Subchamber type combustion chamber for diesel engine

Patent metadata

Field	Value
Publication number	US-9429066-B2
Application number	US-201313954392-A
Country	US
Kind code	B2
Filing date	Jul 30, 2013
Priority date	Jul 30, 2013
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A subchamber type combustion chamber for a diesel engine, which reduces fuel consumption rate and combustion noise. To achieve the object, a subchamber type combustion chamber is communicated with a main combustion chamber through a nozzle hole, a fuel injection nozzle faces into the subchamber, and a glow plug extends into the subchamber. A heat generating portion of the glow plug includes a rod-shaped portion and a projecting portion projecting from an end of the rod-shaped portion. The projecting portion is provided with a convex curved surface projecting from a circular peripheral edge at the end of the rod-shaped portion while the convex curved surface is reduced in diameter. The percentage of value P/D obtained by dividing projection dimension P of the projecting portion from the end of the rod-shaped portion by diameter dimension D at the end of the rod-shaped portion is 3% to 23%.

First claim

We claim:

1. A subchamber type combustion chamber for a diesel engine in which a subchamber is communicated with a main combustion chamber through a nozzle hole, a fuel injection nozzle faces into the subchamber, and a glow plug extends into the subchamber,
wherein a heat generating portion of the glow plug includes a rod-shaped portion having an end defining a circular peripheral edge and a projecting portion projecting from the end of the rod-shaped portion, the projecting portion having a convex curved surface projecting from the circular peripheral edge of the end of the rod-shaped portion and reducing in diameter therefrom,
wherein the percentage of value P/D obtained by dividing projection dimension P of the projecting portion from the end of the rod-shaped portion by diameter dimension D at the end of the rod-shaped portion is 3% to 23%, and
wherein the percentage of value S 1 /S 2 obtained by dividing surface area S 1 of the projecting portion of the glow plug by surface area S 2 of the subchamber is 0.66% to 1.28%.

2. The subchamber type combustion chamber for a diesel engine according to claim 1 , wherein the percentage of value C/D obtained by dividing extension dimension C of the heat generating portion of the glow plug into the subchamber by diameter dimension D at the end of the rod-shaped portion is 115% to 150%.

3. The subchamber type combustion chamber for a diesel engine according to claim 2 , wherein a compression ratio of the combustion chamber is 22.5 to 25.0.

4. The subchamber type combustion chamber for a diesel engine according to claim 3 , wherein the entire projecting portion of the glow plug provides the convex curved surface.

5. The subchamber type combustion chamber for a diesel engine according to claim 3 , wherein in the projecting portion of the glow plug, an adjacent portion to the rod-shaped portion provides the convex curved surface, and an end has a flat surface.

6. The subchamber type combustion chamber for a diesel engine according to claim 1 , wherein a compression ratio of the combustion chamber is 22.5 to 25.0.

7. The subchamber type combustion chamber for a diesel engine according to claim 6 , wherein the entire projecting portion of the glow plug provides the convex curved surface.

8. The subchamber type combustion chamber for a diesel engine according to claim 6 , wherein in the projecting portion of the glow plug, an adjacent portion to the rod-shaped portion provides the convex curved surface, and an end has a flat surface.

9. The subchamber type combustion chamber for a diesel engine according to claim 1 , wherein in the projecting portion of the glow plug, an adjacent portion to the rod-shaped portion provides the convex curved surface, and an end has a flat surface.

Assignees

• Kubota Kk

Inventors

• Kuwayama Hiroki
• Yamazaki Takahiro
• Ishigaki Yutaka
• Koyama Hideyuki
• Miyazaki Manabu
• Ikemachi Katsunori
• Tanaka Yoshinori

Classifications

• F02B19/1009

  heating, cooling · CPC title

• F02B19/14 Primary

  with compression ignition · CPC title

• F02B17/005

  having direct injection in the combustion chamber · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• F02B19/10

  with fuel introduced partly into pre-combustion chamber, and partly into cylinder · CPC title