Patent TW-201529957-A (TW)
Title: Pressure relief device of internal combustion engine
Inventor: YANG SI-DAI
IPC: F01L13/08
Filed: 2014-01-29
Abstract: The present invention relates to a pressure relief device of an internal combustion engine. The pressure relief device is assembled on a camshaft. The camshaft comprises an intake cam and an exhaust cam. The end of camshaft at the exhaust cam is configured with a receiving groove. The side of exhaust cam at the receiving groove is configured with a pivoting hole. The pressure relief device comprises a base plate, a counterweight swing arm, an elastic element, a pressure relief camshaft and a shaft rod. The base plate is disposed on the camshaft adjacent to the exhaust cam, and is configured with a shaft hole. The opposite end of the shaft hole is configured with a position-limiting hole. The two ends between the shaft hole and the position-limiting hole are respectively configured with a through hole and an engaging groove. One end of the counterweight swing arm is configured with a pivot hole, and the pivot hole is corresponded to the shaft hole of the base plate. The side of the counterweight swing arm near the pivot hole is configured with a hook hole. The counterweight swing arm is configured with a notch. Another end of the counterweight swing arm at the pivot hole is configured with a position-limiting bump protruded outwardly. One end of the position-limiting bump may be slidably inserted within the position-limiting hole of the base plate. One end of the elastic element is hooked on the engaging groove of the base plate, and another end is hooked in the hook hole of the counterweight swing arm. The pressure relief camshaft is received within the receiving groove of the camshaft and is penetrated through the through hole of the base plate. The pressure relief camshaft comprises a base portion. A cam portion is extended from the base portion toward the direction of the exhaust cam. One side of the cam portion is an arc surface, and another side is a flat surface. The edge of the cam portion is extended with a pivot portion. One end of the pivot portion is inserted into the pivoting hole of the exhaust cam. The base portion of the pressure relief camshaft is extended with a lever portion on another side of the extended cam portion. One end of the lever portion may be slidably inserted in the notch of the counterweight swing arm. One end of the shaft rod is inserted in the shaft hole of the base plate, and another end is inserted in the pivot hole of the counterweight swing arm. Thus, when the counterweight swing arm is driven by the centrifugal force of camshaft rotation for swinging, the pressure relief camshaft may be driven to rotate within the receiving groove of the camshaft. While being used for the internal combustion engines of different exhaust volumes, it is only required to process and change the radial position of the receiving groove on the camshaft for directly applying the pressure relief device with no need of manufacturing a new pressure relief device, so as to enhance the universality of the pressure relief device and further enhance the effect of the pressure relief device.