Metering and mixing device for fuel in port fuel injection engines

Abstract

907,576. Aerating liquids. REGIE NATIONALE DES USINES RENAULT. Nov. 17, 1959 [Nov. 28, 1958], No. 38965 / 59. Class 14 (1). [Also in Group XXVI] A device for metering and aerating a liquid includes a distributer block 1 having a slide face 5 and having formed therethrough a gas passage 3 opening in the face 5 and a passage 2 for pressurized liquid opening in the face 5 adjacent the gas passage; a slide 6 engaging the slide face, the slide having a chamber 7 which communicates with the gas and liquid passages and in which the liquid can be aerated, gas being projected, during operation, into chamber 7 at least in part by the kinetic energy of the liquid passing into chamber 7, the chamber having a circular cross-section and tapering at least over part of its axial length towards an outlet orifice in the slide; and positioning means for adjustably positioning the slide relatively to the distributer block for varying the quantity of liquid to be delivered to chamber 7. As shown, the positioning means comprises grooves 11, 12 parallel to the face 5 formed on the slide's lower and upper edges, these grooves being engaged by knife-edged blades 13, 14 extending in a plane parallel to the slide-face, blade 13 being responsive to a tension spring 15 exerting a predetermined pressure, and blade 14 being responsive to the pressure of a control lever 20 associated with an adjustment screw 22. The crosssectional area of the liquid orifice 4 is altered by moving the screw 22 up or down. If the pressure in the manifold 28 is less than atmospheric liquid under pressure in passage 2 is forced against the side of chamber 7 and reflected through the nozzle 10, gas at the same time being drawn through passage 3. If the pressure in the manifold is atmospheric (open throttle) only the liquid passing through the nozzle 10 will draw a small quantity of gas from passage 3. The liquid jet orifice 4 may have a circular, triangular, or oblong shape. The chamber 7 may be bulbous shape, oblique frusto-conical shape, or in the shape of a large convergent cone followed by a small divergent one. Specification 866,414 is referred to.

