 is attached to the upper part. It is connected to the crankshaft 12 via a connecting rod 15. A cylinder cover 16 is attached to the upper end of the frame 11 to form a combustion chamber, and an oil pan 1 is attached to the lower end.
Several parts of 7 have been cut out so that lubricating oil can be added.

In order to detect scuffing in the single-cylinder internal combustion engine 1o, an AE sensor 20 for acoustic emission detection is attached to the outside of the lower end of the cylinder liner 13.

The AEt7 sensor 20 used includes an ultrasonic transducer that detects an abnormal ultrasonic wave (acoustic emission) generated by a local boundary W lubrication state.

The detection signal from this AE sensor 20 is inputted to the main amplifier 22 via a preamplifier 21 installed on the machine side, for example, on the outer wall of the frame 11, and then inputted to the determination processing circuit 23 via this main amplifier 22. ing.

On the other hand, internal combustion FMI! In order to detect acoustic emissions under normal operating conditions in which scuffing does not occur on the cylinder cover 110, the normal AE sensor 24
6 (in the illustrated example, the side),
A detection signal is input to the main amplifier 22 via the preamplifier 25. This normal AE sensor 24
The same configuration as the AE sensor 20 is also used.

Further, the judgment processing circuit 23 is connected with a display 26 for displaying the judgment processing result and an alarm 27.
The presence or absence of scuffing is displayed, and a warning is issued if scuffing occurs.

Next, the determination processing of the scuffing detection device in the case of a single cylinder configured as described above will be explained with reference to FIGS. 2 and 3.

The signals detected by the AEt7 sensor 20 and the normal AE sensor 24 during operation of the internal combustion engine 10 change depending on the stroke of the internal combustion engine 10, and reach the maximum system width during the exhaust stroke.

Therefore, the maximum amplitude of No. 1g (see FIG. 2 (1)) detected by the normal AE sensor 24 in a normal state without scuffing is defined as a.

Similarly, AEt? Let ao be the maximum amplitude of the signal (see FIG. 2(C)) detected by the engine 21 in a normal state without scuffing (operating conditions are the same as FIG. 2(b)).

Are these normal AEIs? The maximum amplitude a by the door sensor 24 and the maximum amplitude a by the A door sensor 21. varies depending on the operating condition of the internal combustion engine 10, especially the load, but since there is a correlation between the two as shown in FIG. It is stored in the fertilization process 23.

Next, if a local boundary lubrication condition, which is a sign of scuffing, occurs in the cylinder liner 3 of the internal combustion engine 10 under such conditions, ΔE
The horizontal 1°1 signal of the t7 axis 21 changes as shown in FIG. 2(d), and its maximum amplitude increases to a'.

Therefore, if the determination processing circuit 23 determines whether the maximum amplitude a' is normal or abnormal, the occurrence of scuffing can be detected.

In this case, even if initial scuffing (local boundary lubrication state) occurs in the cylinder liner 13, whether the normal AEI installed on the cylinder cover 16 is normal? In the sensor 24, the amplitude increase due to scuffing is reduced, and the normal AE sensor 24
The detection signal is equal to the normal detection signal corresponding to the operating load (<-2), and the maximum amplitude remains a.

Therefore, from the maximum system width a of this normal AE sensor 24, a and a are stored in the determination processing circuit 23. Based on the relationship, the maximum amplitude ao that should be detected by the AE sensor 21 of the cylinder liner 13 in a normal state is estimated.

From this, the estimated maximum system width a. and the measured maximum amplitude a', and when a'>a, O
OO, it is determined that there is an abnormality, and this is output to the display 326 and the male steamer 27, indicating that scuffing is occurring, and at the same time issuing an alarm.

Is AEI normal like this? From the maximum amplitude a detected by the sensor 24, the maximum system width aO during normal operation of the AE sensor 21 is calculated as 11
[This and the measured maximum amplitude a. By comparing ', it is possible to easily determine the occurrence of local boundary lubrication, which is a sign of scuffing.

Next, an embodiment in which the present invention is applied to a multi-cylinder internal combustion engine will be described with reference to FIG. 4N and FIG. 5.

In addition, the same function parts as the single cylinder in each part of the internal combustion engine are
The number M is written, and subscripts 1 to 3 are attached to each cylinder.

To detect scuffing in the internal combustion engine 100, each cylinder liner 31, 13 . ．． , AEt? for acoustic emission detection on the outside of the lower end of 133? 20. 20. 203 are the respective attachments.

These AE sensors 20. 20. The detection signals from 203 are sent to preamplifiers 211, 21 . 213 to the main amplifier 22, and this main amplifier 2
2 to the judgment processing circuit 23, and the judgment processing circuit 23 includes a display 26 and a ¥R alarm 2.
7 are connected.

In the case of this multi-cylinder internal combustion engine 1111100, the AE sensor 2 is installed in a cylinder other than the cylinder to be detected as a normal AE sensor for detecting acoustic emissions under normal operating conditions without scuffing.
0 is used, for example when detecting the first cylinder liner 31, the second and third cylinder liners 3
．． AE sensor 20.203 attached to 133 is used as a normal AE sensor.

