Membrane carburetor

Abstract

A membrane carburetor (1) has a control chamber (13) which is connected via at least one fuel opening (9, 10) to an intake channel (3). The control chamber (13) is delimited by a control membrane (14). A fuel line (54) opens into the control chamber (13) via an inlet valve (15). The inlet valve (15) opens in dependence upon the deflection of the control membrane (14). The membrane carburetor (1) has an acceleration pump (30) which is actuated in dependence upon the position of a throttle element held in the intake channel (3). A good acceleration enrichment and a stable running of the internal combustion engine are achieved when the acceleration pump (30) operates hydraulically on at least one actuating member in the control chamber (13).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawings wherein:

FIG. 1 is a section view of a membrane carburetor according to the invention;

FIG. 2 is a schematic of the acceleration pump of the membrane carburetor in the nonactuated position;

FIG. 3 is a schematic of the acceleration pump of FIG. 2 in the actuated position;

FIG. 4 to FIG. 9 show the accelerator pump in the nonactuated position; and,

FIG. 10 is a schematic showing the accelerator pump of FIG. 9 in the actuated position.

Claims

1. A membrane carburetor comprising: a control chamber;an intake channel;at least one fuel opening connecting said control chamber to said intake channel;a deflectable control membrane delimiting said control chamber;fuel supply means for supplying fuel to said control chamber;said fuel supply means including an inlet valve; and, a fuel line opening into said control chamber via said inlet valve;said control membrane being operatively connected to said inlet valve so as to open said inlet valve in dependence upon deflections of said control membrane;a throttle element mounted in said intake channel so as to be moveable in position;an accelerator pump operatively connected to said throttle flap so as to be actuated in dependence upon the position of said throttle flap;said control chamber having an actuating member disposed therein; and,said accelerator pump being hydraulically connected to said actuating member so as to permit said accelerator pump to act hydraulically on said actuating member.

2. The membrane carburetor of claim 1, said accelerator pump including an enclosure defining a pump chamber; a pump piston delimiting said pump chamber; and, a pressure line leading from said pump chamber and said accelerator pump acting on said actuating member via said pressure line.

3. The membrane carburetor of claim 2, further comprising: a scavenging pump;a suction line connecting said pump chamber to said scavenging pump; and,said suction line opening into said pump chamber at a location thereof whereat said suction line is closed by said pump piston when said pump piston is actuated.

4. The membrane carburetor of claim 2, wherein said suction line is a first suction line; and, wherein said membrane carburetor further comprises a second suction line opening into said pump chamber and connecting said pump chamber to said control chamber; and, a check valve mounted in said second suction line so as to open in flow direction to said pump chamber.

5. The membrane carburetor of claim 4, further comprising a check valve mounted in said pressure line so as to open in flow direction from said pump chamber.

6. The membrane carburetor of claim 1, wherein said actuating member is said inlet valve.

7. The membrane carburetor of claim 6, wherein said inlet valve is opened by said accelerator pump when there is acceleration.

8. The membrane carburetor of claim 6, wherein said inlet valve is closed by said accelerator pump when there is deceleration.

9. The membrane carburetor of claim 1, wherein said actuating member is said control membrane.

10. The membrane carburetor of claim 1, further comprising a lever mounted in said control chamber for coupling the position of said inlet valve to the position of said control membrane; and, said lever being said actuating member and said accelerator pump acting on said lever.

11. The membrane carburetor of claim 10, wherein said lever is pivotally mounted in said control chamber and said control membrane is coupled in both pivot directions to the movement of said lever.

12. The membrane carburetor of claim 11, wherein said control membrane is coupled with play to the movement of said lever.

13. The membrane carburetor of claim 3, wherein said pressure line is connected to said control chamber via a throttle element.

14. The membrane carburetor of claim 2, further comprising: an enclosure defining a pressure space and said pressure line opening into said pressure space; and, an actuating piston delimiting said pressure space; and, said actuating piston being operatively coupled to said actuating member for actuating said actuating member.

15. The membrane carburetor of claim 14, wherein said throttle element is configured as a relief bore in said actuating piston.

16. The membrane carburetor of claim 14, further comprising a lever mounted in said control chamber for coupling the position of said inlet valve to the position of said control membrane; and, said actuating piston being operatively connected to said lever for acting thereon.

17. The membrane carburetor of claim 16, wherein said actuating piston is connected to said lever via a fixation which transmits a stroke of said actuating piston in both directions to said lever.

18. The membrane carburetor of claim 2, wherein said control chamber comprises a nozzle and said pressure line opens into said control chamber via said nozzle for supplying a fluid jet into said control chamber for actuating said actuating member.

19. The membrane carburetor of claim 18, further comprising a lever mounted in said control chamber for coupling the position of said inlet valve to the position of said control membrane; and, said fluid jet acting on said lever; and, said lever having a spoon-shaped section formed thereon and said spoon-shaped section being disposed to overlap the nozzle opening of said nozzle.

20. The membrane carburetor of claim 1, said inlet valve including a valve body and a valve seat coacting with said valve body for opening and closing said inlet valve; and, said inlet valve further including a control body tightly connected to said valve body.

21. The membrane carburetor of claim 20, said accelerator pump including an enclosure defining a pump chamber; a pump piston delimiting said pump chamber; and, a pressure line leading from said pump chamber; and, said membrane carburetor further comprising an enclosure defining a pressure space; said control body being configured as an actuating piston delimiting said pressure space; and, said pressure line opening into said pressure space.

22. The membrane carburetor of claim 20, wherein said control body is configured as a weight body.