JPH0617853B2 - Cylinder lubrication evaluation device for piston engine - Google Patents

Description

The present invention relates to a reciprocating or rotating piston engine (internal combustion engine,
Cylinder lubrication evaluation device for evaluating the lubrication state of cylinders and pistons and piston cylinders in compressors and the like.

[Conventional technology]

In order to determine the lubrication state of the cylinder, piston and piston ring of a diesel engine, the temperature is measured by a thermocouple conventionally embedded in the cylinder liner, the lubrication state of the sliding surface is determined from the change in the liner temperature, and the operating conditions are controlled. By controlling the amount of lubricating oil supply, we have prevented the occurrence of serious accidents and failures.

By the way, in the case of this method, the temperature generally has poor responsiveness and changes due to changes in engine load and the like, and therefore there is no sensitivity for judging the quality of the boundary lubrication state between the cylinder liner and the piston ring or the magnitude of wear. For this reason,
It is difficult to evaluate the amount of wear, the amount of lubricating oil, and the appropriateness with the above conventional methods.

Therefore, in order to solve these problems and evaluate the lubrication condition of the sliding surface, the distance between the sliding surfaces of the cylinder liner and the piston cylinder (or the oil film thickness), the degree of contact, etc., can be determined by an ultrasonic transmitter / receiver. There is a way to evaluate.

FIG. 2 shows this system, and FIG. 3 shows an enlarged view of the relationship between the transmitter / receiver and the sliding surface.

Here, 1 is a piston body, 2 is a piston ring, 3 is a cylinder liner, 4 is a cylinder cover, 5 is an exhaust valve, 6
Indicates a fuel valve, and an ultrasonic wave transmitter 71 is attached to the outer peripheral surface of the cylinder liner 3, and a synchronizing device 73 for controlling pulse generation timing controls the crank angle signal 74 at an appropriate timing to generate an ultrasonic pulse. The ultrasonic wave I ₀ is transmitted from the transmitting circuit 72 toward the inner surface (sliding surface) of the cylinder liner by the harmonic wave transmitter 71. On the other hand, reference numeral 81 denotes a receiver of the reflected ultrasonic waves R ₁ , R ₂ , and R ₃ , the signal received by this is amplified by the receiving circuit 82, and the ultrasonic signal waveform is displayed on the display unit 83. . FIG. 3 schematically shows the reflection and transmission of this ultrasonic wave on the sliding surface and the reflection on the back surface of the piston ring 2.

Here, when the ultrasonic wave is pulsed by the synchronizing device 73 from the transmitter 71 at the time of passing through the ring, the ultrasonic wave I ₀ passes through the cylinder liner 3 and slides the piston ring 2 which is just passing. To the surface. At this time, (i) If there is an oil film between the cylinder liner 3 and the piston ring 2, part of the ultrasonic waves will be reflected from the sliding surface of the cylinder liner 3 and part of the ultrasonic wave will pass through the oil film part and It is reflected by the sliding surface and the back surface of the ring 2 and returns to the wave receiver 81 through the oil film portion again.

(ii) If there is no oil film between the cylinder liner 3 and the piston ring 2, the ultrasonic wave will only be reflected from the sliding surface of the cylinder liner 3 and will not propagate to the piston ring 2 portion. Receives only the reflected waves R ₁ , R ₂ from the sliding surface of the cylinder liner 3 as the reflected waves R ₁ , R ₂ , R ₃ .

Therefore, according to this method, the reflected waves R ₁ , R ₂ ,
Based on the pattern of R ₃ and the height of its reflected wave, it is possible to evaluate whether or not there is a lubricating oil film, and further to reduce and optimize the amount of lubricating oil.

[Problems to be solved by the invention]

As described above, it is possible to evaluate the lubrication state of the sliding surface by the method of transmitting and receiving ultrasonic waves, but when the ultrasonic wave transmitters / receivers 71, 81 are attached to the outer peripheral surface of the cylinder liner 3, There is such a problem.

Generally, cast iron is used as the material of the cylinder liner 3 in terms of wear resistance and lubricity. The cast iron crystal structure contains many fine reflection sources, and the ultrasonic wave transmission is very poor, and in many cases it is non-uniform, so the ultrasonic wave detection accuracy is extremely poor. Be seen. This situation is shown in FIG. 4, in which (a) shows the cylinder liner 3 as a normal defect-free steel material such as SS material or SC material (S45
C) is used, and (b) shows a case where cast iron, for example, FC25 is used as the cylinder liner 3. By comparing these figures, the ultrasonic transducer on the outer peripheral surface of the cast iron cylinder liner is shown. It can be seen that it is difficult to evaluate the lubrication state of the sliding surface when is attached.

