FUEL INJECTION STRATEGIES IN OPPOSED-PISTON ENGINES WITH MULTIPLE FUEL INJECTORS

• US 20180371989A1
• Filed: 08/31/2018
• Published: 12/27/2018
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Achates Power, Inc.
• Original Assignee: Achates Power, Inc.
• Inventors: KLYZA, CLARK A., REDON, FABIEN G.
• Granted Patent: US 10,458,327 B2
• Time in Patent Office: Days
• CPC Class Codes: F02B 75/282 the pistons having equal strokes
• CPC Class Codes: F02D 41/3094 the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: F02D 41/403 with pilot injections
• CPC Class Codes: F02D 41/405 with post injections
• CPC Class Codes: F02M 55/025 Common rails
• CPC Class Codes: F02M 69/04 Injectors peculiar thereto
• CPC Class Codes: F02M 69/045 for injecting into the combustion chamber F02M69/046 takes precedence
• CPC Class Codes: F02M 69/10 peculiar to scavenged two-stroke engines, e.g. injecting into crankcase-pump chamber
• CPC Class Codes: F02M 69/465 of fuel rails
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

Claims

1. A fuel injection means for injecting fuel in an opposed-piston engine, including first and second fuel injectors for direct side injection of fuel into a combustion chamber defined between end surfaces of a pair of opposed pistons as the pistons approach top dead center locations in a cylinder of the opposed-piston engine, control means responsive to engine operating conditions for generating fuel injection control signals;

and,

an injector driver responsive to the fuel injection control signals for generating fuel injector actuation signals operative to cause a first fuel injector to emit a first split injection and to cause a second fuel injector to emit a second split injection independently of the first injector;

wherein the fuel injector control signals impose a minimum time interval separating each pilot injection from its following main injection.

2. The fuel injection means of claim 1, wherein each of the first and second split injections includes a pilot injection separated in time from a following main injection by at least a minimum interval.

3. The fuel injection means of claim 2, wherein the first and second split injections overlap.

4. The fuel injection means of claim 2, wherein the pilot injection of the first split injection is offset from the pilot injection of the second split injection by an amount of time less than the minimum interval.

5. The fuel injection means of claim 1, wherein the injector driver is further responsive to the fuel injection control signals for causing each of the first and second fuel injectors to emit a single injection.

12. The fuel injection system of claim 1, wherein each of the first and second split injections includes a pilot injection separated in time from a following main injection by at least a minimum interval.

13. The fuel injection system of claim 12, wherein the first and second split injections overlap.

14. The fuel injection system of claim 12, wherein the pilot injection of the first split injection is offset from the pilot injection of the second split injection by an amount of time less than the minimum interval.

6. An opposed-piston engine, comprising:

at least one cylinder with a pair of pistons disposed in opposition for movement between top and bottom dead center positions therein;

a plurality of fuel injectors positioned for direct side injection of fuel into the cylinder when a combustion chamber is defined between end surfaces of the pistons as the pistons approach the top dead center locations;

a control means responsive to engine operating conditions for generating fuel injection control signals when the pistons are near top dead center locations in the cylinder; and

,

an injector driver responsive to first control signals for generating first fuel injector actuation signals operative to cause a single fuel injector to inject fuel into the cylinder and for generating second fuel injector actuation signals operative to cause at least two fuel injectors to inject fuel into the cylinder.

7. The opposed-piston engine of claim 6, wherein the first fuel injector actuation signals are further operative to cause the single fuel injector to inject fuel into the cylinder by a split injection.

8. The opposed-piston engine of claim 6, wherein the second fuel injector actuation signals are further operative to cause each fuel injector to inject fuel into the cylinder by a split injection.

9. he opposed-piston engine of claim 6, wherein the second fuel injector actuation signals are further operative to actuate the at least two injectors sequentially.

10. The opposed-piston engine of claim 6, wherein the second fuel injector actuation signals are further operative to actuate the at least two injectors simultaneously.

11. A fuel injection system for an opposed-piston engine, comprising:

first and second fuel injectors for direct side injection of fuel through a sidewall of a cylinder of the engine into a combustion chamber defined in the cylinder between end surfaces of a pair of opposed pistons as the pistons approach top dead center locations in the cylinder;

a control unit responsive to engine operating conditions for generating fuel injection control signals; and

,

an injector driver responsive to the fuel injection control signals for generating fuel injector actuation signals operative to cause a first fuel injector to emit a first split injection and to cause a second fuel injector to emit a second split injection independently of the first injector;

wherein the fuel injector control signals impose a minimum time interval separating each pilot injection from its following main injection.

15. The fuel injection system of claim 11, wherein the injector driver is further responsive to the fuel injection control signals for causing each of the first and second fuel injectors to emit a single injection.