Note that the signal processing may be performed on the AE sensors of all cylinders including the cylinder to be detected as normal AE sensors.

Next, the determination processing of the scuffing detection device in the case of a multi-cylinder engine configured as described above will be explained with reference to FIG.

Even in this multi-cylinder internal combustion engine 100, AEt = length 2
0. 20. The signal detected by 203 changes with the stroke of the internal combustion engine 100, regardless of whether scuffing occurs, and reaches its maximum amplitude during the exhaust stroke.

Therefore, each cylinder liner 3. The maximum amplitude F3. Find a, a.

And these maximum amplitudes a. 1. o2. The determination processing circuit 23 outputs a signal to compare each of ao3 with each other, set the maximum value as a, and display this cylinder on the display 26.

At the same time, calculate the average ll[aIll of the maximum amplitude from the values of the remaining cylinders among the maximum amplitudes, and add α to this average value.
% error is set, a' is set, and the set value a' and the maximum amplitude a in the AE sensor 20.

(2) The maximum value a is compared, and when a≧a', it is determined that scuffing has occurred.

In addition, the AEt7 sensor of each cylinder is 20.20□.

Maximum amplitude a, a3 from the measured value of 20
After selecting the maximum value a of 01, 02, and 803, when calculating the average of the maximum amplitudes 1iiiW a , the maximum amplitudes of all cylinders including the cylinder with the maximum value a may be used, and in this case, the set value a ′ is given by the following equation.

Here, N is the number of cylinders, α is the error range, for example α = 0
．． Give like 05.

When the number of cylinders in the internal combustion engine 100 is small, a set value a' is determined from the maximum amplitude of all cylinders, and this set value a' is combined with the maximum amplitude ao1 of each cylinder. ao2. a
o3 may be sequentially compared and the cylinder number and occurrence of scuffing may be displayed on the display 26.

In this way, the average of the maximum amplitude of the signal multiplied by ΔE is 1 direct a.

The set value a′ found from and the maximum amplitude a of the AE signal at any cylinder. , (N = 1.2...) are compared, and if a is large, it is determined that scuffing has occurred, so it is possible to detect the occurrence of scuffing on the m instep.

〔Effect of the invention〕

As specifically explained below with the embodiments, according to the scuffing detection device for an internal combustion engine of the present invention, internal combustion
Attach an AE sensor to detect acoustic emissions to the cylinder liner of n, and install a normal △E sensor to detect acoustic emissions in the normal state, and compare the maximum amplitude of the detection signal from these AE sensors and the normal AE sensor. The occurrence of scuffing is determined by a judgment processing circuit. Compared to the conventional method of detecting local boundary lubrication, which is a precursor to scuffing, from temperature changes, it is possible to detect scuffing more quickly without problems such as thermal bulk. It can be detected quickly and countermeasures can be taken before serious damage occurs.

In addition, there are no restrictions on the installation location of the AET sensor used for detection, and at least one sensor can be installed at any location on the cylinder liner.
If the membrane is thin, local boundary vI slippage can be detected regardless of where it occurs.

Furthermore, since only the maximum amplitude of the AE signal is used to determine the occurrence of scuffing, the processing of the AE signal is simple, and the determination processing circuit is also a successor.

Further, even if the amplitude of the detection signal changes depending on the operating state of the internal combustion engine, especially the load, local boundary lubrication, which is a sign of scuffing, can be detected without being affected by this.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment in which the scuffing detection device for an internal combustion engine of the present invention is applied to a single-cylinder internal combustion engine, with Figure 1 being a schematic diagram and Figure 2 being an explanatory diagram of a detection signal. ,
FIG. 3 is an explanatory diagram of the relationship between the detection signals of the AE sensor and the normal AE sensor, and FIGS. 4 and 5 are schematic configuration diagrams and detection diagrams of an embodiment in which the invention is applied to a multi-cylinder internal combustion engine. FIG. 6, which is an explanatory diagram of signals, is a schematic configuration diagram of a conventional device. 10.100...Internal combustion l1wJ, 13...Cylinder live, 16...-cylinder cover, 20...AE
Sensor, 21... Preamplifier, 22... Main amplifier, 23... Judgment processing circuit, 24... Normal AE sensor, 25... Preamplifier, 26... Display unit, 27...
...Alarm, a, ao, a'... Maximum amplitude. Applicant Ishikawajima Harima Tan Kogyo Co., Ltd. (1-7J1)

Claims (1)

[Claims] An AE sensor that detects acoustic emissions due to scuffing is installed on the cylinder liner of an internal combustion engine, and a normal AE sensor that detects acoustic emissions in a normal state is installed, and the maximum amplitude of the detection signal from these AE sensors and the normal AE sensor is compared. 1. A scuffing detection device for an internal combustion engine, comprising a determination processing circuit that determines the occurrence of scuffing.