US2751897A

US2751897A - Combustible fluid supply apparatus for internal combustion engines

Info

Publication number: US2751897A
Application number: US461574A
Authority: US
Inventors: Schweizer Alfred; Brecher Karl
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1954-10-11
Filing date: 1954-10-11
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

June 26. 1956 A. SCHWEIZER ETAL 2,751,897 COMBUSTIBLE FLUID SUPPLY APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed 001;. 11, 1954 IIIII JN VENTOR 5 HLFRED Sch/M925) A110 KARI. 8REc/7ER United States Patent 6 COMBUSTIBLE FLUID SUPPLY APPARATUS FOR INTERNAL COMBUSTION ENGINES Alfred Schweizer, Stuttgart-Degerloch, and Karl Brecher, Stuttgart-Oberturkheim, Germany, assignors to Robert Bosch G. in. h. H., Stuttgart, Germany Application October 11, 1954, SerialNo. 461,574

12 Claims. (Cl. 123=-140) The present invention relates to internal combustion engines with spark ignition and more particularly to structure for supplying a fuel-air mixture for such engines.

It is known with certain internal combustion engines with spark ignition to automatically control the fuel supplied to the fuel-air mixture in accordance with the pressures upstream and downstream of a butterfly valve in the intake manifold. Because it is necessary to maintain this valve at least slightly open for idling purposes, it is difficult to automatically control the fuel supply in the best possible manner since the air pressure in the intake manifold at the upstream and downstream sides of the butterfly valve must be carefully regulated not only for the air supply when idling but also for the fuel supply. Furthermore, with such devices the fuelair mixture does not change to the desired degree as fast as is desired upon opening of the butterfly valve because of the relatively constricted path of fluid flow between the intake manifold and the automatic fuel sup: ply regulator.

It is an object of the present invention to overcome the above drawbacks by providing a means for supplying air for idling purposes when the valve in the intake manifold is completely closed so that in this Way it is possible to regulate the fuel supply for idling purposes with a completely closed valve in the intake manifold.

Also, it is an object of the present invention to provide a means for regulating the air supply for idling. Furthermore, it is an object of the present invention to provide a means which permits the flow of air to a fuel supply regulator to be greatly increased, as compared to known constructions, upon opening of the manifold valve so that the desired change in the fuelair ratio may be quickly regulated automatically to the desired extent.

An additional object of the present invention is to provide an apparatus which accomplishes the above objects and is fully automatic in its response to operation of the butterfly valve in the intake manifold.

With the above objects in view, the present invention mainly consists of an internal combustion engine with spark ignition which includes a support means and an enclosure carried by the support means and having a wall portion formed with an opening passing therethrough to provide communication between the interior of the enclosure and the outer atmosphere. A diaphragm is fixed to and extends across the interior of the enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through the said opening in the enclosure wall portion. An elongated fuel supply adjusting member is carried by the support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, and this adjusting member extends into the chamber communicating with the outer atmosphere and has an end connected to the diaphragm so that movement of the latter upon a change in the ratio between pressures in the chambers moves the adjusting member for automatically adjusting ice the fuel supply. An intake manifold supplies air to be mixed with the fuel, and this intake manifold has a wall portion formed with a pair of bores which communicate with each other. A conduit means leads from the chamber which does not, communicate with the outer atmosphere to one of the bores to provide communication with the latter chamber and that portion of the intake manifold where the said one bore is located. A valve member is turnably carried by the intake manifold by the interior thereof, and this valve member in its closed position engages the inner surface of the intake manifold and has an edge portion located between the bores. A passage means communicates with the interior of the intake manifold and bypasses the valve member therein when the latter is in its closed position to supply air to the fuel mixture for idling purposes.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description from a specific embodiment when read in connection with the accompanying drawing, wherein the structure is illustrated partly in section and partly diagrammatically.

