Variable valve mechanism of internal combustion engine

Patent metadata

Field	Value
Publication number	US-10167745-B2
Application number	US-201715419836-A
Country	US
Kind code	B2
Filing date	Jan 30, 2017
Priority date	Mar 18, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A variable valve mechanism of an internal combustion engine includes an outer arm, an inner arm, a switching device that switches between a coupled state and a non-coupled state, and a lost motion spring. The lost motion spring has an extending portion extending from the outside of the space to the inside of the space. The extending portion has a contact portion that is in contact with the inner arm in the space and being configured to swing in conjunction with swinging of the inner arm. A through-hole is formed in a vertically intermediate portion of the outer arm such that connecting portions are provided at vertically opposite sides of the through-hole, and a portion of the extending portion, a swinging amount of which is smaller than that of the contact portion, passes through the through-hole that allows the portion to swing therein.

First claim

The invention claimed is:

1. A variable valve mechanism of an internal combustion engine, the variable valve mechanism comprising:
an outer arm that drives a valve when being swung and has a space formed in an intermediate portion thereof in a width direction;
an inner arm that is swingably provided in the space and is driven by a cam to swing;
a switching device that switches between a coupled state in which the inner arm and the outer arm are coupled so as to integrally swing and a non-coupled state in which the coupled state is released; and
a lost motion spring that biases the inner arm toward the cam in the non-coupled state,
wherein the lost motion spring has an extending portion extending from an outside of the space to an inside of the space, the extending portion having a contact portion that is in contact with the inner arm in the space and being configured to swing in conjunction with swinging of the inner arm, and
wherein a through-hole is formed in a vertically intermediate portion of the outer arm such that connecting portions are provided at vertically opposite sides of the through-hole, and a portion of the extending portion, a swinging amount of which is smaller than that of the contact portion, passes through the through-hole that allows the portion of the extending portion to swing therein.

2. The variable valve mechanism of an internal combustion engine according to claim 1 , wherein the lost motion spring has a coil portion disposed outside the space and the extending portion extending from the coil portion to the inside of the space, and
wherein, in the extending portion, a length from a base end of the extending portion through the through-hole to a position adjacent to the space is equal to or shorter than 50% of a length from the base end to a position at the contact portion.

3. The variable valve mechanism of an internal combustion engine according to claim 2 , wherein an accommodating portion that accommodates the coil portion is formed in the outer arm, part of the accommodating portion communicates with the space, and a communicating part forms the through-hole.

4. The variable valve mechanism of an internal combustion engine according to claim 2 , wherein the outer arm includes right and left side-plate portions and a base portion that connects rear ends of the right and left side-plate portions to each other,
wherein a left accommodating portion that accommodates a left coil portion is formed in a portion between the left side-plate portion and the base portion,
wherein a right accommodating portion that accommodates a right coil portion is formed in a portion between the right side-plate portion and the base portion, and
wherein a front side of each of the right and left accommodating portions partly communicates with the space, and communicating parts form the through-holes.

5. The variable valve mechanism of an internal combustion engine according to claim 1 , wherein a roller that is in contact with the cam is rotatably attached to the inner arm via a roller shaft and a bearing, and the contact portion is in contact with an engaging protrusion that is formed on an end portion of the roller shaft.

Assignees

• Otics Corp

Inventors

• Suzuki Hiroyuki
• Sugiura Akira

Classifications

• F01L2305/00

  Valve arrangements comprising rollers · CPC title

• F01L2001/467

  Lost motion springs · CPC title

• F01L1/185 Primary

  Overhead end-pivot rocking arms · CPC title

• F01L2001/186

  Split rocking arms, e.g. rocker arms having two articulated parts and means for varying the relative position of these parts or for selectively connecting the parts to move in unison · CPC title

• F01L2820/02

  Formulas · CPC title