Double-sided engagement type silent chain

Abstract

The present invention provides a both-sided engagement type silent chain, restraining the occurrence of cracks to the bottom of an outermost link plate engaged and fixed to a connecting pin, and restraining the concentrated contact abrasion of a pin hole and a connecting pin of an outer link plate disposed rather closer to the outside in the width direction of the chain to improve the fatigue strength of the whole chain. The both-sided engagement type silent chain 100 includes: inner link plates 110a, 110b disposed rather closer to the center in the width direction of the chain with link teeth 111 projected toward the inner peripheral side of the chain; and outer link plates 120a, 120b disposed rather closer to the outside in the width direction of the chain with link teeth 121 projected toward the outer peripheral side of the chain, wherein the pin hole 122 of the outer link plate 120a has an inner peripheral surface covered with a hardening layer made of chrome carbide, and the backheight H2 of the outermost link plate 120b is made higher than the back height H1 of the inner link plates 110a, 110b and the outer link plate 120a.

Description

Technical field [0001] The present invention relates to a silent chain used as a timing chain of an automobile engine, and more particularly to a double-sided meshing silent chain that is not only wound around a crankshaft drive sprocket and an air intake valve arranged on the inner peripheral side of the chain Cam sprocket, cam sprocket for exhaust valve, etc. are also wound on sprocket for driving auxiliary machinery shaft such as an oil pump arranged on the outer peripheral side of the chain to transmit power on both sides of it. Background technique [0002] In the prior art, as a silent chain used in a timing chain of an automobile engine, etc., a double-sided meshing silent chain as described below is known in which not only the sprocket protruding toward the inner circumference of the chain and the sprocket It meshes, and the sprocket protruding toward the outer circumference of the chain on the other side meshes with other sprockets, and the two sprockets are rotated in d...

AI Technical Summary

Problems solved by technology

[0018] In this way, there is a problem that the sprocket teeth St at the portion colliding with the sprocket 521 of the outer link plate 520a adjacent to the guide plate becomes prone to wear, and in order to suppress this wear, the outermost chain must be adjusted. The plate thickness of the plate 520b is thickened, and when the number of outer chain plates is increased, the chain width becomes wider, which is disadvantageous in terms of space.

[0019] Furthermore, when the existing double-sided meshing type silent chain 500 is arranged on the outer side link plates 520a, 520b which are arranged outwardly in the chain width direction, the sprocket S for driving the auxiliary machine shaft such as an oil pump is driven on the outer peripheral side of the chain, and the The number of the inner sprocket plates 510a and 510b arranged at the center in the chain width direction is relatively small, so there is a problem that the bending and sliding loads of the pin holes 522 and the connecting pins 530 of the outer link plate 520a are relatively small. large, so that the contact friction between the pin hole 522 of the outer link plate 520a and the connecting pin 530 becomes larger

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