US2544111A - Carburetor - Google Patents

Description

2 Sheets-Sheet l Aww/b.

CARBURETOR H. SCHNEEBELI March 6, 1951 Filed Oct.y l

March 6, 1951 H. scHNEEBELl CARBURETOR f 2 sheets-sheet 2 Filed Oct. l, 1946 Patented Mar. 6, 1951 UNITED STATES OFI-"ICEv CARBURETOR Hugo Schneebel, Courbevoie,-France Application October 1, 194.6,..Se1fialN0- '100,395` In France October 19, 1945 (Cl. 2Gb-.44)

The present invention relates to -carburetors for internal combustion'engines, and more especially to carbureters of the kindfincludingon the one hand injecting means forsupplying gaseous or liquid fuel emulsied in primary airand on the other hand secondary air inlet means controlled by throttling meansfautomatically operated in response to variations of v-thesuction of the induction pipe leading to the engine.v

The essential object f-my invention isito -provide a carburetor of this type. which is better adapted to meet the requirements of 'practice than those used up to the .present time.-

Other objects of my invention will appear -from the following detailed description of some speciiic. embodiments of the invention.

Preferred embodiments of my invention Vwill be hereinafter described with referenceto the 1aecompanying drawings, given'merely bywayfvof example, and in which:

Fig. 1 is an axial sectional viewfof aiirstemloodiment of a carburetor-made accordingfto the present invention;

Fig. 2'is a detail view `on -a larger scale corresponding to Fig. 1;

Fig. 3 is an axial sectional view of asecond embodiment of my invention;

Fig. 4 is a cross sectionlfon the :line IV-IVfof Fig. 3;

Fig. 5 is a partial sectional viewofa modification of the embodiment of Fig. 3;

Fig. 6 is an axial sectionalview of athi-rd -embodiment of my invention.

In the embodiment of Fig.- l, the apparatus-is mounted on a base piece `I which forms-a pipe -2 one end of which is connectedwith'the engine intake. To the other endof/piecel is flttedlthe lower edge of a casing-3provided with-secondary air inlet ports 3a. This casing forms a seat for the secondary air throttlefvalve 4.. Caslng further forms a cylinder'ior apiston -5 integral withY throttle valve 4. Piece45is guided byv an axial rod 6 carried by a cover-1 vwhich closes casing-3 at the top thereof. The freeend of rod 6 forms a cylindrical headf8-L slidablel in` an--axial bore provided in valve 4." A spring Sis-interposed 'between this rhead Il and a shoulder I0 'of piece-4--5; said spring being wound around-redt.- Passages II provided in rod 6 and its head 8 connect the housing of spring-9 withf thefenglne induction pipe. This housingfcommunicates, on the otherhand, with the space between piston 5land cover- 1 due to a clearance `-I2vb'etween -rod 6 andjpiece' 4 5. Another spring I3 wound around rod 6,4` is interposed between cover 1 fand pieee4'5fand acts in opposition to spring 9,

Rod 6 is screwed. in cover 'I and extends there? through- It' carries, on the outside of said cover, a cap-shaped nut 'I4 which is also screwed on a central. :projection orboss-of cover 1. This .arrangement 'isz' intended to permit adjusting the strength' of spring -.9 by vlongitudinally displacing rod 6 and settingsaid rod in thedesired position.

Cover. 1 .extends above lateral projections of casing3: One of these projections -is provided with -ay-longitudinal conduit AI 5 in-communication. at,-. the bottom end thereof,l withv afradial conduit I6 of base piece I. Conduitliopens into an annularchamber I1 which surrounds theseat of valve V4.v At a: short-` distance below this seat, casing 3 is provided with a plurality of small holes I1afwhich connect chamber I1 with induction pipe'coupling 2. On-athe other band. at the top end thereof,I conduit I5 communicates, through aeradial. conduit-I8 provided in cover 1, with the space between said coverand piston 5. A needle Valve'-I9a.mcunted inthis cover permits varying thefsectionof the-bypass communication thus ierinfxeri;Y

The other lateral projection of body or casing 3 is provided -with a-longitudinal bore in which is slidably mounted the stem I 9-of a valve 20."l This valvefcooperates with a box which communicates, through a conduit 2| provided in cover1, with the space betweensaid cover and piston 5. Valve 20 is subjected to the action of a spring 22. Its stroke canine-adjusted by screwing or unscrewing the \seat-23fthereof.-= The otheriend of rod or stem- II 9.projects ..to. the outside. It is impermenent contact with aninclined surface-or cam `24 carriedy by one'ofthe operating levers 250i the injector means.

