Engine

Patent metadata

Field	Value
Publication number	US-11655751-B1
Application number	US-202217989975-A
Country	US
Kind code	B1
Filing date	Nov 18, 2022
Priority date	Dec 6, 2021
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

To effectively suppress strong knock that occurs in the operating region of high load and high rotation in a specific engine having a pre-chamber in a combustion chamber, the engine includes a piston that defines a combustion chamber together with a cylinder block and a cylinder head. The combustion chamber includes a sub-chamber and a main chamber separated from the sub-chamber by a pre-chamber. The specific ratio obtained by dividing a volume of the sub-chamber by a stroke volume of a cylinder is greater than or equal to 0.00005 and less than or equal to 0.00045.

First claim

The invention claimed is:

1. An engine comprising:
a cylinder block in which a cylinder is formed;
a cylinder head assembled onto the cylinder block to cover a top of the cylinder;
a piston provided so as to reciprocate inside the cylinder, the piston defining a combustion chamber together with the cylinder block and the cylinder head; and
a spark plug that performs ignition in the combustion chamber,
wherein the combustion chamber includes a sub-chamber that houses an electrode of the spark plug, and a main chamber separated from the sub-chamber by a partition wall having a through-hole, the main chamber having a volume larger than a volume of the pre-chamber, and
wherein a specific ratio obtained by dividing a volume of the sub-chamber by a stroke volume of the cylinder is greater than or equal to 0.00005 and less than or equal to 0.00045.

2. The engine according to claim 1 ,
wherein the specific ratio is greater than or equal to 0.00013 and less than or equal to 0.00035.

3. The engine according to claim 2 ,
wherein a bore/stroke ratio is set to greater than or equal to 1 and less than or equal 1.5.

4. The engine according to claim 3 ,
wherein a compression ratio of the engine is greater than or equal 14 and less than or equal to 25.

5. The engine according to claim 4 , further comprising:
an injector that injects fuel into the main chamber,
wherein an air-fuel mixture in the sub-chamber is generated by causing the fuel injected by the injector to flow into the sub-chamber through the through-hole.

6. The engine according to claim 5 ,
wherein the injector injects liquid fuel.

7. The engine according to claim 6 ,
wherein the through-hole is one of four to six through-holes that are formed in the partition wall so as to be arranged at intervals in a circumferential direction around the electrode of the spark plug.

8. The engine according to claim 2 ,
wherein a bore/stroke ratio is set to greater than or equal to 1 and less than or equal 1.5.

9. The engine according to claim 3 ,
wherein a compression ratio of the engine is greater than or equal 14 and less than or equal to 25.

10. The engine according to claim 3 ,
wherein a compression ratio of the engine is greater than or equal 14 and less than or equal to 25.

11. The engine according to claim 4 , further comprising:
an injector that injects fuel into the main chamber,
wherein an air-fuel mixture in the sub-chamber is generated by causing the fuel injected by the injector to flow into the sub-chamber through the through-hole.

12. The engine according to claim 4 , further comprising:
an injector that injects fuel into the main chamber,
wherein an air-fuel mixture in the sub-chamber is generated by causing the fuel injected by the injector to flow into the sub-chamber through the through-hole.

13. The engine according to claim 4 , further comprising:
an injector that injects fuel into the main chamber,
wherein an air-fuel mixture in the sub-chamber is generated by causing the fuel injected by the injector to flow into the sub-chamber through the through-hole.

Assignees

• Mazda Motor

Inventors

• Harada Yuji
• Uchida Kenji
• Ono Ryohei
• Kidokoro Masayuki
• Nagatsu Kazuhiro

Classifications

• F02B23/08

  with positive ignition · CPC title

• F02B19/18

  Transfer passages between chamber and cylinder · CPC title

• F02B19/12 Primary

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title

• F02B19/108

  with fuel injection at least into pre-combustion chamber, i.e. injector mounted directly in the pre-combustion chamber · CPC title

• F02B19/1023

  pre-combustion chamber and cylinder being fed with fuel-air mixture(s) · CPC title