Process for operating a two-stroke internal combustion engine

• US 5,097,811 A
• Filed: 10/02/1990
• Issued: 03/24/1992
• Est. Priority Date: 04/06/1988
• Status: Expired due to Fees

• Current Assignee: Ficht GmbH
• Original Assignee: Ficht GmbH
• Inventors: Baumuller, Andreas
• Primary Examiner(s): ARGENBRIGHT, TONY MICHAEL
• Application Number:
  US07/585,128
• Time in Patent Office: 539 Days
• Field of Search: 123/73 A, 123/73 C, 123/198 F, 123/295, 123/481, 123/305
• US Class Current: 123/481
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 17/005 having direct injection in the combustion chamber
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02B 3/04 Methods of operating
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

When a two-stroke combustion engine (10) runs in the no-load or underload mode with intermittent fuel injection, besides the injection nozzles (12) being activated intermittently, the throttle (18) is opened more than is usual on transition into the no-load or underload mode and the fuel is simultaneously injected at a constant angle of aperture and flow. The process ensures reliable ignition of a weak mixture in the no-load or coasting mode; thus the energy consumption and exhaust production are limited in these modes and the engine runs in a cost-effective manner.

Claims

1. Process for operating a two-stroke combustion engine with an electronically controlled direct fuel injection into the cylinder, wherein the fuel injection in the no-load and the lower underload mode is performed intermittently, characterized in that

the electronic control for the intermittent operation of the injection nozzle additionally opens the throttle beyond the no-load or underload condition in order to supply a larger amount of fresh air, and

the fuel is injected during a load-depending but constant rotational angle with a constant fuel volume flow.

2. Process according to claim 1, characterized in that

the throttle is completely opened in the no-load or the underload mode.

3. Process according to claim 1, characterized in that

the injection of the fuel during a constant rotational angle is controlled by an angle indicator responsive to the crankshaft position.

4. Process according to claim 1, characterized in that

for adjusting a desired engine capacity the rotational angle is changed and then kept constant irrespective of the number of revolutions of said engine.

5. Process according to claim 1, characterized in that

the injection pressure amounts to at least approximately 30 bar.

6. Process according to claim 1, characterized in that

the electronically controlled fuel injection is performed with a duration of each injection in the order of 1 ms.

7. Process according to claim 1, characterized in that

in a two-stroke combustion engine having multiple cylinders the fuel injection for the individual cylinders is performed sequentially and periodically in equal time intervals.