JPH0476439A - Piston ring abrasion loss detecting device - Google Patents

Abstract

PURPOSE:To always measure an abrasion loss of a piston ring during motion of a piston by providing more than two of sensors for detecting an abrasion loss of a piston ring in the axial direction of a liner so as to convert signals from the sensor into electric signals, and by providing a microcomputer for calculating the abrasion loss of the piston ring. CONSTITUTION:A sensor block 5 incorporated therein with two or three gap sensors 4 is embedded in the lower part of a liner 3 so as to detect a contact length of a piston ring 2 in order to calculate an abrasion loss of the piston ring 2. That is, signals from the sensors 4 are inputted in a microcomputer 7 as electric signals by way of a signal converting amplifier 6. The microcomputer 7 carries out a waveform analysis so as to calculates the abrasion loss of the ring, and the result of the calculation is displayed on a display board 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piston ring wear amount detection device for an internal combustion engine.

[Conventional technology] Conventionally, the amount of wear on the piston rings of large diesel engines has been manually inspected by removing the pistons when docked or at port, which requires a great deal of labor and cannot be measured during the voyage. It is impossible to detect abnormal piston wear or predict when to replace it. There is also a system that measures the amount of wear by electrically detecting the thickness of the chrome plating on the - part, but it can measure only the initial wear, but cannot be used after the chrome plating disappears.

[Problems to be Solved by the Invention] As mentioned above, in the conventional ring wear measurement method, the piston is removed when the engine is stopped and the measurement is performed manually, which cannot be performed during a voyage and results in only discontinuous records. There was a drawback in this point.

In addition, to reduce ring wear, it is essential to increase the amount of cylinder lubrication, but this is adjusted manually to the extent that it is not too low considering economic efficiency.

For this reason, there has been a need for a piston ring wear detection device that can perform continuous measurement at all times and can be used to detect abnormal wear, predict when to replace the ring, and provide feedback for adjusting the amount of cylinder oil.

The purpose of the present invention is to solve the above-mentioned problems of the conventional device, to eliminate the need for manual measurement by removing the piston, which can significantly reduce labor, and to constantly measure the amount of wear during piston operation, thereby reducing the remaining life of the piston ring. By understanding this information and providing feedback to cylinder lubrication, it is expected that lubrication will be optimized and ring life will be extended. The present invention provides a piston ring wear amount detection device.

[Means for Solving the Problems] The piston ring wear amount detection device of the present invention is mainly composed of a gap sensor block, a signal conversion amplifier, a microcomputer, and a display device, and the piston ring wear amount detection device of the present invention is installed near the scavenging boat at the bottom of the cylinder liner of a diesel engine. A gap sensor 4 is installed to detect the passage of the ring through the contact surface. The piston ring has a trapezoidal cross section so that as wear progresses, the length of the contact surface with the liner increases.

The microcomputer 7 analyzes the signal from the gap sensor 4 and calculates the length of the contact surface between the ring and liner to determine the amount of wear.The microcomputer 7 sends a notification 8 of the amount of wear and other equipment 9 using a display or analog signal. Outputs the signal.

[Function] The gap sensor block 5 is attached to the lower part of the cylinder liner, and its electrical characteristics change when the piston ring passes in front of the block. The signal conversion amplifier 6 converts the signal from the gap sensor block 5 into an analog signal corresponding to the distance between the piston ring and the block and outputs the analog signal. The gap sensor block 5 and the signal conversion amplifier 6 are normally treated as a set.

The microcomputer 7 digitizes the analog signal from the signal conversion amplifier, performs various analytical calculations to determine the piston passing speed, calculates the contact surface length of the ring and liner, calculates the wear amount of the ring, and outputs it to the outside. I do.

The display 8 notifies the maintenance person of the output signal of the microcomputer 7 as the amount of ring wear.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram showing the principle of this device, FIGS. 2 and 3 are diagrams for explaining the operation, and FIG. 4 is a flowchart of the monitoring device.

