Technical Field

The invention relates to a carburetter for gasoline engines, provided with air-inflow, a main nozzle, a supply channel for idle running, furtheron with a carburetter choke having a throttle valve for regulating the quantity of fuel/air mixture, as well as an induction manifold is provided for.

Background Art

With carburetters for gasoline engines the primary require¬ ment lies in that in course of idle running a relatively concentrated mixture could be produced which establishes equal idle running without superfluous fuel consumption, in addition, in state of fractional load the mixture pro¬ portion should comply with the most favourable specific consumption, as required by the motor. A further, equally important requirement lies in, that by full opening the throttle valve proper concentration of mixture should en¬ able maximal performance and sudden throttling and short- lasting mixture concentration should result in elimination of temporary disturbances in mixture formation, simul- taneously properly concentrated mixture could be obtained, when starting.

It has been tried to solve the aforementioned tasks by means of different structural solutions. With the majority of carburetters mixture of fuel and air providing for the number of revolutions needed for idle running has been achieved by means of a separate nozzle, through the channel by-passing the throttle valve. Generally, the supply channel is arranged asymmetrically in respect to the axis of the throttle valve, as a consequence, air is flowing with a

relatively lower speed, production of mixture will be uncomplete, in addition, in case of fractional load continuous depression may be observed, consequently, mixture will be forwarded to the engine superfluously.

For producing more concentrated mixtures needed for an increased performance, generally a surplus jet nozzle, so-called "performance-nozzle" used to be applied, which injects a' surplus of fuel in course of maximal throttling into the mixing choke. Performance-nozzle used to be put into operation from the axis of the throttle valve by means of a mechanically actuated valve. The drawback of said solution lies in, that the performance-nozzle will be started but at a maximal throttling, furtheron, it is considered as disadvantageous that actuation requires complicated control means involving the possibility of frequent failures.

Generally short-lasting disturbances in mixture production accompanying acceleration used to be eliminated by means of separate auxiliary systems. Either accelerating pumps with a piston are used, or a plularity of bores are formed in the idle running system which are communicating with the mixing choke of the carburetter.

Disadvantageous characteristic of the accelerating pump with the piston lies in the losses due to abrasion, as well as increased probability of failure due to the inserted separate movable unit.

In addition, with the presently used constructions dia¬ meter of the main nozzle is selected so, as to assure the delivery of the maximal quantity of fuel. Accordingly, when using nozzles with a considerable transmittance in course of fractional loadings unnecessarily fuel

consumption may occur.

Furtheron, owing to the unsatisfactory mixture of gasoline and air, as well as to the unsatisfactory combustion" of fuel exhaust gases will contain toxic combustion products, in particular carbon monoxide, which arriving into the atmosphere result in a considerable air contamination with increasing car traffic.

Accordingly, the aim of the invention is to develop a carburetter for gasoline engines which solves the tasks of the cold-starter, temporary mixture production and in case of increased performances, the task of the concentrating device, additionally enables savings in fuel consumption, simultaneously reducing air contamination.

Disclosure of Invention

The invention is based on the recognition, in so far as the aim set can be achieved by taking four technical measures - structural changings - in the system of the carburetter for gasoline engine, while the interactions between the structural changes are completing resp. reinforcing each other.

With the carburetter for gasoline engines according to the invention the supply inflow-channel for idle running is arranged symmetrically in respect to the axle of the throttle valve and as in consideration that in case of idle running a more perfect mixture of air and fuel can be obtained.

Furtheron, in case of reduced fractional loads, as the device in idle running is staying under a continuous de¬ pression, due to the more perfect admixture of air and fuel adequate mixture will be delivered, while this mixture will

be added to the delivery effect of the main nozzle being in operation.

By virtue of said effect main nozzles with reduced trans- mittance can be used.

In accordance with the invention diameter of the main nozzle has been dimensioned for the least quantities to be delivered, accordingly, the diameter can be smaller by 25-30 % in comparison to usual dimensions. Application of nozzles with a smaller diameter - in addition to the preferred arrangement of the supply channel for idle running - can be achieved by the fact, that before the mixing choke an accelerating throttle valve is inserted into the apparatus, which assured - in case of acceleration - the higher depressio by means of the adaquate control. At last, an insert en¬ hancing atomization is inserted into the induction manifold, promoting better admixture of air and gasoline, atomization of gasoline drops and thus resulting in better combustion.

Accordingly, the invention relates to a carburetter for gasoline engines, provided with air-inflow, a main nozzle, a supply channel for idle running, furtheron, with a carburetter choke having a throttle valve for regulating the quantity of fuel/air mixture, as well as an induction manifold is provided for.

The invention can be characterized in that the inflow channel for idle running is arranged symmetrically in respect to the axis of the throttle valve, as well as the diameter of the main nozzle is less by 25 to 30 % in comparison to usual dimensions. Furtheron, before the main nozzle an accelerating valve is arranged, the axis of which being connected to an electromagnet, which again is connected to two signal transmitters arranged on the cam disc on the axis

of the throttle valve. In- the induction manifold an insert is arranged for improving atomization.

In a preferred embodiment of the carburetter according to the invention one of the signal transmitters on the cam disc having been arranged on the axis of the throttle valve is connected to the electromagnet through an electronic control unit.

