RU196163U1 - Two-chamber carburetor of an internal combustion engine - Google Patents

Abstract

The utility model relates to engine building, in particular, to the power systems of carburetor internal combustion engines, and directly to the design of the atomizer of the accelerator pump of a two-chamber carburetor.

A two-chamber carburetor of an internal combustion engine having two parallel main air paths with a diffuser system with a drive throttle 8 located in each of them, mounted on a rotary shaft 9 perpendicular to the longitudinal axial line NN of the main air path, containing a spray gun 10 of the accelerator pump, made in the form of a cast parts installed in the upper part of the body of the float chamber 1 of the two-chamber carburetor in the vertical discharge channel 11, parallel to the axis NN of the main the air path of the primary chamber 2 of the two-chamber carburetor having a hollow cylindrical body 12 connected to a circular inclined channel 13 with a large diameter hole and a calibrated metering outlet 15 of the nozzle 14 brought into the main air path of the primary chamber of the two-chamber carburetor in the upper part of the entrance cavity 5 of the diffuser system carburetor so that the spray nozzle is located above the confuser 3 of the large diffuser, and the plane drawn through the axis MM of the housing 12 of the spray gun 10 and the axis inclined to of the angular channel passes vertically through the small diffuser 7, the nozzle nozzle channel is made in such a way that the axis RR of the calibrated nozzle hole is inside a straight circular cone with its apex at the exit point of the calibrated hole from the nozzle of the nozzle with an apex angle (cone opening angle) of 6 degrees and with the QQ axis of the cone located in a plane passing through the axis MM of the atomizer body and the axis of the inclined circular channel at an angle of 15 degrees to the axis MM of the atomizer body, with the center of the calibrated outlet hole at a distance of "T" from 13 to 14 mm relative to the axis of the spray gun body and at a distance of "H" from 2.3 to 3.0 mm relative to the installation plane of the spray gun body, with the plane drawn through the axis MM of the spray gun body and the axis of the inclined round channel, passes vertically through a small diffuser at a distance "S" from the axis of the main air path, equal to (0.26 - 0.44) x D, where "D" is the outer diameter of the small diffuser.

In this case, the two-chamber carburetor can be made with a sprayer, the body of which is connected to two round inclined channels with nozzles having each calibrated outlet, with the possibility of symmetrical fuel injection into both main air paths.

Using the utility model allows to increase the stability of the engine during acceleration after a sharp opening of the throttle valve, to improve its dynamic and environmental performance by improving the quality of mixture formation using the optimal direction of fuel injection with an accelerator pump nozzle.

Description

The utility model relates to engine building, in particular, to the power systems of carburetor internal combustion engines, and directly to the design of the atomizer of the accelerator pump of a two-chamber carburetor.

From a public source: Carburetors "Ozone", Device, operation, repair: Compiled by S.N. The cellar. - M .: Publishing house Third Rome, 2000. - 64 p., Table, ill., The design of a two-chamber carburetor with an accelerator pump atomizer, made in the form of a casting part and installed in the connector between the cover and the body of the carburetor float chamber with a hole outlet, is known spray nozzles into the main air path of the carburetor and the direction of injection of the fuel stream along the air stream with a slight inclination to the axis of the main air path so that the fuel stream during injection passes near the wall of the large diffuser viscous section.

From a public source: Casedorf J. Carburetors of foreign cars. Device, adjustment, repair: Per. with him. Ed. Cand. Tech. Science A.S. Tyufyakova. - M.: Publishing House "Behind the Wheel", 1998 - 192 p. Il., it is known to design a Zenit 35/40 INAT dual-chamber carburetor with sequential opening of throttle valves, which has a primary chamber accelerator pump with a fuel jet in the gap between the closed throttle and the carburetor mixing chamber wall and a secondary chamber accelerator pump with a jet direction fuel to the area of the lower part of the large diffuser near the carburetor wall.

From the patent RU23464 of 01/08/2002, IPC F02M 39/00, a carburetor of an internal combustion engine is known, in which the axis of the outlet of the atomizer is made at an angle to the longitudinal axis of the main air channel and passes through the gap between the throttle in the closed position and the wall of the main air channel for dosing accuracy fuel, eliminating “failures” in acceleration modes and increasing engine stability.

The disadvantage of this design is that the influence of the processes of mixture formation in the carburetor, in particular, the processes of droplet formation and evaporation of fuel, on the conditions for the formation of a combustible mixture in the intake tract and its dependence on the direction of fuel injection by the accelerator pump nozzle are not fully taken into account. This technical solution is considered as the closest analogue.

It is known that a carburetor engine is an engine with external mixture formation, that is, the formation of a combustible mixture begins up to the engine cylinders in the carburetor and continues in the intake manifold.

