Precombustion-chamber engine

Patent metadata

Field	Value
Publication number	US-10316733-B2
Application number	US-201615761758-A
Country	US
Kind code	B2
Filing date	Dec 9, 2016
Priority date	Dec 21, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A precombustion-chamber engine includes a cylinder, a cylinder head disposed on a top of the cylinder, and a piston reciprocably disposed within the cylinder. A main combustion chamber is defined between the piston and the cylinder head. The cylinder head includes a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle. The precombustion chamber includes a cylindrical first passage part extending upwardly from the nozzle, a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area, and a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed. Center O of a cross-section, orthogonal to straight line L, of the second passage part is eccentric with respect to straight line L composed of an axis of the first passage part and an extended line of the axis.

First claim

The invention claimed is:

1. A precombustion-chamber engine, comprising:
a cylinder;
a cylinder head disposed on a top of the cylinder; and
a piston reciprocably disposed within the cylinder, the piston and the cylinder head defining a main combustion chamber therebetween,
the cylinder head including a precombustion-chamber forming part which defines a precombustion chamber communicating with the main combustion chamber through a nozzle,
the precombustion chamber including:
a cylindrical first passage part extending upwardly from the nozzle;
a second passage part extending upwardly from the first passage part and having an upwardly-increasing cross-sectional area; and
a cylindrical space part which extends upwardly from the second passage part and in which a spark plug is disposed,

wherein a center O is eccentric with respect to a straight line L, where the straight line L, is composed of an axis of the first passage part and an extended line of the axis, and the center O is a center of a cross-section, orthogonal to the straight line L, of the second passage part,
wherein, the precombustion-chamber engine further comprises an ignition-fuel-gas supply channel for supplying an ignition fuel gas to the precombustion-chamber,
wherein, provided that
a direction A is a direction in which the center O of the cross-section is eccentric with respect to the straight line L, and
a cross-section S is a cross-section of the precombustion chamber, including the straight line L and the direction A,
the second passage part is symmetric across the cross-section S, and
wherein the ignition-fuel-gas supply channel has a supply port disposed on a space-part forming surface which defines the space part, the supply port being situated away from the cross-section S.

2. The precombustion-chamber engine according to claim 1 ,
wherein a second-passage-part forming surface which defines the second passage part is smoothly connected with a first-passage-part forming surface which defines the first passage part and with a space-part forming surface which defines the space part.

3. The precombustion-chamber engine according to claim 1 ,
wherein, provided that
a first line is a part of a second-passage-part forming surface which defines the second passage part on a direction A side across the straight line L in the cross-section S,
a second line is a part of the second-passage-part forming surface on an opposite side to the direction A across the straight line L in the cross-section S,
θ 1 is an angle between the straight line L and a straight line connecting an upper end and a lower end of the first line, and
θ 2 is an angle between the straight line L and a straight line connecting an upper end and a lower end of the second line,
the second-passage-part forming surface is configured to satisfy θ 1 >θ 2 .

4. The precombustion-chamber engine according to claim 3 ,
wherein the second-passage-part-forming surface is configured to satisfy 30°≤θ 1 ≤45°.

5. The precombustion-chamber engine according to claim 3 ,
wherein the first line extends upwardly with increasing a distance from the straight line L, and
wherein the second line includes: an extended line part extending, from a first-passage wall surface which defines the first passage part, in a direction of extending the first-passage wall surface; and a tapered line part connecting the extended line part with a space wall surface which defines the space part and extending upwardly with increasing a distance from the straight line L.

6. The precombustion-chamber engine according to claim 1 , further comprising an ignition-fuel-gas supply channel for supplying an ignition fuel gas to the precombustion chamber,
wherein the ignition-fuel-gas supply channel has a supply port disposed on a space-part forming surface which defines the space part, the supply port being situated on an opposite side to the direction A across the straight line L, and
wherein the ignition-fuel-gas supply channel is configured to inject the ignition fuel gas through the supply port toward a direction A side.

Assignees

• Mitsubishi Heavy Ind Engine & Turbocharger Ltd

Inventors

• Takemoto Daisuke
• Yuuki Akihiro
• Sasaki Shunya
• Ogura Kazuo
• Furukawa Yuta

Classifications

• F02B19/1095

  with more than one pre-combustion chamber (a stepped form of the main combustion chamber above the piston is to be considered as a pre-combustion chamber if this stepped portion is not a squish area) · CPC title

• F02P13/00

  Sparking plugs structurally combined with other parts of internal-combustion engines ({connection of ignition coil to spark plug connector F02P3/02;} with fuel injectors F02M57/06 {; spark plug connector per se H01T13/04 – H01T13/06; predominant aspects of sparking plug, see H01T13/40 – H01T13/44}) · CPC title

• F02B19/08 Primary

  the chamber being of air-swirl type · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• F02B19/1014

  design parameters, e.g. volume, torch passage cross sectional area, length, orientation, or the like · CPC title