CS207701B2 - Device for supplying the fuel in the combustion engine - Google Patents

Abstract

1428475 Spray carburetters DRESSER INVESTMENTS NV 22 March 1973 [6 April 1972] 13982/73 Heading F1B A fuel/air mixing and carburetting device has opposed wall members 65, 66, Fig. 3 defining a Venturi with at least one wall member being laterally adjustable to vary the Venturi flow area without varying the angular relationship between the Venturi defining surfaces, the Venturi having a diffuser 90 downstream of a sonic throat 88 so as to maintain sonic velocity at the throat down to vacuum levels of 3" Hg and a fuel supply being uniformly introduced upstream of the throat whereby the liquid fuel is finely atomized by the intake air whilst passing through the throat at sonic velocity. A fuel pump 19, Fig. 1, pumps fuel through filter 20 via a pressure regulator 27 to a compensator pressure regulator 28 and thence via a needle valve 29 to variable Venturi device 10 or via a return loop 30. Needle valve 29 is connected to device 10 to regulate fuel in dependence on speed. Regulator 28 controls fuel in dependence on load and is controlled by manifold vacuum via lines 33, 34 modified by auxiliary air bleeds 47, 48 which are respectively dependent on engine temperature and air temperature. A by-pass line 39 supplements the fuel supply during acceleration. Movements of the members 63, 64, Fig. 3 is via arms 69, 70, Fig. 2 from the throttle linkage through cross-shafts 73, 74, cam plates 75, 76 and roller followers 78. The latter carry arms (93), Fig. 5 (not shown), connected to rods (96, 97) which are joined to members 63, 64. The shape of the members 63 may be varied. Fuel is distributed in a uniform pattern through holes 94, Fig. 1.

Description

The present invention relates to an apparatus for supplying fuel to an internal combustion engine.

In most commonly used gasoline engines for automobiles, fuel and air are metered and mixed using a carburetor connected to the engine intake manifold. Although these carburetors manufactured by different manufacturers differ in detail, they are essentially similar and have been considered for many years to be substantially satisfactory for supplying an adequate amount of combustion mixture to the engine.

With the critical throttle pressure resulting from a sufficient suction vacuum level in the pipeline, a sonic flow rate occurs and a conventional carburetor provides scattered particles of relatively satisfactory size for efficient combustion. The critical pressure is essentially 53 percent of atmospheric pressure and is about 48.53 kPa in vacuum units, called the "threshold vacuum". However, under load or acceleration, the suction vacuum in the pipeline sharply drops to a level below the threshold and can now barely be maintained, called the "unsaturated point", so that the above satisfactory particle formation ceases quickly. For a typical carburetor, an unsaturated point occurs at a vacuum of 48.529 kPa to 47.323 kPa. Poor atomisation leads to poor air-fuel mixing and poor distribution of the mixtures to the cylinders, resulting in poor fuel utilization and high pollution at the moment of the largest exhaust. Thus, a conventional carburetor characteristically forms a mixture providing exhaust gases with a low impurity content only at. a relatively high suction vacuum in the pipe of about 40.529 kPa. While at vacuum levels below this value, it provides a mixture producing exhaust fumes with a high content of impurities.

With the advent of environmental regulations, recently introduced by various government regulations, requiring a significant reduction in the pollutant content of exhaust gases in future automobile production, it was soon noted that carburettor inefficiency was per se a significant factor in relation to the overall problem. Therefore, various measures such as exhaust gas re-circulation, use of catalytic converters, etc. have been designed and tested to reduce impurities. However, none of these proposals has been able to successfully approach the low levels of impurities by prescribed standards.

The invention therefore relates to an apparatus for supplying fuel to an internal combustion engine, and is based on a structure having a housing having an inlet and an outlet, which is connected to the engine intake manifold, with a diffuser flow channel between the openings and at least the two having inclined faces forming converging sections with a neck therebetween, wherein at least one of the walls constituting the flow passage is movable perpendicular to the axis of the flow passage, and the fuel supply assembly comprises at least one opening for introducing liquid fuel into the flow passage.

