US3480418A - Carburetor - Google Patents

Description

Nov. 25, 1969 A. s. KHACHIJAN ETAL I 3, ,418

CARBURETOR 7 Filed July 19. 1965 2 Shecs-Sheet 1 AL 14 1 1a 35 Nov. 25 1969 A. s. KHAC'HIJAN ETAL 33,430,413

CARBURETOR Filed Ju1y'19, 19 65 I 2 Sheets-Sheet z United States Patent US. Cl. 48-180 Claims ABSTRACT OF THE DISCLOSURE A carburetor having a body with symmetrical curvilinear channels leading from an inlet for fuel-air mixture to an outlet for fuel-air mixture, there being two symmetrical slide valves coupled together and positioned in respective channels for controlling flow of fuel-air mixture from the inlet to the outlet, each slide valve being composed of a fixed diaphragm with shaped slots therein and an adjacent rotatable choke also with slots therein which register with the slots in the diaphragm.

The present invention relates to carburetors with a throttle device used, for example in gasoline engines.

Known at present are gasoline carburetors having a throttle device in the form of an adjustable elliptical choke. Although simple and reliable in operation, said carburetors are not suitable for those gasoline engines which require automatic precision control of speed, since their throttle device is of low response, readil unbalanced in the fuel flow, has an inadequate relationship of passage section in the throttle device to the angle of turn of the choke, and a relatively wide required angle of turn of the choke. The latter circumstance causes excessive bulkiness of the elements connected with the choke coupling, especially when the stroke of said coupling is limited.

All attempts to overcome these disadvantages have so far met with no or little success, whereas we have successfully solved the problem and conceived practical embodiment.

The primary object of this invention is to produce a gas carburetor with a throttle device having precision control of fuel flow at all engine speeds.

Another object of this invention is to relieve the throttle device from the action of dynamic forces from the fuel flow.

It is still another object of this invention to make the coupling elements of the throttle device of compact construction.

As a result, it is possible to materially increase the degree of precision of the engine speed adjustment.

It has now been found that the use of the proposed carburetor makes it possible to use the throttle device of a basic diesel in a gasoline engine without any deterioration of precision automatic speed control.

In accordance with the aforementioned and other objects, this invention contemplates a carburetor which cornprises a body having an inlet and an outlet for a fuel-air mixture, said body further having two channels leading from the inlet to the outlet in symmetrical disposition in said body, and throttle means in said body including two symmetrical slide valves coupled together and positioned in a respective channel for controlling flow of fuel-air mixture in said channels from the inlet to the outlet.

c CC Other objects and advantages of this invention will be understood from the following description and accompanying drawing, wherein:

FIG. 1 shows a gas carburetor of the invention in longitudinal section;

FIG. 2 is a section along line A-A of FIG. 1;

FIG. 3 is a plan view of a diaphragm of the slide valve of the carburetor; and

FIG. 4 is a plan view of the choke of the slide-valve.

The gas carburetor is comprised of a body of three sections, Le, a central section 1, and two equal and symmetrically positioned lateral sections 2, 3. Lateral sections 2, 3 of the body are detachably fixed to central section 1 with studs 4. Central section 1 is connected to the inlet manifold of the engine by outlet branch 5, whose axis lies in the symmetry plane of the body. Inlet branch 6 of central section 1 of the body houses a diffusor 7 into which fuel is fed via pipe 8 and elbow branch 9. At the inlet of branch 6 is installed an air filter 10. The inside cavities of central section 1 and lateral sections 2, 3 of the body form two curvilinear channels 11, 12 beginning at the outlet of the inlet branch 6 and terminating in cavity 13 which is connected to outlet branch 5.

Channel 11 is a mirror reflection of channel 12.

At the outlet of channels 11, 12 is installed a throttle device incorporating two controllable disk slide valves, one of which is a mirror reflection of the other. The slide valves, in turn, comprise diaphragms 15, 16 which are fixed with pins 14 to the body between central section 1 and lateral section 2, 3. Additionally the slide valves comprise chokes 17, 18 which are supported in spaced relation from diaphragms 15, 16 and are rigidly con nected to shaft 19 which is rotatable in needle bearings 20, 21.