The quality of mixture formation is determined by the indicator of the uniform distribution of the mixture across the cylinders, both by the uniformity of the composition and by the homogeneity of the structure of the mixture falling into each cylinder. The best indicator of the distribution of the mixture over the cylinders is achieved with maximum evaporation of the fuel and finding the rest of its amount in a finely dispersed state in the form of small drops.

It is also known that fuel evaporation improves with an increase in the evaporation surface, an increase in the temperature of the mixture and a decrease in absolute pressure, that is, with an increase in vacuum in the volume of the mixture.

An increase in the evaporation surface is achieved by crushing the fuel into a large number of small droplets.

An increase in the temperature of the mixture is achieved by heating it, which, in order to avoid losses in filling the engine cylinders, is usually carried out by local heat supply due to the heating of the inlet pipe under the carburetor.

The finely dispersed state of the mixture is ensured by an increase in the difference between the relative speeds of the fuel and the air flow, and the highest flow rates and the greatest rarefaction in the large carburetor diffuser are observed in the narrow section in its central part at the level of the air flow exit from the small diffuser.

Thus, in order to improve the fragmentation of the fuel jet into droplets and to improve the evaporation of the fuel leaving the atomizer of the accelerator pump, it is necessary that the fuel enters the zone of high air flow rates and high vacuum, that is, as close as possible to the center of the air flow in the main air path, and also unhindered into heated sections of the intake manifold.

Indirect indicators of the qualitative distribution of the mixture across the cylinders are the good speed properties of the car, that is, the ability of the car to quickly increase speed when starting up or shifting the steps in the gearbox to a given speed, with allowable emissions of harmful substances from the exhaust gases when testing the car on the European driving cycle in in accordance with GOST R 41.83-2004 (UNECE Regulation N 83) with the minimum possible fuel supply through the atomizer of the accelerator pump.

It was experimentally established that the indicated performance of the car is achieved with the direction of the fuel jet injected by the accelerator pump, in which it passes through an opening with a diameter of 5 mm, made at a distance of 20.5 mm from the axis of the atomizer body of the accelerator pump in a 3 mm thick template plate, installed at a distance of 28.5 mm from the installation plane of the atomizer body.

The problem solved by the claimed utility model is to increase the stability of the engine during acceleration after a sharp opening of the throttle valve, to improve its dynamic and environmental performance by improving the quality of mixture formation using the optimal direction of fuel injection with an accelerator pump nozzle.

The technical result achieved by the implementation of the claimed utility model is that in a two-chamber carburetor of an internal combustion engine having two parallel main air paths with a diffuser system with a drive throttle located in each of them, mounted on a rotary shaft perpendicular to the longitudinal axial line of the main the air path containing the accelerator pump atomizer, made in the form of a cast part, mounted in the upper part of the car float chamber body a borator in a vertical discharge channel parallel to the NN axis of the main air path of the carburetor primary chamber, having a hollow cylindrical body connected to a circular inclined channel with a large diameter hole and a calibrated metering outlet for the nozzle brought into the main air path of the carburetor primary chamber in the upper part of the entry cavity carburetor diffusers so that the nozzle of the atomizer is located above the confuser of the large diffuser, and the plane drawn through the axis of the MM body the nozzle mustache and the axis of the inclined circular channel pass vertically through the small diffuser, and the nozzle channel of the nozzle is designed so that the RR axis of the calibrated nozzle opening is inside a straight circular cone with its apex at the exit point of the calibrated hole from the nozzle of the nozzle with an angle at the apex (apex angle cone) 6 degrees and with the QQ axis of the cone located in a plane passing through the axis MM of the spray gun body and the axis of the inclined round channel, at an angle of 15 degrees to the axis MM of the spray gun body, with By increasing the center of the calibrated outlet at a distance “T” from 13 to 14 mm relative to the axis of the atomizer body and at a distance “H” from 2.3 to 3.0 mm relative to the installation plane of the atomizer body, the plane drawn through the axis MM of the atomizer body and the axis of the inclined circular channel passes vertically through the small diffuser at a distance “S” from the axis of the main air path equal to (0.26 - 0.44) x D, where “D” is the outer diameter of the small diffuser.

In this case, the two-chamber carburetor can be made with a sprayer, the body of which is connected to two round inclined channels with nozzles having each calibrated outlet, with the possibility of symmetrical fuel injection into both main air paths.

In addition, each of the two round channels of the atomizer can have calibrated nozzle outlet openings, the diameters of which differ from each other.

The proposed utility model is illustrated in the drawings.