The invention is characterized in that the diverging section of the diffuser has an angle below the neck between one of the inclined surfaces of each wall and the axis of the flow passage in the range of 2.5 ° to 5 °, and that the fuel opening is located in the flow passage above the neck.

According to another embodiment of the invention, each of the walls provided with inclined surfaces is movable perpendicular to the axis of the flow passage and each of these movable walls is symmetrical with respect to the axis of the flow passage.

According to a preferred embodiment of the invention, a follower is disposed on each of the movable walls, and opposed cam walls are each disposed on a rotatable roller disposed on the respective follower, each cam member being rotatably mounted and engageable with the respective follower to cause movement of the wall. and pivotable to the respective follower.

According to a further embodiment of the invention, the rotating rollers are kinematically coupled to rotate in opposite directions to provide opposite movement of the two movable walls.

Preferably, on the remaining portion of the diverging section of the diffuser, the angle between the respective inclined surface of each wall and the axis of the flow channel is between 20 ° and 70 °.

The invention will now be described in more detail with reference to the drawings.

Giant. 1 is a schematic representation of an air-fuel system comprising an apparatus for supplying a fuel mixture to an internal combustion engine.

Giant. 2 is an external view of the device according to the invention in oblique projection partially exploded.

Giant. 3 is a section along line 3--3 of FIG. 2.

Giant. 4 is a section along line 4--4 per os. 2.

Giant. 5 is a cross-sectional view taken substantially along line 5--5 of FIG. 3.

Figures 6 (a) to 6 (e) illustrate various flow channel configurations of a device according to the invention forming Venturi cross sections.

Giant. 1 shows a fuel supply apparatus comprising a mixing and modulation apparatus 10 connected to the intake manifold 12 of an internal combustion engine 14, shown in outline. The mixing and modulation apparatus 10, which will be described in detail below, sucks air from the surrounding space while fuel is supplied from the fuel tank 16 of the automobile.

Turning the ignition switch 18 will cause the fuel pump 19 to convey fuel from tank 16 to filter 20. Depending on consumption, the filtered fuel is either guided further through line 21 or returns via line 22 through a constriction 23 to tank 16. At the outlet of filter 20 is located a regulator 27 generating a controlled pressure flow entering the pressure compensation regulator 28. The purpose of the compensating regulator 28 is to discharge fuel to either the needle valve 29 or to the return loop 30 having a tapered orifice 31 returning excess fuel to the fuel tank 16. The needle valve 29 is operatively connected to the device 10 to substantially control the fuel supply in the speed function, while the fuel consumption in the load function and the like is compensated by the regulator 28. The operation of the regulator 28 is determined by the vacuum in the intake manifold 32 induced by the conduit 33. 38.

The needle valve 29 is controlled by a throttle valve, as is the case in the fuel and air supply apparatus 10 in response to engine operating needs. The bypass line 39 is used to bypass the compensation regulator 28 and feed fuel to the supply line 40 at a point between the needle valve and the device 10. The bypass line 39 includes a pressure accumulator 41 located between a pair of spring loaded check valves 42 and 43. 39 is described in more detail in the dependent application CR 1, but essentially provides this guide with an additional amount of fuel during the acceleration periods.

