US2783034A

US2783034A - Control of fuel valve by carburetor throttle

Info

Publication number: US2783034A
Application number: US409708A
Authority: US
Inventors: Maldwyn E Jones
Original assignee: ACF Industries Inc
Current assignee: ACF Industries Inc
Priority date: 1954-02-11
Filing date: 1954-02-11
Publication date: 1957-02-26
Anticipated expiration: 1974-02-26

Description

Feb.A 26, 1957 M, E, JQNES .2,783,034

CONTROL 0F FUEL VALVE: BY CARBURETQR THROTTLE: Filed Feb. 11jl 1954 INVEIVTOR. yMALDWYN EJONES ATTORNEY e' se United Staes Pam O CONTRL F FUEL VALVE BY CARBURETOR Y THRTTLE Maldwyn E. Jones, Ferguson, M0., assigner, by mesne assignments, to ACF Industries, Incorporated, New

York, N. Y., a corporation of New Jersey Application February 11, 1954, Serial No. 409,708

2 Claims.A (Cl. 26150) This invention relates to carburetors and, more spe cifcally, to a novel throttle device for a carburetor which forms a combined means for metering the ow of air and the iiow of fuel.

In the present invention, a fuel metering pin is formed as an Vextension of the throttle shaft, and the shaft is mounted for translation during'rotationvrso as to move the pin into and out of an adjustably positioned orifice. With such a mechanism, given a fuel supply of constant head, ow through the orifice can be regulated directly by throttle rotation.

This invention contemplates a fuel supply which is pressurized so as to deliver fuel to the orifice at substantially a constant head of pressure in 'any position of the carburetor or fuel supply, but the invention is not limited to such a system using pressure. Instead, the orifice may be supplied from a constant level fuel chamber such as in the customary carburetor structures having float bowls.

According to this invention, the carburetor has a mix ture conduit providing a passage of variable area adjacent the fuel nozzle for maintaining a certain range of air velocities in the open positions of the throttle. The fuel nozzle is located in the mixture conduit in a zone controlled by this variable area means.

According to this invention, the variable area means is so constructed las to close the fuel nozzle when the engine is not in operation. In the present invention, this control means is shown in the form of a spring controlled poppet valve, but it is obvious to those skilled in the art that the function of this means may be performed by two separate mechanisms instead of one, and by diaphragm controlled valves instead of by poppet valves. One form of the present invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a sectional view through a carburetor showing the throttle valve in the engine idling position.

Fig. 2 illustrates the same construction with the throttle valve wide open.

Figs. 1 and 2 in the drawings show a carburetor having a body portion 1 containing an inlet 2 to a mixture conduit 3 communicating with an 'air Valve seat 4 which divides the mixture conduit intermediate the air horn 2 and the throttle body 5. Cast integrally with the body 1 is a boss 7 extending into the mixture conduit 3. Boss 7 is bored centrally to provide a guide for valve stem 8. The valve 9 on stem 8 rests on the seat 4 and controls the passage between the air horn and the throttle body. Valve 9 is fixed to the stem 8, the latter of which has an extension 10 received within a guide in boss 11 formed integrally with cap 12 which is suitably secured in one side ofthe mixture conduit. A calibrated spring 13 urges the valve 9 towards its seat 4.

Throttle body 5 is suitably aperturedat `15 to provide a journal bearing for one end of throttle shaft 16. vThe opposite side of throttle body 5 is threaded at 17 for engaging corresponding threads on the opposite end of the throttle shaft 16. Integral with the shaft 16 is a metering pin 18, which projects into a metering orifice 19 threadedly engaging a bore 20 in the body 1. An exten sion in the form of a stem 21 is formed on the metering orifice 19 provided with a handle 22 forA adjusting the relationship between the metering orifice 19 and the metering pin 18. The stem 21 is provided with a packing gland 23 to prevent leakage around the stern.

The body 1 of the carburetor is also provided with a threaded inlet 25 for connection with a source of fuel under pressure. The inlet 25 communicates directly with the orifice 19 which, in turn, is provided with Huid passages 26 communicating directly with a fuel nozzle 27 which leads to valve seat 4. The fuel entering at the supply connection 25 is metered by the pin 18 before entering the orice which connects directly with the fuel nozzle.

On the throttle shaft 16 is a throttle valve 30 recessed at 31 to provide for lateral movement of the throttle shaft 16 by the thread 17, and the range of opening movement of this valve is controlled by a fixed stop 31 when the throttle is wide open, and an adjustable stop 32 for the idling position. A lever 33 is fixed to the throttle shaft 16 and `carries the

stops

31 and 32. Lever 33 is biased to its closed or idling position by a torsion spring 34 engaging the lever 33 and a fixed stop on the throttle body 5.

