Chain for automobile engine

Abstract

The invention provides an automobile engine chain which can restrain a inordinate wear elongation between a pin and a sliding surface of a sleeve caused by a grinding wear even under the condition of using lubricating oil which has occluded foreign substance and extreme deterioration and the high degree of oxidation at the same time, and under the condition of being constructed by the high degree of compatibility, the pin and the sleeve are hard to adhesive caused by the wear of the adhesion is restrained. A Cr carbide lamellae which is formed by a process of diffusion and penetration is carried out in a surface of the pin, the Cr carbide lamellae which is as a steel most lateral of a lateral of a pin base-plate is mainly composed of Cr7C3, the most lateral of the Cr carbide lamellae of the pin is mainly composed of Cr23C6, and forms a surface concave part which has smaller surface pressure and occluded foreign substance which size is equal to carbon gray of the lubricating oil and falls into the most lateral of the Cr carbide lamellae of the pin under the state of remaining the most lateral, therefore, the invention achieves the purpose.

Description

technical field [0001] The present invention relates to a chain for power transmission and a chain for driving a camshaft used in an automobile engine, and particularly preferably to a timing chain for an automobile engine. Background technique [0002] In recent years, in the power transmission medium used in the camshaft drive mechanism of automobile engine, etc., according to the requirements of high load, high speed, improvement of layout freedom and maintenance-free, it replaces the toothed one that has been widely used in the past. Belts and V-belts, metal bush chains and metal roller chains with good durability are increasingly used. [0003] Generally, metal bushing chains for automobile engines are made of steel that press-fit both ends of a cylindrical bushing into the bushing holes of a pair of inner plates, and pass through the bushing with a gap. Both ends of the pin are pressed into the pin holes of a pair of outer plates arranged on the outer sides of a pair ...

AI Technical Summary

Problems solved by technology

[0010] However, in the small-sized chain for transmission of motorcycles and general equipment disclosed in the above-mentioned Patent Document 1, the surface of the pin is subjected to surface hardening treatment such as boronizing treatment or chromizing treatment, or nickel or the like is applied to the surface of the pin. However, when used in timing chains of automobile engines, etc., there are occasional reports of abnormal wear (Abnormal wear) and elongated chains that cannot exhibit expected durability.

[0011] In addition, in the chain for an automobile engine disclosed in the aforementioned Patent Document 2, the material of the sleeve is carburized and vanadium carbide (VC) is formed on the surface of the pin to suppress friction between the sleeve and the pin. Adhesive wear, but requires thermal processing of both the sleeve and the pin and the formation of a vanadium carbide (VC) layer, "increasing manufacturing costs"

[0012] Furthermore, when the surface treatment method for the silent chain disclosed in the aforementioned Patent Document 3 is applied to a roller chain or a bush chain used as a chain for an automobile engine, although the wear mechanism is not determined, it is presumed that the In the chain or sleeve chain, the surface inside the sleeve is corroded by lubricating oil with a high degree of oxidation, and the sliding contact between the pin and the sleeve with high pressure under high load promotes the wear of the sliding contact surface. Get the same effect as when applied in a silent chain

[0013] Also, since the outermost layer of the pin is completely removed by barrel grinding, in the case of application to a roller chain or bush chain in which the inner surface of the bush is in surface contact with the outer surface of the pin, since the wear powder generated by abrasion The so-called "abrasive wear" that further promotes wear as inclusions exist between the pin and the bush becomes the cause of abnormal wear of the sliding contact surface between the pin and the bush, and cannot perform as well as when it is applied to a silent chain The effect of improving the wear resistance of the pin

[0014] Furthermore, when the pin and the sleeve are made of a material with high affinity, such as the same element, it can be seen that the two tend to "stick" and this also becomes a cause of hindering the smooth bending and sliding of the chain for an automobile engine.

Images