Therefore, it is an object of the present invention to provide a cylinder lubrication evaluation device for a piston engine, which can evaluate the sliding state of a cast iron cylinder liner and a piston cylinder having wear resistance and lubricity during actual operation.

[Means for solving problems]

In order to achieve the above object, the present invention mounts an ultrasonic wave transmitter / receiver in a cylinder liner, and this ultrasonic wave propagates toward the cylinder liner sliding surface and is reflected back from the liner sliding surface and the ring back surface. It is characterized in that the part of the incoming path is made of a material with good ultrasonic permeability, this part is inserted and fixed in a cast iron cylinder liner and molded and processed as an integrated cylinder liner. .

[Action]

With the cylinder liner configured as described above, (1) the ultrasonic transmission of the liner portion to which the ultrasonic transmitter / receiver is attached is improved, and the ultrasonic detection accuracy is improved.
The lubrication state of the sliding surface can be evaluated by the method described above.

(2) Since other liner parts are cast iron, wear resistance,
Lubricity is secured.

〔Example〕

The present invention will be described below with reference to FIG. In the present invention, the method for evaluating the cylinder lubrication state is the same as the system by the transmission and reception of ultrasonic waves described in [Prior Art], but the ultrasonic transmission of the ultrasonic transmission path is improved. In FIG. 1, reference numerals 2, 3, 71 and 81 are the same as those described above. The difference is that the cylinder liner 3 made of cast iron has a material with good ultrasonic permeability (for example, S45C).
Steel material 31 is inserted and fixed to form and process as an integrated cylinder liner.

Since the cylinder liner 3 is configured as described above, the following effects can be obtained.

(1) Cylinder liner 3 with ultrasonic wave transmitter / receiver 71 attached
Since the ultrasonic transmission of the part becomes good and the detection accuracy of the ultrasonic wave is improved, the lubrication state of the sliding surface can be evaluated by the above method.

(2) Since the other 3 parts of the cylinder liner are cast iron, wear resistance and lubricity are secured.

In this case, if the shape of 31 is tapered as shown in the figure, the influence of delayed echo reflected from the outer peripheral surface of 31 and returning can be reduced, and accuracy can be improved.

[Effects of the Invention] According to the present invention described above, the sliding state between the cast iron cylinder liner and the piston ring, which have wear resistance and lubricity, can be evaluated during actual operation, so that the piston / cylinder lubrication of the reciprocating piston engine can be evaluated. It is possible to provide a cylinder lubrication evaluation device for a piston engine, which can improve reliability and can reduce and optimize the supply amount of lubricating oil.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of the vicinity of a cylinder liner showing an embodiment of the present invention, FIG. 2 is a block diagram showing an example of a conventional lubrication evaluation apparatus by ultrasonic wave transmission / reception, and FIG. 3 is an ultrasonic wave transducer. Diagram showing the state of reflection and passage of ultrasonic waves in the attached liner, sliding surface, and ring. Fig. 4 shows the difference in ultrasonic permeability when the cylinder liner is made of steel or cast iron. It is a figure. 3 ... Cylinder liner, 31 ... Material with good ultrasonic permeability, 71 ... Transmitter, 81 ... Receiver.

Claims (1)

[Claims] 1. An ultrasonic wave transmitting / receiving device is attached to a position corresponding to a piston ring sliding range on an outer peripheral surface of a cylinder of a reciprocating piston engine, and an ultrasonic wave is generated to oscillate in a pulse shape at a time corresponding to a piston ring passing position. In the device that evaluates the lubrication state of the cylinder and piston ring, which is transmitted by the device and its generation timing control device, received and amplified, and displayed, in this cylinder liner, an ultrasonic wave transmitter / receiver is attached. The part of the transmission path that propagates toward the cylinder liner and returns after being reflected is composed of a material with good ultrasonic permeability such as steel, and this part is inserted and fixed in the cast iron cylinder liner. Cylinder lubrication evaluation device for piston engines, characterized by being molded and processed as an integrated cylinder liner.