Said injector` means include a body- 26 fixed to base-piece] and `provided withv a lateral conduit 21 adapted to rit inline .with a ,radial conduit of saidpiece I OpeningintQannular chamber i1. An air inlet tubular piece 28 diametrallyopposed to conduit 21, serves for the inflowof fuel emulsifying air. Fuelis fed through an axial jet 29 controlled by a needle valve 30. This needle valve 4is sli'dablefin va sleeve 3| in body 26. On this sleeve 3| is coaxially mounted another sleeve 32, integral with .lever 25. .and provided `with external screw thrads A.. cap-shaped nut `33de engaged on .this threaded part., a second Operating levern34 being made integral with said nut. The stem of needle valve 30 extendsfreely throughv the top of cap 33. It is provided, on the outside of this cap, with a nut 35and a lock.

nut 35a and subjected to the action of a spring` 36' which applies saidjnutl against the top of cap V'33.

Lever 25 is connected with the throttle pedal whereas lever 34 is connected with a handle or lever located within reach of the drivers hand, for instance on the steering wheel.

The rst of these levers, to wit 25, serves to control the rate of feed of fuel to the carburetor according to the effort required from the engine. The other lever, to wit 34, is an independent controlling means. It allows opening or closing the fuel feed without modifying the adjustment obtained through lever 25.

When this last mentioned lever is in the position corresponding to idling of the engine, the stem I9 of valve 20 has its lower end located in a recess o. (Fig. 2) of clam 24, so that valve 2E) is wide open. It therefore permits air to enter from the outside into the space between cover 1 and piston 5 at a suiiicientxrate for preventing the formation of a vacuum in this space under the effect of the suction from the engine. 'Throttle valve 4 therefore remains on its seat and does not admit secondary air to the engine cylinders.

If, now, lever is operated in the suitable direction, needle valve is lifted from its seat through the intermediary of cap 33 and a greater amount of fuel is supplied through the fuel jet. At the same time, a sharp slope of cam 24 lifts the stem I9 of valve 20, which thus throttles the air inlet into the space between cover 1 and piston 5. The suction exerted by the engine can then act upon the top face of piston 5, which is moved upwardly, lifts throttle valve 4 from its seat and thus causes air to enter through ports 3a into pipe 2.

If lever 25 is further rotated in the same direction, the portion of ca'm 24 that is now acting upon the lower end of steml I9 is but little inclined. Valve 20 is therefore further closed but at a relatively slow rate. The suction in the space between cover 1 and piston 5 grows nearer and nearer to that existing in the engine. In the position of the parts corresponding to normal running conditions, this suction balances the resultant of the suction effect exerted on throttle 4 on the side o f the engine and of the respective actions of springs 9 and I3 for a given lift of valve 4 from its seat. This lift is, on the other hand, interrelated with the degree of opening of the fuel jet. In the embodiment of Figs. 3 and 4, easing 4| is in communication through its open base portion with the engine. It is provided with wide lateral air inlet ports 4|a. It is fitted with a throttle 42 the upper part of which constitutes a piston 43 slidable with a certain play in a suitable housing 44. The lower end portion of this throttle is adapted to move without friction in the neck 45 of casing 4|. This member 42-43 is guided by a rod 46 rigid with a cover 41 which closes box 4| at the top thereof. A Spring 48 interposed between this cover and member 42--43 urges piston 43 toward its seat 49 constituted by a shoulder of the inner wall of casing 4|. Member 42-43 is guided on its rod 46 by elements 50 which are not fluid-tight.

Below the lowest position of the bottom end of the throttle, I provide three transverse conduits 5| (Fig. 4) extending through the wall of casing 4|. They converge into a single chamber opposite which is fixed the body 52 of the injector device. This body is provided with a passage 53 communicating with the outside through a calibrated orifice 54. A fuel jet 55, supplied with fuel through suitable fuel feed means, opens transversely into passage 53. The outlet of jet 55 into passage 53 is controlled by a needle valve 56. This needle valve is slidable in a sleeve 51 integral with body 52. On this sleeve is coaxially mounted a disc 58, resting on a fiat portion of body 52 and held in fixed angular position on this body about the axis of sleeve 51. The upper face of disc 58 is provided with two inclined cam surfaces 59-59, symmetrically located with reference to the center of said disc. Sleeve 51 acts as a pivot for a coaxial sleeve 50, provided, at the base thereof with an annular flange 6|, integral with an operating lever 62. Flange '6| is provided, on its under face, with projections 63 arranged to cooperate with cam surfaces 59. The top end of sleeve 66 is closed by a screwed cap 64, provided with a hole affording a free passage for needle valve 55. A flange 55 carried by this needle valve bears upon the upper face of the end of said cap 64. A spring 66, xed to lever 52, carries a small block 66a engaged with a set of teeth provided along the upper edge of cap 64. This cap can thus be fixed in a given angular position about its axis while keeping the possibility of adjusting it so as to determine at will the degree of opening of needle valve 56 in the idling position. This same spring 66 is curved at the top so as'to bear against the flange 65 of needle valve 56 and to urge said needle valve toward its seat.