Referring now to the drawing, it will be seen that a housing 1 of a fuel injection pump turnably supports therein a cam shaft 2 having a cam which reciprocates a piston 3 which supplies at each pressure stroke a predetermined amount of fuel. The piston 3 is provided with a substantially helical slot communicating with its head end, as is shown in the drawing, and in a manner well known in the art the amount of fuel supplied at each pressure stroke of the piston may be regulated by turning the piston 3 about its axis. For this purpose, the piston 3 is provided below the cylinder in which it slides with a gear fixed to the piston and meshing with a rack which forms an elongated fuel-supply adjusting member and which is slidably carried for reciprocation by a wall of the housing 1 which forms a support means for the member 4.

The housing 1 carries at its right wall, as viewed in the drawing, an enclosure having a diaphragm 5 fixed to and extending across the interior thereof to divide the enclosure into a pair of chambers 6 and 8 respectively located at the right and left of the diaphragm 5, as viewed in the drawing. The wall portion of the enclosure is formed at chamber 8 with an opening 7 providing communication between the interior of chamber 8 and the outer atmosphere. The right end of rack 4 is fixed to the diaphragm 5, this rack 4 extending across the interior of chamber 8, so that upon a change in the ratio between the pressures in chambers 6 and 3 the diaphragm will move to shift rack 4 in one direction or the other to regulate automatically the amount of fuel supplied to the fuel-air mixture. A spring 42 is located in the chamber 6 and engages the diaphragm 5 and the right wall of chamber 6, as viewed in the draw ing, to urge the diaphragm 5 to the left, as viewed in the drawing.

The chamber 6 communicates through a conduit 9 with the interior of an annular member 10 fixed to the exterior of the intake manifold 12 by a screw member 11, the manifold 12 having a thickened wall portion at the place where

elements

10 and 11 are located. The screw member 11 is formed with an axial bore 15 which communicates through aligned openings in

members

11 and 10 with conduit 9, and, as shown in the drawing, this screw member 11 is threadedly connected to and extends through a bore passing through the wall of manifold 12 from the interior to the exterior thereof. Thus, air flow ing along the interior of manifold if; in the direction of arrows 13 may flow along the bore 15 of screw member 11 to the interior of conduit 9 and along the latter to the chamber 6. The bore 15 of screw member 11, which communicates with the conduit is provided with a portion of reduced cross section terminating in an inlet end 17 located at the interior of the manifold 12. As is evident from the drawing, this inlet opening 17 is located downstream of a butterfly valve 2% turnahly located within the manifold 12 and shown in the drawing in its closed position where the entire outer periphery of valve 29 engages the inner surface of the manifold.

The bore of manifold 12 in which screw member 11 is located is somewhat larger than the latter to provide an annular chamber 23 located about the screw member 11. The latter is formed with a bore 22 providing communication between chamber 23 and bore 15. A bore 24 is formed in the wall of manifoldlZ and extends in an upstream direction from the chamber 23. A needle valve member 25 is threadedly carried by the manifold 12 and extends into the interior of bore 24-to regulate the flow of air therethr'ough. A second bore 26, which is upstream .of the bore in which screw member 11 is located, extends from the bore 24 to the interior of the manifold 12, this bore 26 having an inlet opening 27 located closely adjacent to that part of valve 2b which moves against the direction of air flow upon opening of the valve. The bore 24 continues in the upstream direction beyond bore 26 to a bore 36 which also communicates with the interior of the manifold 12, and the manifold is provided with a nozzle 31 located in the bore and having an inlet opening 32 located upstream of opening 27. This bore 30 is closed at its outer end by a plug 33 threaded into the wall of the manifold 12. Thus, by removing plug 33 it is an easy matter to exchange one nozzle 31 for another one.

A passage 34 is formed entirely within thewall of the manifold 12 and leads from the bore 30 along an entirely independent path to the chamber 23. A closure or constricting member 35 extends across the passage 54 to close the latter or to constrict the latter to a predetermined extent, this member 35 being movably mounted on an exterior wall portion of manifold 12 for movement a into and out of the passage 34. The member 35 is shown in the drawing in the position where it closes the passage 34, and the valve 29 is also closed in the position of the parts shown in the drawing. In order to close valve 35 when valve 29 is closed and to open valve 35 when valve 20 is opened, a shaft 35 is turnably carried by the manifold 12, has the valve 2% fixed thereon so that turning of shaft 36 turns valve 29, and the shaft 36 extends to the exterior of the manifold and has a lever 37 fixed thereto and engaging member 35 to maintain the latter closed against the action of a spring 38 located about ember 35 at the exterior of the manifold and engaging a head end of member 35 and the manifold to urge member 35 to its open position.

The shaft 36 carries at the side of manifold 12 opposite from lever 37 and operating lever 39 which is turned by the operator in a known way for opening and closing the valve 20.

The wall of manifold 12 is further formed with a bypass passage means 40 which may be constricted to predetermined extent by a needle valve member 41 threadedly carried by the manifoldlZ and extending into the interior of passage '46, as shown in the drawing. This passage 40 bypasses the closed valve 20 and serves to supply air for idling purposes to the fuel air mixture of the engine, so that in this way it is possible for the valve 20 to remain tightly closed when the engine is idling. In this manner, it is much easier to adjust with needle valve 25 the pressure in chamber 6 which controls the amount of fuel supplied to the combustible mixture and which pressure is determined by the combination of the pressures at the openings 17, 27, and 32, than is the 4 case when idling air is suppliedto the engine by maintaining the valve 20 in a slightly open position.

After the valve 20 is slightly open, the spring 33 opens the valve 35 so that opening 32 communicates through passage 34 with chamber 23 and in this way the opening 32 need not communicate at this time with the chamber 6 through the bore 24 which is constricted by the needle valve 25. This effect is heightened by the fact that the cross section of passage 34 is greater than that of bore 24. This arrangement provides upon opening of the valve 20 a smaller difference in pressure between the chambers 8 and 6 so that the spring 42, which acts against this difference in pressure, is capable of moving the membrane 5 and the rack 4 in a position providing a larger supply of fuel than would, otherwise be the case. The more the valve 2% is open the smaller becomes the difference in pressure between chambers 8 and 6 and the greater is the amount of fuel supplied by the action of spring 42. In this way it is possible with the disclosed structure of the invention to provide the engine with the best possible fuel-air mixture under all operating c ditions.

While the invention has been illustrated and described as embodied in combustible mixture regulating device for internal combustion engines with spark ignition, it is not intended to be limited to the details shown, since various modifications and structural changes be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for vari ous applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invert-- tion and, therefore, such adaptations shot and are intended to be comprehended within the r ning and range of equivalence of the following claims.

What is claimed as new and desired to bc secured by Letters Patent is:

1. In an internal combustion engine with sparlc ignition, in combination, support means, an enclosure carried by said support means and having a wall portion formed with an opening passing therethrough to provide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuel-supply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuelair mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for automatically ad justing the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formed with a pair of bores which communicate with each other; conduit means leading from the other of said chambers to one of said bores to provide communication between the interior of said other chamber and that portion of the intake manifold where said one bore is located; a valve member turnably carried by said intake manifoldin'the interior thereof, said valve member in its closed position engaging theinner surface ofsaid manifold and having an edge portion located between said bores; passage means communicating with the interior of said intake manifold and bypassing salt valve member in the closed position thereof for supplying air to the fuel mixture for idling-purposes; and means located on and communicating with the interior of said passage means for adjustably constricting the cross-sectional area of a'portion thereof to adjust the flow of air through said passage means.

2. In an internal combustionengine with spark ignition, in combination, support means; an enclosure carried by said support means and having a wall portion formed with an opening passing therethrough to provide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuelsupply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for automatically adjusting the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formed with three bores communicating with the interior of said intake manifold and with each other and arranged along the length of said intake manifold so that the intermediate one of said bores is located between an upstream bore and a downstream bore; conduit means leading from the other of said chambers to said downstream bore to provide communication between the interior of said other chamber and the portion of the intake manifold where said downstream bore is located; a valve member turnably carried by said intake manifold in the interior thereof, said valve member in its closed position engaging the inner surface of said manifold and having an edge portion located between said downstream and intermediate bores and closely adjacent to the latter; first passage means communicating with the interior of said intake manifold and bypassing said valve member in the closed position thereof for supplying air to the fuel mixture for idling purposes; second passage means providing communicating between said upstream bore and downstream bore through a path different from that providing communication between said three bores so that said upstream bore may communicate with said other chamber through said downstream bore independently of said intermediate bore; constricting means carried by said second passage means for constricting the flow of fluid therethrough; and operating means connected to said valve member for movement therewith and engaging said constricting means for operating the latter upon movement of said valve member.