Optionally, two auxiliary discharges of the air discharge ducts 47 and 48 may be included in the fuel quantity control system, causing changes in the level of vacuum supplied to the chamber 38, depending on the external temperature conditions associated with the operation of the engine. The discharge conduit 47 comprises a thermostatically controlled valve 49 or the like having a header sensor or a suitable dual metal member 51 responsive to the engine temperature. In this arrangement, when starting the cold valve 49, it opens and gradually closes when the engine warms up to the working temperature. Similarly, the discharge conduit 48 includes a thermostatically controlled valve 50 provided with a sensor or bimetallic element 52 responsive to the air temperature at the inlet of the device 10. If the air temperature in the inlet space is below the optimum value, even if the engine is warm or cold, the sensor 52 gives rise to a proportional opening of the valve 50. Increasing the opening of one or both of the air discharge lines 47, 48 results in a reduction of the effective vacuum level in the chamber 38 allowing the amount of fuel flowing to the mixing and modulation device 10 in accordance with with his needs.

The mixing and modulation device 10 will now be described with reference to FIGS. 2 to 5. As shown in the figures, the device 10 comprises an elongated cover 55 provided with an inner central flow passage 56. The flow passage 56 is in vertical communication with the suction. The upper base 58, supported by the crossbar 59, defines an air inlet to the flow passage 56.

The geometrical arrangement of the flow passage 56 is defined by a plurality of adjacent supports supported at right angles to each other and forming enclosures. In one direction transverse to the flow axis, a pair of opposing, spaced apart stationary members 61 and 62 are disposed, between which a pair of spaced apart, relatively movable walls 63 and 64 are perpendicularly disposed. These walls 63 and 64 are of substantially symmetrical construction and are opposedly mounted in the transverse channels 67 and 68 defined between the upper surface of the rectangular base 57 and the lower surface of the crossbar 59. The front surfaces 65 and 66 of the edges of these walls are spaced apart to form a venturi 56 of predetermined geometric configuration extending therebetween. . In order to respond to the needs of the engine, at least one, and preferably both walls 63 and 64 are movable laterally relative to and relative to each other in order to increase and decrease the venturi flow rate.

The movement of the walls 63 and 64 is induced via a throttle coupler operatively coupled to a pair 69 and 70 carrying engagement gear sectors and mounted outside the housing 55. The arms 69 and 70 are pivotally mounted to the pivotally mounted transverse shafts 73 and 74 which move the cam members 75 and 76. Each cam member 75, 76 comprises an arcuate cam cutout 77 in which a rotatable cylinder 78 is received. The central longitudinal recess 79 disposed within between the side walls 80 and 81 is adapted to rotate the rotatable cylinder 78. With each of the cams For example, a pair of spaced longitudinal followers 96 and 97 are laterally connected by the side arms 93, 76, threaded to the rear of the associated walls 63 and 64, and slidably received in the side wall openings 99 and 100. In this way, the rotation of the transverse shafts 73 and 74 causes lateral movement of the walls 63 and 64 by followers 96 and 97 movably mounted in roller bearings 98, one of which is shown. However, the degree of displacement should be regulated fuel supply. This can be achieved by various modifications, including appropriate determination of the gradual desired cam pitch, given by the slots 77.

By means of the above arrangement, air is supplied to the inlet section 82 of the flow channel 56, the inlet opening of which is defined by smoothly rounded outlines 83 of the upper base 58. The inner front side 84 of the partition 59 narrows the inlet section until smoothly just above the converging apex portions 64. These walls further converge to the maximum constriction point, designated throat 88, below which the flow passage 56 extends almost immediately and smoothly into the "primary" diverging section 89 of the diffuser. Further, the downward diverging section 89 of the diffuser sharply passes into the remaining portion 90, which extends more strongly up to the point where it merges with the diverging opening 91 in the base 57. At the same time fuel from tank 16 is continuously conveyed in the required amount through feed line 40 In order to introduce fuel into the air stream, the fuel conduit 40 is provided with a plurality of uniformly spaced fine holes 94 through which the fuel is introduced in a substantially uniform distribution over the surface 84. partitions 59.

