JPH04124444A - Abrasion monitoring method of piston ring and device thereof - Google Patents

Abstract

PURPOSE:To monitor always an abrasion amount during operation, by detecting the thickness in a diameter direction on the basis of a time difference in reception respective reflected waves coming from the outer and inner circumference surfaces, in supersonic wave which is transmitted from the outer circumference surface of a cylinder liner. CONSTITUTION:Ultrasonic wave is transmitted from a cylinder liner outer wall 5 toward a piston ring 2. The thickness (T) of the piston ring 2 in the diameter direction is detected on the basis of a time difference in reception between reflected wave which is reflected oh the piston ring outer circumference surface 6 and reflected wave which is received by an ultrasonic wave sensor 3. It is thus possible to know always abrasion state of the piston ring 2 from the outside of an engine without inspecting by opening the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for monitoring wear of piston rings of an internal combustion engine.

[Conventional technology]

Fig. 3 shows a conventional internal combustion engine without a piston ring wear monitoring device. The piston ring 2 attached to the piston 4 slides on the inner surface of the cylinder liner and gradually wears out during engine operation. If the amount of wear on the piston rings 2 exceeds the usage limit, compression will decrease, so the amount of wear on the piston rings must be measured at least periodically. Conventional methods for measuring piston rings include the following (2).

(1) Remove the cylinder cover 12 from the engine, remove the piston ring 2 from the piston 4, measure the thickness of the piston ring 2 directly with a measuring device such as a caliper, and calculate the amount of wear from the dimensional difference with the new piston ring. measure. After the measurement is completed, it is attached to the piston 4 again, inserted into the cylinder, and the cylinder cover 12 is attached to the engine 8.

(2) The abutment dimension A of the piston ring 2 increases as the piston link 2 wears.

Therefore, the measurer enters the scavenging trunk 13 of the engine,
Move the piston so that the piston ring 2 is in front of the scavenging port 14 at the bottom of the cylinder liner 1, measure the abutment dimension A through the hole in the scavenging boat 14, and determine the amount of wear from the difference in the abutment dimension of the piston ring with the new one. calculate.

[Problem to be solved by the invention]

However, each of the above-mentioned conventional methods for measuring the wear amount of piston rings has the following drawbacks.

(1) Method of measuring piston ring wear directly from the engine.

■Stop the engine and remove the piston 4 from the cylinder cover.
Remove the piston ring 2, measure the piston ring 2, and reassemble the engine. Therefore, the engine cannot be operated until then.

■Also, it costs a lot of money and time to remove and attach the piston 4 to the cylinder cover.

■If the engine cannot be stopped freely, such as for power generation or marine engines, there are restrictions on the measurement time.

■Since the amount of wear cannot be measured constantly, it is not possible to detect at an early stage even if piston ring wear progresses rapidly due to deterioration of engine operating conditions, such as deterioration of the fuel used.

(2) A method of measuring piston ring abutment dimensions from the scavenging trunk of the engine.

As in case (1) above, measurement cannot be performed unless the engine is stopped, so there are the same drawbacks as in ■, ■, and ■ above, and in addition, the inside of the scavenging trunk is a high temperature, high humidity, closed place, and dark place.
There are drawbacks such as the measurement work being dangerous.

An object of the present invention is to solve the problems of the conventional device, eliminate the need for an open inspection of the engine, and eliminate the need for people to go in and out of the engine, and a method and device for monitoring piston ring wear during operation. is to provide.

[Means to solve the problem]

The piston ring wear monitoring method and device of the present invention include:
Ultrasonic waves are transmitted from the outer circumferential surface of the cylinder liner toward the piston ring, and the reflected waves reflected from the outer circumferential surface of the piston ring and the reflected waves reflected from the inner circumferential surface of the piston ring are received by ultrasonic sensors.

[For production]

The thickness of the piston ring is determined by the time difference between the reflected waves reflected from the outer peripheral surface of the piston ring and the reflected waves reflected from the inner peripheral surface of the piston ring until they are received by the ultrasonic sensor installed at the front transmission location. be measured. By comparing this with the dimensions of a new piston ring, the amount of wear can be measured.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is an explanatory diagram of the principle of the embodiment, and FIG. 2 is an overall configuration diagram of the embodiment.