Brief Description of Drawings

The invention will be described in details by means of a preferred embodiment, by the aid of the drawings enclosed, wherein: Fig.l sectional view of the carburetter according to the invention, Fig.2 the two signal transmitters and the cam disc on the axis of the throttle valve, Fig.3 block schematic of the circuit arrangement of the signal transmitters, the electromagnet and the electronic control unit, Fig.4 sectional view of the induction manifold and the cylinder head with the insert improving atomiza¬ tion, Fig.5 the vertical section of the insert for improving atomization, Fig.6 horizontal section of the insert improving atomization.

Best Mode of Carrying Out the Invention

In case of the embodiment - as illustrated in the figures - the carburetter according to the invention consists of the inflow channel 1 for idle running, the throttle valve 4, the main nozzle 2 communicating with the mixing choke 3.

s it becomes obvious from the figure, in accordance with the direction of suction the accelerating valve 5 is arranged before the main nozzle 2, while the axis of said accelerating valve is connected with the anchor of the electromagnet 6 in a way not detailed here.

Fig.2 illustrates the cam disc 7 installed onto the axis of the throttle valve 4, in case of a smaller turn the signal transmitter I will be actuated, while a larger turn actuates the signal transmitter II.

Fig.3 illustrates the block schematic and scheme of electric control. In a way known in itself, the signal transmitter I starts the electronic control unit 8, which will be simul- taneously controlled by the revolution number of the motor. At a proper r.p.m. the electronic control unit 8 actuates the electromagnet 6 which again opens resp. closes the accelerating valve 5.

Signal transmitter II will be actuated at greater loads, at a larger turn of the cam disc, in this case operation of the signal transmitter will be overbridged.

In Fig.4 the insert 9 for improving atomization is shown, having been arranged in the induction manifold 11. Figs 5 and 6 show the two sectional views of the insert 9 for promoting atomization. Diverting dams 10 with a special profile are cutting the way of the mixture flowing in direc¬ tion of the cylinder, thereafter cut streams are allowed to impact on one another in accordance with their special formation. As a consequence, velocity of the mixture flowing in the induction manifold will be approximately doubled in the insert 9 improving atomization, accordingly, mixture streams impacting with a high velocity on one another in- crease fineness of atomization i.e. improve quality of the

mixture. Generally inserts improving atomization increase suction resistance and weaken charge grade of the cylinders. At the same time the insert according to the invention for improving atomization increases but to a minimal extent suction resistance, as it occupies but a short section of the induction manifold.

When the carburetter is actuated, the throttle valve 4 is in a closed state. Now, only an utmost small cross- section is left free, so - inspite of minimal air delivery - considerable depression arises in the inflow channel 1 for idle running. Now, as the inflow channel 1 for the idle running is arranged symmetrically in respect to the axis of the throttle valve, air velocity will be here the highest, as a consequence mixture production will be far better. Furtheron, with small partial loads this mixture will be added to the mixture delivered by the main nozzle.

The main nozzle 2 with a less permeability prevents that at the partial load of the motor the mixture should not be overconcentrated, that means no superfluous fuel should be added.

In case of a sudden acceleration, when opening the throttle valve 4 to a slight extent only, the cam disc 7 on the axis of the throttle valve 4 actuates the signal transmitter I, which again actuates the electromagnet 6 closing the accelerating valve 5.

Now, in the mixing choke 3 depression increases, while throug the main nozzle 2 with reduced permeability more concentrated mixture will be delivered, accordingly performance increases too. The electronic control unit 8 known in itself and controlled by the revolution number of the motor disconnects automatically the electromagnet 6 in the range between 2000

and 3000 r.p.m., thus opening the accelerating valve 5.

In case of a permanently higher load, when the throttle valve 4 is opened at a larger angle, the cam disc 7 actuates the signal transmitter II, which again connects the electro¬ magnet 6 and thus the accelerating valve 5 will be closed. Now, in the mixing choke 3 depression will be repeatedly high, the mixture will be more concentrated, in such a manner fuel quantity needed for a higher performance stays at disposal. Accelerating valve 5 will be closed as long, as the cam disc 7 is kept in an angular position needed for increased throttling by the throttling valve 4. When actuati the signal transmitter II, the eJectronic control unit 8 is kept out of operation.

With full gas-feeding, the snuffle valve known in itself (not illustrated here) is opened, air arriving into the induction manifold prevpnts OVPΓconcentration.

At last, the insert 9 arranged in the induction manifold 11 improves atomization and promotes better admixture, thus yielding more perfect combustion in the cylinder space. As a consequence, quantity of toxic substances, mainly CO contained in exhaust gas will be less, simultaneously quantity of incombustible hydrocarbons can be reduced.

Due to the structural solutions applied, the carburetter according to the invention has a simplified construction. System of idle running became more simple, separate concent- rating means, cold starter and means for producing temporary mixtures could be omitted. Due to proper production of mix¬ ture and by the virtue of improved combustion requirement of fuel of the gasoline engine will be less, environmental contamination can be reduced, consumption of lubricants will be considerably less. Lubricant will be less contaminat

accordingly, quality will be preserved for a longer period.

Accordingly, technical measures according to the invention increase - as a final result - efficiency of the gasoline motor.