The initial design of the geometry for the venturi cross-section 56 can be achieved by trial and error method for optimum performance foxes for any particular engine design. On for? It has been found in the inadequate tests that, although some variation in design can be used, the best performance is achieved when at least some parameters are kept within relatively narrow limits. In order to verify the advantages of the individual designs, various wall configurations 63 and 64 were tested in matching pairs as shown in Figures 6 (a) to 6 (e). It can be seen from the drawings that the inlet section has an angle varying from 0 ° toe, having a rounded radius of 90 ° in case (e), up to a half angle of 45 ° in case (c) and 24 ° in others. Here, the half angle β of the primary diverging section 89 of the diffuser varied from 3 ° to 4 ° 30 ‘within an effective length of 2.86 to 4.78 cm, while the half angle α of the secondary diffuser section 89 varied from 21 ° to 23 °.

The steady-state test results and comparable air to fuel ratios (X / P) are given in Table 1 to determine design criteria and levels of unsaturation for these different geometric configurations.

When interpreting these results, it will be appreciated that these tests were conducted to determine the initial design criteria, and it should also be noted that an automobile equipped with a carburetor similar to the device in this description is unmanageable at these very low air to fuel ratios. Furthermore, in order to improve the understanding of the test results, it should be noted that, according to standard standards, a standard automobile engine in good driving condition generates an average of 900 ppm unburned hydrocarbons (HC), 3.9% carbon monoxide (CO) and 1075 ppm nitrogen oxide (NO _X ). during normal operation at air to fuel ratios of the order of 14 to 15: 1.

AND

Based on the above data, including the observed general appearance of oserosol, which can be observed using a transparent plastic channel and the operational response of the vehicle to which the liner (b) was applied was found to be slightly better in terms of exhaust than the liner (d] and both inserts (b) and (d) were found to be better than the other inserts in the same respect. The lowest unsaturated vacuum was achieved by insert (c), suggesting that the half angle of the primary diffuser should lie within 2.12 ° to 5 ° for a clamped angle of 5 ° to 10 °, with the clamped half angle of the secondary diffuser being 20 ° to 30 °, while the half inlet opening angle should be 20 ° to 70 °. It was also found that the performance between the individual structures was that the resulting engine intake manifold vacuums achieved by the apparatus of of the invention were of the order of 3.4 kPa to 6.8 kPa higher than the values existing in conventional carburetors, which in itself indicates a more efficient combustion of fuel in the engine.

Inserts 63, 64 (fig. 6) Unsaturation (kPa) km./hod. Vacuum (kPa) Table · 1 NOx PPm V / P to 1 CO% CO2 PPm HC ppm (and) 80 55.56 0.16 11.9 20 May 330 18.2 9,132 72 50.01 0.19 10.9 35 120 19.5 empty 47.46 to 62.66 0.10 11.9 92 105 18.2 (b) 80 55.56 0.14 11.8 12 320 18.3 10.13 70.5 48.39 0.16 10.4 28 93 20.4 empty 49.06 0.10 11.9 68 135 12.2 (C) 80 52.8 0.17 11.9 12 408 18.1 9,132 68.5 45.3 0.23 10.6 51 165 20.0 empty 50.1 0.17 12.5 75 150 17.3 (d) 80 55.9 0.18 11.9 12 305 18.2 91,124 69.5 49.06 0,20L 10.8 35 97 19.7 empty 49.7 0.25 11.5 125 113 18.5 (E) B0 56.26 0.18 11.9 16 385 18.2 8,133 72 52.3 0.20 11 35 205 19.3 empty 48.1 0.10 11.5 88 150 18.7

walls 63 to 64 in FIG.

Using the insert (c), changes were made to the total closed diffuser angle to determine the unsaturated vacuum effect, the results of which are shown in Table 2.

Table 2

Total enclosed angle of primary diffuser (Ί Unsaturated vacuum (kPa) 3.5 9.5 4.4 8.8 5.3 8.8 6.0 8.5

Total Clamped Angle Unsaturated Primary Diffuser Vacuum (kPa.) (°)

7.0

7.3

8.3

9.4

9.5

7.5

7.5

7.8

8.5

8.8

On this basis, the lowest unsaturation occurs at the overall grip of the primary diffuser angle between 6.5 ° and 9 °. .

