| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of a harmful impact wave in a nozzle situated downstream as a low pressure region is insured in the vicinity of the tip of a poppet valve and to provide a poppet valve device which is to be increased in a thrust factor, having high efficiency. SOLUTION: By the pressure difference between two chambers fronting on the upper and surface and the under surface of a poppet valve, the tip seat part of the poppet valve is removably mounted on a valve seat to open and close a gas passage. In a so formed poppet valve device, the poppet valve has the tip seat part the end part of which is formed into a reduced conical shape, and its seat surface is formed in a conical surface along the shape of the tip seat part. The passage area of a choke part formed between the conical surface and a gas passage situated downstream is decreased to a value lower than the area of a passage between the tip seat part and the seat surface during a maximum lift of the poppet valve. Furthermore, the tip seat part of the poppet valve is formed such that a tip position, when the poppet valve is lifted is positioned in a level above that of the choke part.
|
