JPS62116141U

JPS62116141U -

Info

Publication number: JPS62116141U
Application number: JP400786U
Authority: JP
Priority date: 1986-01-17
Filing date: 1986-01-17
Publication date: 1987-07-23

Description

[Brief explanation of the drawing]

第１図は本考案の第１実施例に係る圧縮比可変
機関のコネクテイングロツド小端部近傍の縦断面
図であつてロツクピンの係合直前の状態を示した
縦断面図、第２図は第１図の―線に沿う断面
図、第３図は本考案の第２実施例に係る圧縮比可
変機関のコネクテイングロツド小端部近傍の縦断
面図であつてロツクピンの係合直前の状態を示し
た縦断面図、第４図のイは従来の圧縮比可変機関
の全体断面図、第４図のロは第４図のイの偏心ベ
アリング近傍の拡大断面図、である。２１……コネクテイングロツド、２２……ピス
トンピン、２３……偏心ベアリング、２４……ロ
ツク穴、２５……ロツクピン、３０，４０……ロ
ツクピン穴、４１……油通路、２９，４１……ブ
レーキピストン穴、２７，４２……ブレーキピス
トン、３２，４４……ゲート部、３４，４５……
オイル戻し通路、３５，３５ａ，３５ｂ……逆止
弁。 FIG. 1 is a vertical sectional view of the vicinity of the small end of the connecting rod of a variable compression ratio engine according to the first embodiment of the present invention, showing the state immediately before the lock pin is engaged; FIG. 1 is a cross-sectional view taken along line - in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view of the vicinity of the small end of the connecting rod of a variable compression ratio engine according to a second embodiment of the present invention, immediately before engagement of the lock pin. FIG. 4A is an overall sectional view of a conventional variable compression ratio engine, and FIG. 4B is an enlarged sectional view of the vicinity of the eccentric bearing shown in FIG. 4A. 21... Connecting rod, 22... Piston pin, 23... Eccentric bearing, 24... Lock hole, 25... Lock pin, 30, 40... Lock pin hole, 41... Oil passage, 29, 41... Brake piston hole, 27, 42... Brake piston, 32, 44... Gate part, 34, 45...
Oil return passage, 35, 35a, 35b...check valve.

Claims

[Scope of utility model registration request]

An eccentric bearing consisting of a cylindrical body whose inner circumference and outer circumference are eccentric to each other is rotatably interposed between the inner circumference of the small end hole of the connecting rod and the outer circumference of the piston pin. The lock pin, which is slidably and retractably inserted into the lock pin hole provided in the connecting rod, is driven by hydraulic pressure from the oil passage provided in the connecting rod to engage and disengage from the lock hole provided in the eccentric bearing. In a variable compression ratio engine in which the compression ratio is varied by locking or unlocking the rotation of the bearing and changing the relative position of the piston with respect to the connecting rod, a brake is provided on the connecting rod facing the outer peripheral surface of the eccentric bearing. A piston hole is formed, a brake piston that can come into contact with the outer peripheral surface of the eccentric bearing is held in the brake piston hole in a freely removable manner, and the lock pin hole has a
A gate portion is provided between the oil passage and the brake piston, which is opened by the movement of the lock pin when the lock pin is switched to the lock position, and guides the oil in the oil passage to the brake piston hole. A variable compression ratio engine, characterized in that an oil return passage is provided that bypasses the oil and returns the oil to the oil passage, and the oil return passage is provided with a check valve that allows oil to flow in one direction from the brake piston to the oil passage. .