As shown in FIG. 1, this device mainly includes a gap sensor block 5, a signal conversion amplifier 6, a microcomputer 7, and a display 8.

A sensor block 5 in which two or three gap sensors 4 are installed at the bottom of the liner as shown in Figures 3 (a) and (b).
is buried, the contact length of ring 2 is detected, and the wear amount of the ring is calculated. That is, the signal from the gap sensor 4 is input to the microcomputer 7 as an electrical signal via the signal conversion amplifier 6. The microcomputer 7 analyzes the waveform and calculates the amount of ring wear.

FIG. 2 shows the relationship between the shape of the ring 2 and wear.

If the end face of the ring 2 whose wear amount is measured by this device is partially machined into a trapezoidal shape as shown in FIG. 2, the contact length Lx with the liner 3 will increase as the wear of the ring progresses. That is, in order to detect the ring wear amount ε, the contact length LX
is measured and calculated using the following formula.

t = (Lx-Lo)X-
(1) L-L.

However, Lo is the total ring width and the initial contact length between the ring and the liner, and D is the chamfer depth of the ring.

FIG. 3(c) shows a gap sensor waveform and an analysis example. In the sensor block 5, the gap sensors 4 are arranged vertically at appropriate intervals Y as shown in FIG. The passing speed of the ring 3 can be found by dividing the sensor interval Y by the time difference Tv of the waveform 14 of the sensor 11.

The waveforms of the upper gap sensor 0 and lower gap sensor 11 are analyzed at the ring 2 passage judgment level to determine the passage time TL.
Detect. From the data obtained as described above, the current contact length Lx between the ring 2 and the liner 3 can be easily obtained from the following equation.

That is, to summarize the method for determining the wear amount E of the ring described above using this device, first, from a graph of the signal output from the sensor block 5 and time, the sensor interval Y is determined by the passing time Tr, and from the equation (2), the ring 2 is calculated. Find the current contact length Lx between and lie 3. Next, by substituting this Lx into equation (1), the ring wear amount E can be easily determined.

FIG. 4 shows a basic flowchart of the device. If the signal from the gap sensor 4 is also used for timing counting, wear can be detected not only for the first ring but also for all rings 2.

Also, if three gap sensors 4 are arranged on the top, bottom, left and right of the gap sensor block 5 as shown in FIG. 3(b),
The detection error near the abutment of ring 2 is determined by deleting the signal with the least amount of wear out of the three signals, and by deleting the signal with the least amount of wear among the three signals, and by deleting the detected contact length of ring 2 that is shorter than the initial design length, it is determined that the abutment is on the abutment. This can be solved by recognizing it.

[Effects of the Invention] Since the piston ring wear amount detection device of the present invention is configured as described above, it is possible to constantly measure the amount of wear while the piston is operating, and it is particularly useful for monitoring abnormal wear during voyages and understanding the remaining life of the rings. Feedback to cylinder lubrication is extremely effective in optimizing lubrication and extending ring life, and also eliminates the need for manual measurement by removing the piston as in the past, significantly reducing work effort.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the ring wear amount detection device of the present invention.
FIG. 2 is a diagram showing the relationship between the ring shape and wear, FIG. 3 is a diagram of the sensor waveform and an analysis example, and FIG. 4 is a basic flowchart. 1. Piston 52...Ring, 3...Liner, 4
...Gap sensor, 5...Sensor block, 6...
- Signal conversion amplifier, 7... Microcomputer, 8... Display panel, 10... Upper gap sensor, 11... Lower gap sensor.

Claims (1)

[Claims] A device for measuring the amount of wear on piston rings of an internal combustion engine includes two or more sensors arranged in the axial direction of a liner to detect the amount of wear on the piston rings, and a signal conversion amplifier that converts a signal from the sensor into an electrical signal. A piston ring wear amount detection device comprising: a microcomputer for calculating a piston ring wear amount.