The upper face of the annular flange 6| of sleeve 60 is provided with another cam surface 61 intended to cooperate with push-piece 68 guided in a vertical housing of body 4|. Push piece 68 is intended to act upon a valve 69 subjected to the action of a spring 10 and located in a valve casing 1| screwed in the cover 41 of body 4|. The function of valve 69 is to control the feed of air from the outside into the space between piston 43 and cover 41, this air being supplied through orices 12 provided in the wall of casing 1| and a conduit 13 provided in cover 41. The initial degree of aperture of valve 69 can be adjusted by screwing or unscrewing valve casing 1| After adjustment, this valve casing 1| is fixed in position by means of a lock nut 1|a. Valve 69 is carried by a stem which projects outwardly from valve casing 1| and which is adapted to act as a push-piece on a rocker lever 14, pivoted at 15 on a support 16. This support is carried by the top end of guiding rod 46, against which it is fixed by means of two locking plates 11 secured through nuts 18.

At the end thereof opposed to push-piece 68, rocker lever 14 cooperates with a screw 19 the base of which is adapted to bear against the top face of a cap 80, screwed on the end of the stem of a valve 8|. This valve 8| is housed in a valve casing 82 fitted in casing 41. Valve 8| is provided with a return spring 83 for urging it toward its seat. It controls the communication between the space between piston 43 and cover 41 and the suction of the engine, this communication taking place through a radial conduit 84 provided in cover 41, vertical conduit 85 and transverse conduit 86, both provided in casing 4|, and the central bore of said casing, below throttle 42.

This carburetor device works in the following manner:

When the engine is idling, needle valve 56 permits a minimum amount of fuel to be fed through the injector device. On the other hand, secondary air flows in, at a very low rate, through the leak existing between the lower portion of the throttle and the inner wall of the neck 45 of the central bore of casing 4|.

Throttle 43 cannotlift, -since airr inlet valve- 69-'is wide `open, thuslpreventing the suction from the engine fromfexertin'ga lifting action on piston 43-through cond-uits85, .86vand 84; However, -in

case of necessity, screwlgfmight beadjusted insuch vmanner-as to have valve 8| moreor less open for these conditions of operation.A

When lever 62 Ais operated in such manner as to lift needle valve 56' away-from its seat, val-veV 69 tends simultaneously to be lifted through the in1` termediate ofl push-piece 68`` and accordingly .tol

under the action of rocker lever\14iand1.the vacuf um created Vbyhthesuction. from the engine is transmitted to the space at the rear of piston 43 through the direct way constituted by passages 84, 85 and- 86;so that thelft of throttle 42v is accentuated by-the action of the above mentioned valves:Vl

In the modica-tionillustrated by Fig-5, there is no connection between-valve 65 and valveI 6I. This last mentioned valve is intended in this case to work automatically. In place of opening towards the suction of the motor as -in the preceeding modification it -opens in the opposite direction, As shown it comprises a center punch 8|, guided longitudinally in a perforation of the valve box 82 and provided exteriorly of the valve box with a head 90. A spring 83 which is interposed between the head 90 and the valve box 82 tends to raise the center punch When the motor is stopped the valve 8l is thus raised to a maximum. When the motor idles the valve 8l is on the contrary applied against its vseat by the effect of atmospheric pressure, the depression then created by the motor in its suction conduit being at a maximum. For the other speeds of the motor the raising of the valve 8| is more or less large according to the value of the depression in the suction conduit of the motor and this depression becomes more or less sensitive consequently in the space located in back of the piston 45 through the conduits 84-85.

In the embodiment illustrated by Fig. 6, I make use, for controlling the secondary air intake, of a throttle 42 similar to that of Fig. 3, this throttle being integral with a piston 43'and being mounted slidable on a central guiding rod 46 inside body 4I. Rod 46 projects beyond the upper face of cover 41. Its upper end is provided with a tightening nut 46a, screwed thereon, which applies in an annular recess of a central tubular inward projection of cover 41 a split ring 46h, partly housed in a circular groove of rod 46.

