IL41922A

IL41922A - Supercharged internal combustion engines

Info

Publication number: IL41922A
Application number: IL41922A
Authority: IL
Inventors: J Melchior
Original assignee: France Etat
Priority date: 1972-04-06
Filing date: 1973-03-30
Publication date: 1976-03-31
Also published as: BR7302471D0; NL7304457A; DK140443C; JPS5874829A; NO143816B; HK43177A; NO143816C; FI55561C; DK143518B; IL41922A0; AU462539B2; YU89673A; HU168199B; CA990160A; CH565940A5; DD103300A5; GB1429493A; ES413178A1; IN138616B; JPS522041B2

Claims

41922/3: WHA WE CLAIM IS :

1. A power unit comprising an internal combustion engine supercharged by a turbine-compressor unit v:hose turbine has an inlet connected to the exhaust of the engine and comprising a by-pass conduit permanently open in operation, communicating with the outlet of the compressor and with the turbine inlet for the engine to be in parallel air flow relation with the by-pass, said by-pass having automatically controlled throttle means to develop a pressure drop in the air flow passing through the by-pass which is substantially independent of the rate of flow traversing said by-pass and which is an increasing function of the pressure existing at the compressor outlet. · ■ ' '

2. A power unit according to claim 1, wherein the increasing function is a linear or substantially linear function.

3. A power unit comprising an internal combustion engine supercharged by a turbine-compressor unit whose compressor operates close to its surge line and whose turbine is connected to receive the exhaust gas of the engine and an air flow delivered by the compressor and which has circulated along a conduit permanently open in operation and by-passing the engine, the pressure drop of said air flow · being an increasing function of the pressure delivered by the compressor. 41922/3

4. A power unit according to claim 2, having automatically controlled throttle means in said by-pass conduit to develop said pressure drop.

5. A power unit according to claim 1, 2 or 4, wherein the throttle means comprises a movable throttle member which limits in said by-pass conduit a throttled . section whose cross-sectional area is determined by the position of said movable member and wherein 'the throttling action of said member tends to increase responsive to increase of the pressure which prevails at a point of the by-pass located upstream of said throttled section and to decrease v/hen the difference between, the pressures which prevail at points of the by-pass located upstream and downstream of said throe Lied section decreases.

6. A power unit according to claim 1, 2 or 4, wherein the throttle means comprises a movable throttle member which limits a throttled section in said by-pass conduit and said movable member is controlled by pressure forces exerted on surfaces which are subjected to the pressures which prevail in said by-pass conduit upstream and downstream of said throttled section, the resultant surface which is subjected to the pressure which prevails upstream of the throttled section being smaller than the - resultant surface subjected to the pressure which prevails donwstrea of the throttled section. 41922/:?

7. A power unit according to claim 1, 2 or 4, wherein the throttle means comprises a throttle member movable within the by-pass conduit and cooperating with a fixed seat for limiting a throttled air flow section of variable effective cross-sectional area.

8. A power unit according to claim 5, 6 or 7, v/herein said throttle member is oparatively connected to a balancing piston which is subjected to the pressure which prevails at a point of the by-pass conduit. '■■

9. A power unit according to anyone of claims 5 to 8, having resilient return means associated with said throttle member and which maintains the throttle means in open condition when atmospheric pressure prevails in the by-pass conduit on both sides of the throttled section.

10. A power uni according to claim 9, wherein said resilient return means is adjustable.

11. A power unit according to anyone of claims 1, 2 and 4-10, wherein said throttle means is provided v/ith viscous damping means.

12. A power uni according to any one of claims 1 to 11, having an auxiliary combustion chamber connected to receive air which has passed through the by-pass conduit and having its outlet connected to the inlet ■ . '.· , ..' , 41922/3

13. A power unit according to claim 12, wherein said auxiliary combustion chamber has a fuel inlet, a ^primary- air intake connected to receive fresh air derived from a point of said by-pass located upstream of said throttling means for combustion of the fuel injected into said auxiliary combustion chamber and a secondary air intake adapted to receive air from said by-pass conduit through throttling means providing said pressure drop. s

14. A power unit according to claim .13, having means for adjusting the flow rate of the primary air which is responsive to the pressure which prevails at a point of the by-pass conduit which is located upstream or downs 'cream o the throttling means.

15. A power unit according to claim 14, wherein said adjusting means comprises a f rst member and a second member movable with respect to each other to adjust the effective cross-sectional area of a passage for said primary air, the first member of the adjusting means being operatively connected to a movable throttle member Of said throttle means and the second member of said adjusting means being controlled by the pressure which prevails downstream of said throttle means.

16. A power unit according to claim 15, wherein said second member of the primary air adjusting means 41922/3 member of said primary air adjusting means which is fast with the movable member of the throttling means.

17. A power unit according to claim 16, wherein said first member of the primary air adjusting means comprises a tube having a first opening in its wall and wherein said second member is a tubular slide valve consisting of a blind tube formed with a second opening adapted to cooperate with said first opening and slidably received in said tube.

18. A power unit according to any one of claims 14-17, wherein the primary air adjusting means actuates a device for adjusting the flow-rate of fuel injected into the auxiliary combustion chamber so as to maintain a substantially stoechiorhetrlc ratio between the flow-rates of primary air and fuel.

19. A pov/er unit according to claim 18, wherein ' the primary air adjusting means and" the fuel flow adjusting device are located in a movable member of the throttle means.

20. A po er unit according to claim.15 or 16, wherein said movable throttle member is formed with a tubular extension and the,.primary air adjusting means comprises at least one port formed in said tubular extension and adapted to be covered by a slide valve having an actuation surface subjected to the pressure existing in the downstream or u stream art of the b - ass i e and 41922/3: another actuation surface subjected to a counter pressure and to the action o a spring, said slide valve being connected to the adjusting means.

21. A power unit according to claim 20, wherein said counter pressure is pneumatic.

22. A power unit according to claim 21, wherein Λ said counter pressure is equal to or greater than atmospheric pressure.

23. A power unit according to claim 21, wherein said counter pressure is the pressure' in a regulation chamber connected to the admission of the engine through a needle adjustment device and provided with a calibrated air leak.

24. A power unit according to claim S or 19, in which the auxiliary combustion chamber is supplied by an injector of the return type, as herein defined, the means for adjusting the flow rate of fuel comprises a movable member determining the effective cross- sectional area of a variable nozzle as a function of the position of said movable member, said nozzle being arranged on a return path from the injector.

25. A power unit according to claim 18 or 19, in which the auxiliary combustion chamber is supplied by an injector of the non return type, as herein defined, . ' 41922/3 / wherein the means for adjusting the flow rate of fuel comprises a movable member determining the effective cross-sectional area of a variable nozzle as a function of1. he position of said movable member, said' nozzle being arranged on a passage through which high pressure ' fuel flows to the injector.

26. Λ power unit according to claim 24 or 25, wherein the variable nozzle comprises a needle with a conical portion adapted to project into an orifice by a variable extent.

27. A power unit according to claim 25 or 26, comprising a sliding valve regulator comprising a chamber placed in communication with the pressure of fuel upstream of the fuel flow adjusting device,, and a chamber placed in communication with the pressure of fuel donwstrea of the regulating device, this slide valve regulator covering or uncovering a port placing the first of the tv/o said chambers in communication with a delivery pipe.

28. A power unit .according to claim 27, wherein the slide valve regulator comprises a piston separating the two said chambers and subjected to the action of a spring acting in a direction opposite to the difference of pressure existing in the two said chambers.

29.. A power unit constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings .' , For the Applicants '^1 DR. REINH0¾D C<¾ AND PARTNERS By: