CHAIN TENSIONER AND RELIEF VALVE UNIT

摘要

To provide a chain tensioner and a relief valve unit that enable a reduction in the number of parts to be machined and the number of assembling steps, reduce the amount of oil flowing out to the outside, and prevent damage on a check valve, without having to increase the size of the chain tensioner. The chain tensioner includes a check valve unit that suppresses reverse flow of oil flowing into an oil pressure chamber, and a relief valve unit that releases the oil when the pressure inside the oil pressure chamber reaches or exceeds a predetermined high pressure. The check valve unit is disposed as a valve element of the relief valve unit, and the relief valve unit and the check valve unit are formed integral with each other.

主权项

1. A chain tensioner comprising:
a tensioner body that has a cylindrical plunger bore with an open end; a cylindrical plunger that is slidably inserted into the plunger bore; biasing means, accommodated so as to freely expand and contract inside an oil pressure chamber formed between the plunger bore and the plunger, for biasing the plunger in a protruding direction of the plunger; a check valve unit that suppresses reverse flow of oil flowing into the oil pressure chamber; and a relief valve unit that releases the oil when pressure inside the oil pressure chamber reaches or exceeds a predetermined high pressure, the check valve unit being disposed as a valve element of the relief valve unit, and the relief valve unit and the check valve unit being formed integral with each other.