A spring 48 urges throttle 42 toward its seat, against which it is applied through its piston portion 43. The lower end of throttle 42 is dimen sioned to pass freely through the neck formed by the central passage of body 4i. Ports such as 41a are provided in the wall of body 4! for the inflow of secondary air. Fuel emulsied with primary air is fed through a conduit 53 provided in the body 52 of the fuel injection device.

Needle valve 56, which controls the section of flow through fuel jet 55, is subjected to the action of a return spring 66 one end of which bears against a projection 41a of cover 41, said spring end being engaged about a screw 41h.

Needle valve 56 is operated by means of a lever 62. This lever .is `integral .with a .disc 6I, itself integralfwith a sleeve 66 pivotally mounted.

on .a sleeve 51 integral with body 52. Sleeve` 60 is c-overed with a screwed cap 54 against which bears thehead of the needle valve. Cap 64.is

provided on its upper edge with teeth with which can cooperate a small locking block Vcarried by spring 66a. A spring 66h the upper end of which bears against the projection 41a of vcover 41, urges cap 64 inthe downward direction.

Disc 6l is provided, on its under face, with projections 63'4 adapted to cooperate with cam portions 59 symmetrically disposedwith respect to the center of another disc 56 secured .to body 52: On itsupper face, Idisc 6| is provided with another cam portion 61 which isvadapted to cooperate With theend of. a push piece 68.v The other end oftthis push piecev is .in contact with a valve filsubjected to the action of a return spring 16.

A conduit opens under this valve 69. This conduit 85,- provided in the wall of body'lii opens, at its other end, into the central wall ofsaid body 4 I., below throttle 42.

Valve 69 is vhoused in a valve casing 1l screwed in cover 41, in adjustable position. On the side of valve 69 opposed to the opening of conduit 85, this valve casing communicates, through a conduit 84, with the space provided in body 4I above the piston 43 of throttle valve 42.

A passage 81 provided in the wall of this valve casing 1l permits the now of air from the outside into this space above piston 43. Passage 81 may be controlled by means of a ring nut 88 screwed on valve casing 1| so as to permit of adjusting at will the section of now through said passage. A spring 89 fixed to cover 41 is adapted to engage the toothed edges of parts 1I and 88 so as to permit bringing and holding them in the desired relative position.

Thus the section of flow through passage 81 remains constant once it has been adjusted by means of nut 88.

On the contrary, the communication of the space on the rear of piston 43 with the suction conduit of the engine through passages 84, 85 depends upon the degree of opening of valve 69,

which degree of opening is itself determined inaccordance with the position of the needle valve 56 which controls the fuel flow rate. The cam portions of disc 6| are so determined that valve 69 opens more and more as the section of flow through fuel jet 55 is being opened more and more by throttle valve 56.

Thus, as in the preceding embodiments, the inflow rate of the secondary air stream is automatically increased in response to increases of the fuel flow rate by upward displacements of throttle 42 produced by the suction of the engine acting more and more on the rear face of piston 43 integral with said throttle 42.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and eicient embodiments of the present invention, it should be' well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended Within the scope of the accompanying claims.

What I claim is:

1. A carburetor for an internal combustion engine which comprises, in combination, an induction pipe to be connected With said engine,

throttle valve means for controlling the flow of secondary air from the atmosphere to said pipe, pneumatic means for controlling said throttle valve means, said pneumatic means including a variable Volume chamber, a passage between said chamber and the atmosphere, a passage between said chamber and the portion of said induction pipe on the downstream side of said throttle valve means, means for controlling the feed of fuel to the portion of said induction pipe on the downstream side of said throttle valve means, means operatively connected with said fuel feed control means for controlling the flow section through the second oi said passages, and manual control means for adjusting the flow section through the iirst of said passages.

2. A carburetor for an internal combustion engine which comprises, in combination, an induction pipe adapted to be connected with said engine, a hollow casing opening at one end into said pipe, a throttle valve in said end of said casing for controlling the communication between said casing and said pipe, the other end of said casing being closed and forming a cylinder, a piston rigid with said throttle Valve adapted to cooperate with said cylinder, the Wall of said casing between said throttle valve and said piston being provided with at least one secondary air intake port, a passage between the closed end of said cylinder and the atmosphere, a passage between the closed end of said cylinder and said induction REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,237,395 Shakespeare et al. Aug. 21, 1917 1,258,389 Bergen Mar. 5, 1918 1,823,346 Burdick Sept. 15, 1931 2,091,273 Crippen Aug. 31, 1937 2,091,751 Crippen Aug. 31, 1937

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