The wave cut is lost as the liner wear is promoted; however, it is considered effective in maintaining the excellent lubrication condition during the adaptability of the ring and liner running surface in the beginning after the navigational service is started.

　

4.2 Effect of oil groove

Regarding the oil groove, there is a time delay before the cylinder oil is filled in the oil groove as described in 3.1 above, and Table 5 shows the comparison of the spread width in the circumferential direction between the wave cut together with the oil groove and only the wave cut setting the cycle at which the cylinder oil is started to spread over the liner running surface as a zero point. The spread width is equal in both cases with the condition of the engine speed of 70 rpm and the oil feed quantity of 0.01 cc/ome feed; otherwise, the spreadability is more excellent with the wave cut together with oil groove by 1.6 to 2.3 times. It is thus concluded that the oil groove are particularly effective in promoting the spreadability in the circumferential direction of the cylinder oil.

　

Table 5 Influence of oil groove on the spread in the circumferential direction

　

5. Conclusion

　

The following results are obtained from this study.

(1) The spreadability of the cylinder oil is more excellent with the wave cut of the liner than with the honing, and in particular, the spreadability in the circumferential direction is more effective. This is considered attributable to the fact that the groove in the circumferential direction of the wave cut promotes the flow of the cylinder oil in the circumferential direction.

(2) The oil groove is also effective in promoting the spreadability in the circumferential direction.

(3) The honing is excellent in the spreadability in the stroke direction while it is inferior to the spreadability in the circumferential direction.

(4) When the number of the oil-feed holes is doubled, the spreadability to the whole liner running surface is improved even when the oil feed quantity per hole is reduced to one half.

(5) The spreadability of the cylinder oil per cycle is worse when the engine speed is higher and the running speed is higher.

This is considered attributable to the fact that the movement of the cylinder oil in the stroke direction becomes dominant when the running speed is high, and the spreadability in the circumferential direction is impeded.

(6) The spreadability with the barrel shaped ring running surface is more excellent than that with the plain shape. This is considered attributable to that fact that a gap formed between the curvature of the barrel and the liner surface is effective to the spreadability of the cylinder oil in the circumferential direction.

　

References

1) Furuhamas. S., Trance of JSME (in Japanese), 24-148 (1958), 1032.

2) Wakuri. Y., et al.,Trance of JSME (in Japanese), 43-370(1977), 2319.

3) Brown, S. R. and Hamilton, G. M., J. Mech. Engr. Sci., 19-2 (1977), 81.

4) Dowson, D., et al., Proc. R. Soc. Lond., A 386 (1983), 409.

5) Sanda, S. and Someya, T., Trance of JSME (in Japanese), 55-516 (1989), 2175.

6) Grice, N., et al., SAE Paper 920056 (1992)

7) Hamatake, T., et al., Report of Dept. of Mech. Engr., Oita Univ. (in Japanese), 28(1993), 9.

8) Furuhama, S.,Bull.JSME (1961), 744

9) Hamilton, G. M. and Moore, S. L., Proc. Instn. Mech. Engr., 188 (1974), 253

10) Shaw, B. T., et al., SAE Paper 920615 (1992)

11) Moore, S. L., CIMAC, D04 (1993)

12) MESJ Committee of Lubricant, MESJ (in Japanese), 6-11 (1971), 881.

13) Mitsutake. S. and Takahashi, F., Mitsubishi Juko Giho (in Japanese), 16-2 (1979), 168.

14) S. Sabun, et al., Proc. JSLE 31th Conference (in Japanese), (1986), 29.

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