FIG. 1 - Top view of the plan for the installation of the accelerator pump atomizer in the housing of the carburetor float chamber;

FIG. 2 - a sectional view A-A along the installation plane of the accelerator pump atomizer in the carburetor main inlet (carburetor cover and intake pipe are not shown) with an additional image of the template for checking the direction of fuel injection through the accelerator pump atomizer;

FIG. 3 - Top view in plan of the accelerator pump atomizer;

FIG. 4 - Sectional view BB of the accelerator pump atomizer;

FIG. 5 is a view of an enlarged fragment of a section BB of the accelerator pump atomizer, view B. FIG. 4;

FIG. 6 - Top view in plan of the accelerator pump atomizer according to the embodiment with two nozzles;

Fig. 7 is a sectional view A-A along the installation plane of the accelerator pump atomizer in the carburetor main inlet during operation of the atomizer with a fuel flow line taking into account the effect of air flow on a running engine (carburetor cover and intake pipe are not shown).

A two-chamber carburetor of an internal combustion engine having two parallel main air paths comprises a body of the float chamber 1, including a part of the main air path of the primary chamber 2 with a diffuser system. The large diffuser 3 is molded integrally with the body of the float chamber 1. The confuser 4 of the large diffuser 3 is connected to the entry cavity 5 of the carburetor diffuser system.

In the vertical grooves 6 of the entry cavity 5, a small diffuser 7 is installed with an outer diameter D, which is rigidly fixed in the housing of the float chamber 1 of the two-chamber carburetor with a spring. In addition, the two-chamber carburetor contains a primary throttle drive chamber 8 mounted on a rotary shaft 9 perpendicular to the longitudinal axis NN of the primary air path of the primary chamber 2, as well as an accelerator pump sprayer 10 located in the upper part of the float chamber 1 and installed in the vertical discharge channel 11 of the accelerator pump of the two-chamber carburetor, parallel to the axis NN of the main air path of the primary chamber 2, into the recess with a groove defining the direction of forward Fuel ska.

The sprayer 10 is made in the form of a molded part, consisting of a hollow cylindrical body 12 connected to an inclined circular channel 13 and a nozzle 14 having a calibrated outlet 15 output to the upper part of the inlet cavity 5 of the diffuser system of the main air path of the primary chamber 2 of the two-chamber carburetor in such a way that the nozzle 14 is located above the confuser 3, and the plane drawn through the vertical axis MM of the housing 12 of the sprayer 10 and the inclined axis of the channel 13, corresponding to the theoretical calculated plane the fuel injection from the atomizer 10 passes vertically through the small diffuser 7 at a distance S from the axis NN of the main air path of the primary chamber 2 equal to (0.26 - 0.44) x D, where D is the outer diameter of the small diffuser 7. Channel 13 and the nozzle 14 of the sprayer 10 is made outside streamlined to create the least resistance to air flow.

The calibrated outlet 15 of the nozzle 14 is made at an angle to the axis MM of the body 12 of the sprayer 10 so that its axis RR is inside a straight circular cone with a vertex at the exit point of the calibrated hole 15 of the nozzle 12 of the sprayer 10 with the angle at the apex (angle of apex) cone) 6 degrees, and the axis of the cone QQ is located in the theoretical calculated plane of the fuel injection passing through the axis of the body of the MM gun and the axis of the inclined channel, at an angle of 15 degrees to the axis MM of the gun body. The exit point of the axis RR of the calibrated hole 15 of the nozzle 14 is located at a distance "T" from 13 to 14 mm from the axis MM of the housing 12 of the spray gun 10 and at a distance of "H" from 2.3 to 3.0 mm relative to the mounting plane 16 the housing 12 of the sprayer 10. For the formation of a given direction of fuel injection with the required supply and excluding the possibility of excessive pressure increase in the accelerator pump system, the calculated value of the internal diameter "d" of the calibrated hole 15 of the nozzle 14 is 0.3-0.5 mm, and the length 5 8 mentioned diameters.

These dimensions are selected empirically to ensure a given direction of fuel injection under the design pressure at which the fuel stream is guaranteed to pass through the hole in a special template (described above).

There are various options for improving the proposed utility model.

One of them involves the implementation of a sprayer in a two-chamber carburetor, the body of which is connected to two circular inclined channels with nozzles having each calibrated outlet, with the possibility of symmetrical fuel injection into both main air paths.

In addition, each of the two round inclined channels of the atomizer can have calibrated nozzle outlet openings, the diameters of which differ from each other.

The work of the proposed utility model is as follows.

