US3284066A

US3284066A - Carburetors

Info

Publication number: US3284066A
Application number: US279443A
Authority: US
Inventors: Biver Jean
Original assignee: Societe du Carburateur Zenith SA
Current assignee: Societe du Carburateur Zenith SA
Priority date: 1962-05-17
Filing date: 1963-05-10
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08
Also published as: GB1045701A; FR1339530A

Description

Nov. 8, 1966 Filed May 1o, 1963 J. BIVER CARBURETORS Fig.:

5 Sheets-Sheet l Nov. 8, 1966 J. BNER 3,284,066

CARBURETORS y Filed May 10, 1965 5 Sheets-Sheet 2 United States Patent O 3,284,066 CARBURETORS Jean Biver, Paris, France, assignor to Societe du Carburateur Zenith, Lyon, France, a company of France Filed May 10, 1963, Ser. No. 279,443 Claims priority, application France, May 17, 1962, 897,902 2 Claims. (Cl. 261-70) A certain number of essentials are required of modern carburetors and, from these, certain conditions result which are fairly readily reconciliable.

Thus, the need to avoid the phenomena due to boiling of the petrol (percolation) leads to the necessity of protecting the carburetion circuits as much las possible from the ow of heat coming from the engine.

The ever decreasing space available under the bonnets which cover the engines of modern motor cars results in carburetors being made off as llow height and as compact as possible.

The desire for constancy of characteristics as between carburetors of the same manufacturing type or series necessitates very great m-achining precision.

Finally, for the sake of reduction of cost, the greatest possible simplicity of manufacture and assembly is necessary.

It is an object of the invention to provide a carburetor which will meet these various requirements in a satisfactory manner.

According to the invention there is provided a carburetor comprisinga main body containing a constant-'level fuel chamber of the customary form, -a cover for closing said main body, and a block, hereinafter called the carburetion block, which is separate from the main body `and which provides the whole, or at least almost the whole, of a system of ducts and orifices through which fuel passes for the carburetion of air drawn lin by the engine. The canburetion block bears on the main body along a horizontal plane and is adapted either to t the main body or to rest on the perimeter of this body. Although substantialy the whole of the carburetion system is formed in t-he block, there is -an exception in the case of the slow-running duct, which extends as far las the throttle valve.

With such 'an arrangement the carburetion block can be machined separately and the arrangement aftords many advanatges for the yachievement of the various conditions lset forth above.

Preferably, the canburetion block adjoins a section of the main emulsion and yair-mixing passages, and thus facilitates the provision of an insulating gasket between the block land a neck portion by means yof which the carburetor is connected to an engine. Such a -gasket outs 'oi the flow of lheat from the engine through the wall of the neck portion.

Further features of the invention will appear from the description which follows, which is given with reference to the accompanying drawings land by way of example only, it being understood that both the features described a-nd those appearing from the drawing come within the scope of the invention.

In the drawings:

FIGURES 1 to 6 show one constructionai form'of the invention, 4as applied to -a single-body carburetor. In these figures:

FIGURE 1 is a longitudinal section showing in external view, the carburetion block which constitutes a part off this form of carburetor.

FIGURE 2 is a plan view of the block of FIGURE 1;

FIGURE 3 is a view of the block from below;

FIGURE 4 is a plan view of a main body which constitutes part of the carburetor;

3,284,066 Patented Nov. 8, 1966 ice FIGURE 5 is a vertical section of the carburetor as a whole and FIGURE 6 is a partial section at right angle to the plane of FIGURE 5; it shows -diagrammatically parts of the slow-running circuit Which have been off-set angularly for illustration.

The carburetor shown in FIGS. 1 to 6 isof the downdraft type. It comprises a main body 1 which terminates at the top in the horizontal plane A-A (FIGURE 1) ywith la horizontal rim 1b and which contains the vusual constant-level chamber 2 for the fuel. The main body is surmounted by the cover or top 4 which is connected to the main body in the horizontal plane A--A and which carries the air intake S equipped with an a-ir choke or strangler 6. The lower horizontal surrface of the cover is designated 4b. The main body bas at the lower part thereof, a neck section 7 intended to be connected to the induction manifold ofthe engine ian-d containing `a throttle valve 8i. The controls for the air choke 6 and for the throttle valve I8 are not shown in detail since they may be constructed in any one of Ithe usual ways.

