RU2144999C1 - Carburetor for gasoline internal combustion engine - Google Patents

Abstract

FIELD: manufacture of engines; carburetor systems and central fuel injection systems of internal combustion engines. SUBSTANCE: carburetor of internal combustion engine has housing with throttle valve, fuel metering unit and mixing chamber with boundary turbolators for fuel-and-air mixture. Turbolators are made in form of recesses of wedge-shaped section having semioval shape in plan and regularly arranged on surface of mixing chamber wall. Smaller axis of semioval is first one in way of flow and is oriented perpendicularly relative to direction of flow. While passing the section with recesses, boundary flow of fuel-and-air mixture is additionally turbulized, thus enhancing homogeneity of fuel-and-air mixture. EFFECT: enhanced economical efficiency; reduced toxicity of waste gases of engine. 3 dwg

Description

 The present invention relates to the field of engine manufacturing and can be used to improve fuel economy and toxicity of gasoline engines.

 Known devices for mixture formation (carburetor or with gasoline injection) in internal combustion engines containing vortex-forming elements to obtain a homogeneous mixture. These elements create a volumetric or wall turbulization of the air-fuel mixture in the mixing chamber section (US Pat. No. 4,295,458, 4,463,742, 4,715,354; Australian Pat. No. 509,485; AS USSR 1629585 and others).

 Common disadvantages of these devices are the complexity of the design and the increased aerodynamic drag created by the vortex-forming elements in the mixing chamber. These disadvantages do not allow the full use of volumetric and wall turbulence of the flow for homogenization of the air-fuel mixture in order to increase fuel economy and reduce the toxicity of engine exhaust gases.

 A device for mixing in a gasoline engine is known, including a housing with a throttle valve, a fuel metering unit, and a mixing chamber with wall turbulators of the air-fuel mixture in the form of transverse grooves made on the wall surface of the mixing chamber (US Pat. No. 4,215,663, MKI F 02 M 29/00 )

 This design of the device does not significantly increase fuel economy and reduce the toxicity of engine exhaust gases, since turbulators made in the form of transverse grooves on the wall of the mixing chamber do not create intensive turbulization of the wall layer of the air-fuel mixture, but only give a wavy character to the movement of the fuel film along the wall of the mixing chamber .

 The purpose of the invention is to improve fuel economy and reduce the toxicity of engine exhaust gases by increasing the degree of homogenization of the air-fuel mixture.

 This goal is achieved by the fact that in the mixture-forming device for a gasoline internal combustion engine, including a housing with a throttle valve, a fuel injection unit, a mixing chamber with wall turbulators of the air-fuel mixture, the latter are made in the form of wedge-shaped recesses having a half-shaft shape in plan, arranged orderly on the surface the walls of the mixing chamber, with the minor axis semi-axis placed first upstream and oriented perpendicular to the direction of flow.

 An analysis of the patent and scientific and technical literature showed that such an improvement of the device for mixture formation in a gasoline engine is unknown.

 In FIG. 1 shows the proposed design for a central gasoline injection system. The device includes a fuel injection unit - an electromagnetic nozzle 1 installed in a special socket in the upper part 2 of the housing. The latter, in addition to the upper part 2, also includes the lower part 3 containing the throttle valve 4 and the mixing chamber 5 formed by the confuser section 6 and the cylindrical section 7. The location of the nozzle 1 allows the finely atomized fuel to be fed into the throttle zone as a hollow flame. Below it, on the wall of the cylindrical section 5 of the mixing chamber, ordered recesses 8 are made having a half-oval shape in plan.

 In FIG. 2a shows a scan of the inner surface of the cylindrical section 7 of the mixing chamber, on which the location and shape of the recesses 8 are more detailed. The latter are arranged in several rows in a checkerboard pattern. The largest depression is h, and the longitudinal dimension of the depression (semi-major axis of the oval) is d. In this case, the minor axis was semi-first placed upstream and oriented perpendicular to the direction of flow. The relative location of the recess is uniquely characterized by the distance b between two adjacent recesses and the size a between adjacent rows of recesses. The values of h, d, b, a are determined by the diameter D of the cylindrical section of the mixing chamber and the flow rate of the air-fuel mixture in this section.

 Other arrangements for recesses are possible, for example, as shown in FIG. 2b. In this case, the recesses are located along a helix inclined to the horizontal at an angle β. The distance between adjacent recesses on the same helix is l, and the distance between adjacent helical lines is k. The specific values of the parameters β, l, k are also determined by the value of D and the flow rate of the air-fuel mixture in this section.

 The proposed device operates as follows. The air stream after the air purifier (not shown in Fig. 1) enters the mixing chamber of the device, where it is mixed with the fuel sprayed by the nozzle 1 above the throttle 4. In this case, part of the fuel enters the wall of the mixing chamber and moves along it in the form of a film under the action the flow of the air-fuel mixture and gravitational forces to the output section of the mixing chamber. When passing through a section with recesses, the near-wall flow of the air-fuel mixture is additionally turbulized, as experimentally established by the authors of this application (Fig. 3). This is due to the fact that during the flow around the recesses, the wall layer is carried out into the main stream together with the fuel particles, where the latter are mixed with air, increasing the homogeneity of the air-fuel mixture. This, in turn, improves fuel economy and reduces engine exhaust emissions.

 The advantages of the proposed solution are simplicity and a slight increase in the resistance of the mixing chamber. It can be used not only in central gasoline injection systems, but also in traditional carburetor systems.

 The above justifications of the authors of the application are confirmed by the results of motor tests of the proposed device. In FIG. 4 shows the speed characteristics of the MeM3-245 engine with a central gasoline injection system. In one case, the wall of the mixing chamber was smooth, in the second it had the described semi-oval recesses. The experimental results show that the application of the proposed technical solution allows to reduce specific fuel consumption by 5 ... 10% in almost the entire range of engine operation.

 The proposed solution is simple and efficient. It allows to improve the fuel efficiency of the engine and reduce the toxicity of its exhaust gases by increasing the homogeneity of the air-fuel mixture.

 According to preliminary estimates, this can provide an economic effect of about 15,000 rubles. for one car per year.

Claims (1)

 Mixture-forming device for a gasoline internal combustion engine, comprising a housing with a throttle valve, a fuel injection unit, a mixing chamber with wall turbulators of the air-fuel mixture, characterized in that the wall turbulators are made in the form of wedge-shaped recesses having a half-shaped plan, arranged orderly on the surface of the mixing wall chamber, and the minor axis semi-placed first upstream and oriented perpendicular to the direction of flow.

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