3. In an internal combustion engine with spark ignition, in combination, support means; an enclosure carried by said support means and having a wall portion formed with an opening passing therethrough to provide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuelsupply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for automatically adjusting the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formed with three bores communicating with the interior of said intake manifold and with each other and arranged along the length of said intake manifold so that the intermediate one of said bores is located between an upstream bore and a downstream bore; conduit means leading from the other of said chambers to said downstream bore to provide communicating between the interior of said other chamber and the portion of the intake manifold where said downstream bore is located; a valve member turnably carried by said intake manifold in the interior thereof, said valve member inits closed position engaging the inner surface of said manifold and having an edge portion located between said downstream and intermediate bores and closely adjacent to the latter; first passage means communicating with the interior of said intake manifold and bypassing said valve member in the closed position thereof for supplying air to the fuel mixture for idling purposes; second passage means providing communication between saidupstream bore and downstream bore through a path different from that providing communication between said three bores so that said upstream bore may communicate with said other chamber through said downstream bore independently of said intermediate bore; constricting means carried by said second passage means for constricting the flow of fluid therethrough; and operating means connected to said valve member for movement therewith and engaging said constricting means for operating the latter upon movement ofv said valve member, and said operating means positioning and constricting means in a position completely closing said second passage means when said valve member is in its closed position in said intake manifold.

4. In an internal combustion engine with spark ignition, in combination, support means; an enclosure carried by said support means and having a Wall portion formed with an opening passing therethrough to provide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuel-supply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for automatically adjusting the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formed with a pair of bores which communicate with each other; conduit means leading from the other of said chambers to one of said bores to provide communication between the interior of said other chamber and that portion of the intake manifold where said one bore is located; a valve member turnably carried by said intake manifold in the interior thereof, said valve member in its closed position engaging the inner surface of said manifold and having an edge portion located between said bores; passage means communicating with the interior of said intake manifold and bypassing said valve member in the closed position thereof for supplying air to the fuel mixture for idling purposes, said passage means being in the form of an elongated opening formed in the wall of said intake manifold; and needle valve means carried by said intake manifold and extending into the interior of said passage means for adjusting the flow of fluid therethrough.

5. in an internal combustion engine with spark ignition, in combination, support means; an enclosure carried by said support means and having a wall portion formed with an opening passing therethrough to pro vide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuel-supply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for auto* matically adjusting the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formedwith a pair of bores which communicate with each other; conduit means leading from'the' other of said chambers to one of said bores to provide communication between the interior of said other chamber and that portion of the intake manifold where said one bore is located; a valve member turnably carried by said intake manifold in the interior thereof, said valve member in its closed position engaging the inner surface of said manifold and having an edge portion located between said bores; passage means communicating with the interior of said intake manifold and bypassing said valve member in the closed position thereof for supplying air to the fuel mixture for idling purposes, said passage means being in the form of an elongated opening formed in the wall of said intake manifold; needle valve means carried by said intake manifold and extend ing into the interior of said passage means for adjusting the flow of fluid therethrough; and second needle valve means carried by said intake manifold in the path of communication between said bores for regulating the flow of fluid therebetween.