In the main body 1 is a so-called carburetion block 9 which forms one 'of the principal features of the present invent-ion. This block contains the whole of the ducts and orifices through which fuel coming from the constantlevel chamber 2 enters the system which serves to carburet air intering through the intake 5. The block 9 includes a tubular portion 9a which serves for the passage of air to be carbureted a-nd is disposed between the portion which provides the air intake 5 and the neck section 7. The portion 9a rests, by means of its annular surface 9b, on Ia bearing surface 1a of the main body-:and terminates at the top in the common plane A-A of main cup body 1 and the cover 4. A-n insulating gasket 10` is interposed between the bearing surface 1a of the main body and the annular surface 9b of the block.

The block 9 is separate from the rnain body 1 and the cover 4 yand can therefore be machined separately before being assembled with the cover 4 and the main body.

Fuel is conveyed through a pipe 11 to -an orice 12 provided in the seat of the needle valve 13 which regulates the admission of fuel into the constant-level chamber and which, for this purpose, is actuated in the usual manner by a float 14. 'I'Ihis oat comprises two elements 14 and 14a which are pivotally lmounted on the block 9 at 15 and 15a and therefore Iadjoin the block.

Bores are drilled in the block 9, which bores are oblique in the form of embodiment illustrated and in which a main jet 16 and a slow-running jet 18 are arranged inthe usual manner. The main jet 16 is followed by an atomizer 17 (FIGURE 5), which has lateral holes 17a through which enters air coming from a calibrated hole 23. Air entering through the holes 17a serves to form the main emulsion with fuel passing through the jet 16. This emulsion escapes through the outlet tube 19, the end of which is cut in the manner of a whistle and opens into the diffusion venturi member or cone 20 which is integral with the block 9 and is located coaxially with the tubular portion 9a. As will be seen in FIGURE 2, the venturi member 20 is carried by an arrn 21 of the block which has a calibrated orifice 22 formed therein for degassing ventilation, in addition to the orice 23 which, as previously mentioned, serves for the admission of air for forming the emulsion in the atomizer 17. The presence of the arm 21 means that the tubular portion 9a is not perfectly circular in form, as shown in FIGURES 2 and 3, but this is of no importance from the point of View of the operation of the carburetor.

The carburetor includes a slow-running devicewhich is shown diagrammatically in vertical section in FIGURE 6 and comprises a duct 24 in the block 9, extending from the slow-running jet 18, a duct 25 in the cover 4 and a duct'26"'in the main 'body-1, the duct '26 terminating, downstream of the throttle valve, in an outlet orifice 27 controlledl by an adjusting screw 28. The duct 26 may be provided with a progressionvor advance orifice 29 opening into the zone at which the throttle member 8 rests in the closed `position thereof. A calibrated hole 30 -is provided in the cover 4 and opens inside the air intake to afford communication between the outside air and the upper part of the slow-running duct 26, so as to avoid siphon effects.

In addition to the main carburetion ducts and the other elements which have been described, the block 9 may be provided also with other devices which are usually provided in carburetors, such as a power enriching device and an accelerating pump, the principle of the invention being to provide on the block, separate from the main body and the cover, the maximum number of elements and devices serving for carburetion. Thus, in FIGURE 2 there is shown at 22a the outlet pipe of an accelerating `pump which is mounted in the block 9 at 22h.

In the embodiment illustrated, the block 9 is fixed to the inside surface of the cover 4 before the latter is mounted on the main body 1. The fixing of the block 9 to the cover 4 is effected by using as a connecting screw, a threaded member 31 which contains the needle valve 13. This member 31 has six operating faces 31a which lare located below the block 9 and is screwed by means of its upper threaded end into the portion 11a of the cover 4 which provides a continuation of the petrol inlet duct 11. The assembly constituted by the cover 4 and the carburetion block 9 is assembled with the main body 1 by fitting the block 9 into the body 1 and the cover 4 is then fixed to the main body 1 by any suitable means, such as screws. K