Description

Fig. 4 shows a longitudinal section of another embodiment of this slide, in which the mixing chamber is an oblique truncated cone. Fig. 5 shows a longitudinal section of an embodiment of the slide valve, in which the mixing chamber is connected to a first converging cone. is formed with a diverging part, Fig. 6 shows a section view along line aa, where the fuel nozzle opens onto the sliding surface with a triangular cross-section, Fig. 7 shows a section view along line aa, where the fuel nozzle opens onto the sliding surface with a rectangular cross-section. The arrangements according to Figs. 3, 4 and 5 can be combined with those according to Figs. 2, 6 and 7. In Fig. 1, 1 denotes a metal block that serves to accommodate the fuel supply line 2 and the air supply line 3. The fuel supply line 2 ends with a calibrated opening forming a nozzle 4, which, like the air supply line 3, is in A sliding surface 5 opens onto it. A slide 6 is pressed against this sliding surface 5. This slide contains a mixing chamber 7, which during the The illustrated embodiment has the shape of a right truncated cone, but also, as shown in Fig. 4 or 3, the shape of an oblique cone. It may have the shape of a truncated cone or a non-conical body of revolution. The circle 8 at the large base of the truncated cone, which is best seen in Fig. 2, partially obstructs the fuel nozzle 4. The movement of the slide 6 occurs in the direction of line bb (Fig. 2) along a usable path, which is at most equal to the diameter the nozzle 4. Under these conditions, the air supply opening 9 experiences only a slight change in cross-section, so that the air inlet is not affected in any way. The position of the slide is prevented. Circle 10, i.e., the small base of the truncated cone, forms the mixture outlet opening. The cross-sections of the three openings, namely the opening However, openings 4 for fuel, 9 for air, and 10 for the mixture are not independent of each other, and it should be the The cross-section of opening 10 must always be larger than that of opening 4, even when the slide is in the fully open position, and the The cross-section of opening 9 should always be several times larger than that of opening 10, so that the pressure prevailing in the mixing chamber is very deviates little from the pressure in the air supply line 3, so that a pressure change in the mixing chamber 7 does not affect the flow rate. The flow rate of the fuel through nozzle 4 is not changed and is determined solely by the position of the slide. The slider 6 is provided with a groove 11 and 12 respectively at the bottom and top, against which two cutting edges 13 and 14 are pressed, which are equipped with The sliding surface must enclose an angle Σ. The cutting edge 13 is supported by a leaf spring. 15 pressed down, which on one side are against an axis 16 is supported on one side and on the other side against a screw 17. The leaf spring 16 has a notch 18 so that it cannot slide laterally. The The adjusting screw 17 can be secured in its setting by a locknut 19. The cutting edge 14 is pressed by a lever 20 that triggers the changes in fuel metering and is non-yielding (compared to with 15) and which is pivotable about an axis 21. Its end position is determined by a adjusting screw 22, which is secured by a locknut. 23 is secured. The described mechanism is structurally integrated with the intake manifold 24 of an internal combustion engine, through which the air drawn in by the engine passes. air passes through and in which a pressure prevails that is lower than (or equal to) the outside air pressure, depending on the degree of opening of the Air throttle valve 25. The described nozzle 4 has a circular opening in the case of Fig. 2, but can also have a shape that deviates from the circular. The opening may be formed and, for example, as shown in Figs. 6 and 7, take the shape of a triangle or a more or less elongated shape. have a rectangle. The operating principle of the described device is as follows: By screwing in the screw 22, the slider 6 is moved by means of the lever 20 and the cutting edge 14 against the force of the The spring 15 acting on the cutting edge 13 is displaced downwards. The spring 15 is adjusted beforehand (i.e., factory or workshop-style). Screw 17 has its basic setting, which is not changed during operation. The force transmitted through the cutting edge is determined by the Deflection of spring 15 determined. If this force is denoted by F, the component that presses the slider against the sliding surface has the value 2 ■ F · sin a, choosing, The friction component, which opposes the displacement of the slide, has the value 2 · F ■ sin Δ · tan^. The materials used are chosen such that the value of the coefficient of friction tan φ is as low as possible, while the angle φ, as mentioned, is adjusted accordingly. The lowest possible value is chosen. Under these conditions, the disruptive frictional force is practically negligible, and it is the one used for adjustment. The force required for screw 22 is essentially equal to the force F of spring 15. If &rgr; denotes the absolute pressure prevailing in the intake line 24, H the ambient air pressure, and P the pressure of this Fuel, the following operating conditions can occur: 1. If ΔH is equal to the throttle valve 25 when it is fully open, no intake of fuel takes place. Air in line 3 is replaced by the negative pressure, so that the entire mixing energy must be supplied by the energy (pressure head) of the fuel. Provided that the pressure P is kept at a sufficient value, the fuel jet shown at 26 has a high velocity. and touches the face of the truncated cone with an angle β that is kept sufficiently small so that it passes through the opening 10 with almost no loss is reflected through it. Under these conditions, it is the jet itself that exerts a suction effect on the air in line 3 and at the outlet. The opening 10 produces a first mixture that is sufficient, so that the main airflow 27 ensures good atomization. 2. If λ is lower than H, i.e., if the throttle valve 25 is partially closed, air is also drawn in through the opening 10. whose flow energy interacts with that of the jet 26 to produce the desired atomization directly at the outlet of the opening 10 to evoke. If the value of P is constant, the flow rate is a function of the displacement of the slide, specifically a linear function in which In the case where the opening is rectangular, as shown at 4' in Fig. 7, a quadratic function in the case where the opening is triangular, as shown for 4" in Fig. 6. With a circular opening 4 (Fig. 2), the flow rate changes according to an intermediate law. Naturally, the materials used for the slide and block 1 should be able to withstand the effects of humidity and any other relevant factors. The products contained in the fuel must be sufficiently corrosion-resistant.

Claims

Patent claims:

1. Device for continuous pressure atomization of fuel into the intake manifold of an internal combustion engine, in which the The variable flow cross-section metering and atomizing nozzle does not introduce the fuel directly into the intake manifold, but rather through a a fuel-air mixing chamber supplied with primary air, provided between the nozzle and the intake manifold, characterized in that both the line (3) for the primary air and a metering atomizing nozzle (4) arranged at the end of the fuel line (2) into a sliding surface (5) terminate, which are ground over by a control slide (6) that reduces or increases the fuel discharge cross-section of the nozzle (4). the interior of which has a fuel-primary air mixing chamber (7) which is in the shape of a truncated cone or similar truncated shape tapered body, the large and small bases of which each represent mixing chamber openings, the large base of the mixing chamber (7) being such that facing the sliding surface (5) such that it allows both primary air and metered fuel access to the chamber (7), while the small base serves as the transfer opening (10) of the primary mixture into the intake manifold (24).

2. Device according to claim 1, characterized in that the slide (6) has grooves (11) parallel to the sliding surface (5) at the top and bottom. 12) is provided, against which the cutting edges (13, 14) are pressed, which are inclined to the sliding surface in such a way that the force component, which has the tendency to press the slider against the sliding surface, is always a constant fraction of the force which is due to its counteracts displacement, with one of the cutting edges (13) absorbing the pressure of a tuned spring (15), while the other or The driving cutting edge (14) causes the slide to move and is subject to the pressure of a lever (20), the end position of which is determined by a The adjusting screw (22, 23) is determined.

3. Device according to claims 1 and 2, characterized in that the opening of the fuel nozzle has a circular (4), triangular (4") or has a rectangular (4') cross-section. Printed materials under consideration: German patent specification no. 703 155; French patent specification no. 774 636; British patent specification no. 106 210; US patents no. 2,404,081, 2,706,976. This includes 1 sheet of drawings. © 309 540 / 12B 3.63