6. In an internal combustion engine with spark ignition, in combination, an intake manifold formed in a wall portion thereof with a pair of bores extending from the interior of said intake manifold and spaced along the length thereof so that one of said bores is upstream of the other of said bores, and said intake manifold being formed in its wall portion with a third bore providing communication between said pair of bores, said intake manifold also being formed at another wall portion thereof with an elongated passage of a larger cross section than said bores and having inlet and outlet ends communicating with the interior of said manifold, said inlet end of said passage being located upstream of the outlet thereof and said passage ends being being spaced from each other by a distance greater than that of said pair of bores; 21 butterfly valve pivotally carried by said intake manifold in the interior thereof and being turnable to and from a closed position where said valve has its entire periphery in engagement with the inner surface of said intake manifold, said periphery of sad valve in its closed position being located substantially midway between said ends of said passage and between said bores nearer to said upstream bore than said downstream bore; a first needle valve member turnably carried by said intake manifold and extending into the interior of said third bore to regulate the flow of fluid between said bores; a second needle valve member turnably carried by said intake manifold and extending into the interior of said passage for controlling the flow of air therethrough; and a conduit communicating with said downstream bore and leading therefrom to a means for automatically controlling the supply of fuel to the engine in accordance with the ratio between the pressure in said intake manifold at said pair of bores and atmospheric pressure,

7 In an internal combustion engine with spark ignition as defined in claim 6, said intake manifold being formed with a fourth bore located upstream of said pair of bores, said fourth bore communicating with said third bore and through the latter with said pair of bores; fluid guiding means carried by said manifold and leading from said fourth bore to said first bore through a path different from said third bore; a closure member carried by said fluid guiding means for movement across the same 'to restrict said fluid guiding means; spring means engaging said closure member to urge the same outwardly of said fluid guiding means; and an arm fixed to said butterfly valve for turning movement therewith, engaging said closure member, and maintaining the latter in a position closing said fluid guiding means when said butterfly valve is closed so that said closure member opens said fluid guiding means when said butterfly valve is opened. 7

8. In an internal combustion engine with spark ignition as defined in claim 7, said fluid guiding means being in the form of a passage having a larger cross section than said bores.

9. Man internal combustion engine with spark ignition, in combination, support means; an enclosure carried by said support means and having a wall portion formed with an opening passing therethrough to provide communication between the interior of said enclosure and the outer atmosphere; a diaphragm fixed to and extending across the interior of said enclosure to divide the latter into a pair of chambers one of which communicates with the outer atmosphere through said opening; an elongated fuel-supply adjusting member movably carried by said support means for adjusting the supply of fuel to a fuel-air mixture used in the engine, said adjusting member extending into said one chamber and having an end connected to said diaphragm so that movement of the latter upon a change in the ratio between pressures in said chambers moves said adjusting member for automatically adjusting the fuel supply; an intake manifold for supplying air to be mixed with the fuel, said intake manifold having a wall portion formed with three bores communicating with the interior of said intake manifold and with each other and arranged along the length of said intake manifold so that the intermediate one of said bores is located between an upstream bore and a downstream bore; conduit means leading from the other of said chambers to said downstream bore to provide communication between the interior of said other chamber and the portion of the intake manifold where said downstream bore is located; a valve member turnably carried by said intake manifold in the interior thereof, said valve member in its closed position engaging the inner surface of said manifold, and having an edge portion located between said downstream and intermediate bores and closely adjacent to the latter; passage means providing communication between said upstream bore and downstream bore through a path dif-' ferent from that providing communication between said three bores so that said' upstream bore may communicate with said other chamber through. said downstream bore independently of said intermediate bore; constricting means carried by said passage means for constricting the flow of fluid therethrough.

10. In an internal combustion engine as recited in claim 1, the pair of bores of said intake manifold communicating with each other through a first path; second passage means providing communication between said bores through a second path different from said first path; and constricting means carried by said second passage means for constricting the flow of fluid therethrough.

11. In an internal combustion engine as recited in claim 10 and wherein an operating means is connected to said valve member for movement therewith and engages said constricting means for operating the latter upon movement of said valve member.

12. In an internal combustion engine as recited in claim 11, said operating means positioning said constricting means in a position completely closing said second passage means when said valve member is in its closed position in said intake manifold.

References Cited in the file of this patent UNITED STATES PATENTS 2,623,510 Schweizer Dec. 30,. 1952 2,633,115 Waring Mar. 31, 1953 2,659,354 Nicolls Nov. 17, 1953 FOREIGN PATENTS 653,586 Great Britain May 16, 1951