In FIG. 1(a), an ultrasonic sensor 3 consisting of an ultrasonic transmitter and an ultrasonic receiver sensor is attached to the outer wall 5 of one cylinder liner 1. On the other hand, the piston rings 2 are usually mounted in four or five stages in the ring groove of the piston 4. FIG. 1(a) is a schematic diagram when the ultrasonic sensor 3 and the piston ring 2 are in positions facing each other with the cylinder liner interposed therebetween.

In order to constantly detect the wear amount of the piston ring 2 during engine operation, a piston ring position detection mechanism is additionally required, and FIG. 2 shows the overall configuration of the piston ring wear monitoring device of the present invention.

A position detection signal is generated at a predetermined timing when the piston ring position is determined by a marker 10 attached to the flywheel 9 of the engine 8 and a position sensor 11, and the timing is when the ultrasonic sensor and the piston ring are at the same level. Find out.

The controller of the ultrasonic sensor causes the ultrasonic sensor 3 to emit ultrasonic waves based on the signal from the piston ring position sensor 11, and detects the thickness of the piston ring according to the procedure shown in FIG. 2.

Next, the operation of the above embodiment will be explained.

As shown in FIG. 2, the position detection sensor 11 disposed around the flywheel 90 detects that the piston ring 2 is at the level of the ultrasonic sensor 3, and this timing is detected by the ultrasonic sensor 3. Piston ring 2 that tells
When the ultrasonic sensor 1 and the ultrasonic sensor 1 are in the positional relationship shown in FIG. Accordingly, a B wave reflected from the piston ring outer circumferential surface 6 and an A wave reflected from the piston ring inner circumferential surface 7 after passing over the cylinder liner inner wall 6 along the ultrasonic transmission path A are generated. Therefore, as shown in FIG. 1(b), on a graph where the vertical axis is the sensor output of the receiving sensor in the ultrasonic sensor 1, and the horizontal axis is the elapsed time from the time when the ultrasonic wave was transmitted as the starting point, Three types of reflected wave outputs as shown in b) are generated. Here, when the sound velocity in the piston ring 2 is V8, the ring thickness T is calculated from the time difference TR between the B-wave echo and the A-wave echo using the following formula.
If the measured value of is Ti, then when the measured value at a certain point in time during which wear is being measured is T, the amount of wear ΔT is calculated by the following equation: ΔT=T i −T.

[Effects of the Invention] Since the present invention is constructed as described above, the wear status of the piston rings can be known at all times from outside the engine without having to perform an open inspection of the engine.

Therefore, even if abnormal wear of the piston rings occurs due to deterioration of engine usage conditions such as deterioration of the fuel used, the problem can be detected early, preventing the development of a major accident. There is no need for workers to go in and out of the engine, making it possible to reduce dangerous work.

[Brief explanation of the drawing]

1 and 2 are related to the present invention; FIG. 1 is an explanatory diagram of the principle of an embodiment, FIG. 2 is an overall configuration diagram of the embodiment, and FIG. 3 is a sectional view of a conventional internal combustion engine. DESCRIPTION OF SYMBOLS 1... Cylinder liner, 2... Piston ring, 3... Ultrasonic sensor 1, 4... Piston, 5...
... Cylinder liner outer wall, 6... Piston ring outer circumferential surface 7... Piston ring inner circumferential surface, 8... Engine, 9... Flywheel,
10... Marker, 11... Position detection sensor. Figure 2

Claims (2)

[Claims] (1) Ultrasonic waves are emitted from the outer peripheral surface of the cylinder liner toward the piston ring, and based on the time difference between the reception of the reflected wave reflected by the outer peripheral surface of the piston ring and the reflected wave reflected by the inner peripheral surface of the piston ring. A piston ring wear monitoring method that detects the radial thickness of the piston ring. (2) An ultrasonic power transmitter attached to the outer peripheral surface of the cylinder liner, a detection means for detecting that the sliding piston ring is at the same level as the attachment position of the ultrasonic receiver, and a detection signal from the detection means When the ultrasonic transmitter/receiver transmits an ultrasonic wave, the piston ring is activated based on the time difference between the reception of the reflected wave reflected from the outer circumferential surface of the piston ring and the reflected wave reflected from the inner circumferential surface of the piston ring. A piston ring wear monitoring device comprising calculation means for calculating the radial thickness of the piston ring.