Compression ratio variable device for internal combustion engine

Abstract

Abstract PURPOSE: To improve the extent of responsiveness to variable control from a high compression ratio state to the low compression ratio by making pressure oin of an upper liquid chamber in a piston speedily dischargeable at a time when high pressure combustion pressure acts on top of the outer piston externally fitted in an inner piston where a connecting rod is connected. CONSTITUTION: An inner piston 29, where a connecting rod 24 is connected, is fitted in the outer piston of 21 screwed with an annulus 22 on the lower inner circumference via a piston pin 23. And, with upward movement of this outer piston 21, an upper liquid chamber 31 is formed in space between the said piston 21 and the inner piston 29, and also with the downward movement, a lower liquid chamber is made so s to be formed in space between the annulus 22 and the inner piston 29. In the piston pin 23, there is fitted with a spool valve 26 which is slidden in an working liquid chamber 25 in the inner part, whereby a feed passage 35 and a discharge passage 36 are made so as to be selectable, and this spool valve 26 is made so as to be moved in an opening direction of the discharge passage 36 according to hydraulic pressure of the upper liquid chamber 31 to be transmitted through a pressure passage 37. COPYRIGHT: (C)1989,JPO&Japio

Inventors

• 👤 Seiji Suga
• 👤 Tatsuyuki Matsuya
• 👤 Seinosuke Hara
• 👤 Hiromichi Bito
• 👤 Takayuki Arai

Bibliographic Details