The air horn 2 rotatably mounts a shaft 35 carrying the choke valve 36, which may be manually or automatically controlled, as desired.

Operation The idling speed of the engine can be controlled by adjustment of the stop 32, which has a tapered end engaging the throttle body 5. As the screw 32 moves toward the throttle body, its tapered end will alter the minimum closed position of the throttle valve 30. The position of the throttle valve 30 determines the fuel mixture by varying the clearance between the tapered meter ing pin 18 in the metering orifice 19. Adjustment of the handle 22 will therefore determine the amount of fuel supply to the fuel nozzle 27 to form the proper mixture. Once thisv setting has been achieved, then the amount of lead provided in the thread 17, together with the proper configuration for the metering pin 18 will determine the amount of opening inthe metering orifice for each open position of the throttle valve 30.

As the throttle is opened, threads 17 will move the throttle shaft 16 to the right, and the throttle valve 30 is recessed lat 31 to permit this movement. Wide open position of the throttle is limited by the contact of the stop 31 with the throttle body 5.

In Fig. l, the valve 9 is shown seated, which will be generally the case when the engine is not in operation. In this position the valve 9 seals the fuel nozzle 27 so as to prevent leakage of fuel from the nozzle 27 when the engine is not in operation. Such a feature is desirable to prevent continued ow of fuel under such circumstances, regardless of carburetor position or the presence of fuel under pressure connected to the supply connection `25. When the engine is idling, valve 9 will be spaced slightly from the seat 4 either intermittently or continuously, which will allow fuel to escape from the fuel nozzle 27 into an air stream of relatively high velocity. This will be beneficial in thoroughly mixing the fuel and air, and help to maintain some of the fuel, at least, in suspension as it passes through the recess 31 of the throttle valve 30.

In Fig. 2, the throttle valve 30 is shown wide open and the valve 9 in fa position to pass suf`n`cient air for the high speed operation of the engine. In this position of the valve 9, the nozzle 27 is subjected to high velocity 3 irow `around 'the valve 9 to aid in atomization of the fuel.

It is possible that the valve 9 can assume different positions for any position of the throttle 30, depending, of course, upon the engine demand for -fuel mixture. It Vis, therfore,- a Vfuel Acontrolacting to modulate the nete'ring function ofthe pin 18 inthe orifice 19.

`Itis contemplated that thisstructure may bemdied by `those `skilled in the art in many; ways -without departing from the scope lof -the invention as defined by the appended claims.

I claim:

`l. In `a carburetoigthe combination of an air horn including an 'air inlet passage, a throttle body for -said carburetor having 'a 4mixture conduit in offset parallel relation to said air horn passage, a sliot'passage exte11din'g at an angle and connecting said air-'horn passage and said mixture conduit, thereby forming -an abrupt turn in the airflow path through said carburetor, a fuel nozzle in said mixture conduit in the zone of high velocity airow effected by the abrupt turnin said airflow 4pathya 4source of -fuel `under substantially constant'pressureconnected to said fuel nozzle, a variable fuel metering restriction in said connection, and means adapted to close both said fuel nozzle and said short connecting passage, said means being responsive to airow in said mixture conduit for con trolling the fuel pressure downstream of said fuel metering restriction.

2. In a carburetor, the combination of an air horn havingan air inlet passage, a throttle body for said'carburetor having a mixture conduit in offset parallel relation to said air horn passage, a short passage extending at an angle and connecting said air horn passage and said mixture conduit, thereby forming an abrupt turn in the airflow path, a fuel nozzle located in said mixture conduit in the zone of high velocity airflow effected by the abrupt turn in the airilow path, a source of fuel under substantially constant pressure connected to said fuel nozzle, a variable fuel metering restriction in said connection, and means responsive to airflow located adjacent said nozzle to confine the airow path to the wall of said mixture conduit to produce a high velocity at the abrupt turn in the airflow path when open, and to shut off the flow of fuel from said nozzle when closed.

References Cited in the file of this patent UNrTED STATES PATENTS 635,166 Hay Oct. 17, 1899 976,237 Westmacott Nov. 22, 1910 1,181,356 Thompson etal May 2, 1916 1,718,735 Eiker June 25, v1929 2,167,892 Kent et al. i Aug. l, 1939 2,552,465 Spranger May 8, 1951 2,562,826 Sharp July 31, 1951