The movement of the car, especially in urban conditions, is accompanied by engine operation in steady and unsteady modes. In steady-state modes, the fuel is dosed in the carburetor by the operation of the main and transitional dosing systems, and each mode has its own fuel supply through the nozzles. The transition from one steady state to another is carried out when the throttle position is changed. Acceleration of a car (engine) is the most difficult unsteady mode of operation and occurs when the throttle is suddenly opened. In this case, a sharp depletion of the mixture entering the engine cylinders occurs due to the inertia of the fuel supply system, and mainly because of a violation of the mixture formation in the engine intake system caused by an increase in pressure and a corresponding deterioration in fuel evaporation. To compensate for this phenomenon, additional fuel is supplied to the main air path of the carburetor using an accelerator pump.

The necessary enrichment of the mixture is carried out by directed injection of an additional metered portion of fuel into the air flow passing through the main air path of the primary chamber 2 of the two-chamber carburetor in the direction specified by the calibrated hole 15 of the nozzle 14 along its R-R axis. Getting into the zone of high speeds and low rarefaction behind the small diffuser 7 near the N-axis of the main air path of the primary chamber 2, the fuel jet begins to crumble into droplets, and the fuel evaporates through the calibrated hole 15 of the nozzle 14 of the sprayer 10 of the accelerator pump.

Due to the evaporation in the main air path of the primary chamber 2 of gasoline supplied by a two-chamber carburetor, the temperature of the prepared mixture falling into the mixing chamber 17 of the carburetor decreases and accordingly the temperature of all structural elements in the mixing chamber 17 decreases, including the throttle valve 8 and the throttle valve shaft 9.

The geometric fuel injection line 18, drawn along the RR axis of the calibrated hole 15 of the nozzle 14, passes through the throttle valve 9, but due to the air flow, the injected fuel path 19 is curved and actually the fuel supplied through the accelerator pump atomizer 10 passes by the roller 9 throttle valve 8 and enters directly into the intake manifold.

The direction of injection of additional fuel given by the design of the sprayer 10, supplied through the nozzle 14 of the sprayer 10 of the accelerator pump, during acceleration of the car (engine) ensures its crushing into small droplets, intense evaporation, eliminates its contact with the cooled metal parts of a two-chamber carburetor, including the throttle roller the shutter 9 of the primary mixing chamber 17, and allows, together with the total flow of the mixture to get directly into the inlet pipe, which has additional bottom heating, where the final mixture formation is carried out, and thereby ensures an optimal distribution of the mixture of homogeneous composition over the engine cylinders, thereby increasing the stability of the engine during acceleration after a sharp opening of the throttle valve 8, improving its dynamic and environmental performance by improving the quality of mixture formation using the optimal direction fuel injection nozzle 14 accelerator pump.

The selection of the sprayer parameters was carried out on a non-motorized stand and a car on samples of a two-chamber carburetor manufactured in mass production.

Claims (3)

1. Two-chamber carburetor of an internal combustion engine having two parallel main air paths with a diffuser system with a drive throttle located in each of them, mounted on a rotary shaft perpendicular to the longitudinal axial line of the main air path, containing an accelerator pump atomizer made in the form of a cast part, installed in the upper part of the body of the float chamber of a two-chamber carburetor in a vertical discharge channel parallel to the axis of the main air about the path of the primary chamber of the two-chamber carburetor having a hollow cylindrical body connected to the inclined channel with a large diameter hole, conjugated at an angle with the calibrated metering outlet of the nozzle brought into the main air path of the primary chamber of the two-chamber carburetor in the upper part of the entrance cavity of the diffuser system in such a way that the output of the calibrated metering hole is above the confuser of the large diffuser, and the plane drawn through the axis of the atomizer body and the axis on of the inclined channel, passes vertically through the small diffuser at a distance from the axis of the main air path of the primary chamber of the two-chamber carburetor, characterized in that the plane drawn through the axis of the atomizer body and the axis of the inclined channel passes vertically through the small diffuser at a distance from the axis of the main air path of the primary chamber a two-chamber carburetor at (0.26 - 0.44) x D, where D is the detecting diameter of the small diffuser, and the axis of the calibrated nozzle hole is inside a straight circular cone with an apex at e the exit of the calibrated hole from the nozzle of the nozzle, with an angle at the apex (cone angle) of 6 degrees and with the axis of the cone located in a plane passing through the axis of the atomizer body and the axis of the inclined channel, at an angle of 15 degrees to the axis of the atomizer body, the exit point the axis of the calibrated nozzle opening is located at a distance of 13 - 14 mm from the axis of the atomizer body and below the installation plane of the atomizer body at a distance of 2.3 - 3.0 mm. 2. A two-chamber carburetor according to claim 1, characterized in that the atomizer body is connected to two round inclined channels with nozzles having each calibrated outlet, with the possibility of symmetrical fuel injection into both main air ducts. 3. The two-chamber carburetor according to claim 2, characterized in that each of the two round inclined channels of the atomizer has calibrated nozzle outlet openings, the diameters of which differ from each other.

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