Channels 11, 12 and the disk slide valves are positioned symmetrically to each other with regard to the symmetry plane of the body.

Chokes 17, 18 are fixed against turning by keys 22, 23 and are clamped to ring projections 24, 25 of shaft 19 with screws 26, 27.

Diaphragms 15, 16 are constructed as disks with bushes 28, 29 which are internally threaded. In bushes 28, 29 are engaged bolts 30, 31 with nuts 32, 33, which serve as axial stops of shaft 19. By turning bolts 30, 31 the clearances are adjusted between diaphragms 15, 16 and chokes 17, 18.

The disks of diaphragms 15, 16 have shaped slots 34 uniformly distributed along their circumference (FIG. 3).

Chokes 17, 18 are constructed as disks with bushes 35, 36 having shaped slots 37 uniformly distributed along their circumference (FIG. 4) similar to slots 34 in diaphragms 15, 16. Slots 34, 37 are shaped so as to rectify the throttle characteristic and to reduce the torque applied to chokes 17, 18 in the fuel flow and transmitted to the throttle bush.

With a suificient number of slots (eight in number in FIGS. 3 and 4), the required angle of choke turn will be decreased and hence the total mass of the elements of the throttle device will also be reduced.

Fixed by screw 38 to shaft 19, between chokes 17 and 18, is a dog 39, by which shaft 19 carrying disks 17 and 18 is actuated by the engine-speed control device.

The travel of dog 39 is limited by the end of threaded bush 40 and the head of a screw 41 screwed into said bush.

In operation, fuel and air are sucked into the carburetor as a partial vacuum is created in the engine inlet system. In diifusor 7 the fuel is mixed in the air.

The fuel-air mixture flows in two streams via channels 11, 12 from two opposite sides to the throttle device.

Since channels 11, 12 and the disk slide valves are positioned symmetrically to each other with regard to the symmetry plane of the body, whereas the passage sections of both slide valves are equal irrespective of the position of dog 39 and moreover since one slide valve is a mirror reflection of the other, and channel 11 is a mirror reflection of channel 12, chokes 17, 18 will be acted upon by equivalent axial counterforces, and hence the throttle device will acquire the necessary responsiveness.

Depending on the degree to which chokes 17, 18 are rotated by shaft 19, the degree of registry of the slots on the chokes and diaphagm will be controlled and hence a varying amount of fuel-air mixture will pass through the throttle device into cavity 13, wherefrom it proceeds via outlet branch 5 into the engine inlet manifold. The degree to which the passage section through the slots is opened Will depend on the position of dog 19.

Although this invention has been described in connection with the preferred embodiment thereof, modifications and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. A carburetor comprising a body having an inlet and an outlet for a fuel-air mixture, said body further having two channels leading from the inlet to the outlet in symmetrical disposition in said body, and throttle means in said body including two symmetrical slide valves coupled together and positioned in a respective channel for controlling flow of fuel-air mixture in said channels from the inlet to the outlet.

2. A carburetor as claimed in claim 1, wherein each said slide valve comprises a fixed diaphragm and a rotatable choke adjacent the diaphragm, said choke and diaphragm having shaped slots therein which register with one another.

3. A carburetor as claimed in claim 2, wherein said throttle means comprises a rotatable shaft connected to the choke of each slide valve for rotating the same in concurrence, and a dog, on said shaft for rotating the same, to control the throttle means and the flow of the fuel-air mixture.

4. A carburetor as claimed in claim 3, wherein said choke and diaphragm are each of disk shape, said diaphagm including an internally threaded bush and a bolt in said threaded bush serving as an axial stop for said shaft.

5. A carburetor as claimed in claim 1, wherein said body is constituted of a plurality of detachably connected portions, and said channels are curvilinear and are formed by cavities provided in the sections.

References Cited UNITED STATES PATENTS 1,798,317 3/1931 Eaton 48-184 1,999,740 4/1935 Schmidt et a1. 48--184 MORRIS O. WOLK, Primary Examiner M. D. BURNS, Assistant Examiner

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