It will be noted that the described arrangement of the block enables a gasket 10, which is a relatively thick insulating gasket, to be' interposed between the block 9 and the tubular neck portion 7 which is connected to the engine. Thetransmission of heat from the engine to the carburetion ducts by conduction through the metal walls is checked. It is thus possible to combat the phenomena of boiling of the fuel in the carburetion system and thus to avoid the drawbacks which follow therefrom. It will ybe noted that in the embodiment shown in FIGURES 1 to 6, the plane of the gasket disposed between the carburetion block 9 and the main body 1 is below the level of the fuel in the constant-level chamber 2, which level is itself below the plane of the joint A-A between the cover and the main body.

Many other constructional forms of the invention may be devised without departing from the scope thereof, as defined by the appended claims.

What'I claim is:

1. A carburetor having an induction passage comprising a main body, a constant level fuel chamber and a first section of said induction passage in said mainbody, a horizontal rim at the upper end of said main body above the fuel level in said fuel chamber, a horizontal bearing surface provided in said main body below the fuel level and surrounding the upper end of said first induction passage section, a carburetion block in said main body separate therefrom and providing a second section of said induction passage coextensive with said first section, fuel passages in said block for connecting said fuel chamber with said second induction passage section, Vahorizontal annular surface provided insaid block around the lower end of said second induction passage section, an insulating gasket interposed between said bearing surface of the main body and said annular surface of said block, said block having a horizontal top surface situated in the same plane as said rim, a cover providing a third section of said induction passage coextensive with said first and second sections and forming an air intake to said carburetor said cover having a lower horizontal surface contacting both said rim of said body and said top surface of said block.

2. A carburetor according to claim 1 wherein the carburetion block includes an oblique emulsion outlet duct projecting into the second induction passage section.

References Cited by the Examiner UNITED STATES PATENTS 3,076,639 2/ 1963 Szwargulski et al. 261-72 X 3,089,685 5/ 1963 Hennemann et al, 261-72 X 3,109,043 10/ 1963 Carlson et al. 261-72 X FOREIGN PATENTS 501,651 2/ 1939 Great Britain.

HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner.

Claims

1. A CARBURETOR HAVING AN INDUCTION PASSAGE COMPRISING A MAIN BODY, A CONSTANT LEVEL FUEL CHAMBER AND A FIRST SECTION OF SAID INDUCTION PASSAGE IN SAID MAIN BODY, A HORIZONTAL RIM AT THE UPPER END OF SAID MAIN BODY ABOVE THE FUEL LEVEL IN SAID FUEL CHAMBER, A HORIZONTAL BEARING SURFACE PROVIDED IN SAID MAIN BODY BELOW THE FUEL LEVEL AND SURROUNDING THE UPPER END OF SAID FIRST INDUCTION PASSAGE SECTION, A CARBURETION BLOCK IS IN MAIN BODY SEPARATE THEREFROM AND PROVIDING A SECOND SECTION OF SAID INDUCTION PASSAGE COEXTENSIVE WITH SAID FIRST SECTION, FUEL PASSAGES IN SAID BLOCK FOR CONNECTING SAID FUEL CHAMBER WITH SAID SECOND INDUCTION PASSAGE SECTION, A HORIZONTAL ANNULAR SURFACE PROVIDED IN SAID BLOCK AROUND THE LOWER END OF SAID SECOND INDUCTION PASSAGE SECTION, AN INSULATING GASKET INTERPOSED BETWEEN SAID BEARING SURFACE OF THE MAIN BODY AND SAID ANNULAR SURFACE OF SAID BLOCK, SAID BLOCK HAVING A HORIZONTAL TOP SURFACE SITUATED IN THE SAME PLANE AS SAID RIM, A COVER PROVIDING A THIRD SECTION OF SAID INDUCTION PASSAGE COEXTENSIVE WITH SAID FIRST AND SECOND SECTIONS AND FORMING AN AIR INTAKE TO SAID CARBURETOR SAID COVER HAVING A LOWER HORIZONTAL SURFACE CONTACTING BOTH SAID RIM OF SAID BODY AND SAID TOP SURFACE OF SAID BLOCK.