By using the insert (d) with increasing vacuum, the additional data given in Tables 3 and 4 was obtained.

Table 3

Tested unit

Two-chamber carburetor

Speed km / h80

Vacuum (kPa) 47.5

CO ( ¹⁰ / o) 0.13

CO2 (%) 11.5

NO _X (ppm) 335

V / P18.7

HC (ppm) δ

8080

37,3 47,538,9

0.17 0.120.18

10.7 12.110.6

150 570270

19,9 17,920,0

12 12

Table 4 Tested unit Two-chamber carburetor

Speed km / h 78 75 72 78 76 72 " Vacuum (kPa) 30.1 28.9 23.9 25.1 23.3 20.3 CO (%) 0.13 0.16 0.19 0.17 0.2 0.3 CO2 (-%) 11.2 10.9 10.4 11 10.9 10.6 HC (ppm) 8 10 .28 10 12 68 NOx (ppm) 520 290 120 690 600 290 IN P 19.2 19.6 20.3 19.4 19.7 19.9

"On failure

The results shown in Table 4 are particularly well-known since they provide a comparison of the two systems under high load, producing the largest volumes - and the highest NO _x concentration. Again, it is important to take into account that the above data is a standstill comparison since the carburetor-equipped car cannot drive at these V / P ratios. Yet, it is clear that the test unit had better performance resulting from the low NO _X content, while the carburetor car failed at a 19.9 V / P ratio and gave a slower performance than the test unit. Furthermore, the suction line vacuums of the apparatus according to the invention were higher by 3.4 to 5.1 kPa, which indicates an increasing efficient combustion.

A new apparatus for supplying a combustion mixture to an internal combustion engine is described above which effectively reduces the amount of contaminants in the engine exhaust. By creating a venturi cross-sectional flow passage through a device that can be easily changed according to the flow needs of the engine, the device is simple but capable of rapid response, i.e. achieving the results long sought by both industry and various government regulation. However, the operation of the device for alternating or altering the venturi flow surface can be achieved by various well known coupling arrangements which are capable of carefully controlling the lateral displacement of one or both Venturi members relative to each other. Although the displacement between the movable members in the lateral direction changes the flow area of the channel cross-section, their relative angular position in their channel cross-section provides their cross-section geometrically constant.

Despite its simplicity, the apparatus of the invention combines the functions of atomizing, mixing with air, and controlling the air / fuel ratio in a single arrangement to reduce the content of pollutants in the exhaust gas while maintaining or improving controllability and economy. Through the critical geometry of the Venturi cross section, the sonic velocity is maintained, resulting in a relatively low level of unsaturated vacuum. Therefore, a high spray rate is maintained in the pipeline within a wider vacuum range than can be achieved with conventional carburetors. This results in improved mixing, improved distribution to the individual cylinders, and a poorer air-fuel mixture, which contributes to a lower content of pollutants in the exhaust gas at a much more favorable cost than prior art devices serving a similar purpose.

Although the apparatus has been described in connection with the transfer of a combustible mixture to an internal combustion engine with connection to the intake manifold, this does not constitute a limitation, since the device may optionally be used to feed one or more individual cylinders of the engine. Further, likewise, it does not mean limiting or using it in conjunction with an internal combustion engine since it can be used in conjunction with any apparatus requiring a mixture of atomized fuel and air of the type described herein within a wide range of differential pressures.

Since many changes can be made to the above construction, and since many similar, seemingly very different embodiments of the invention can be made without departing from the spirit of the invention, it will be understood that all of the facts contained in the drawings are described. it is to be interpreted in an illustrative and nickel-limiting sense.

Claims (5)

An apparatus for supplying fuel to an internal combustion engine, having a housing having an inlet port and an outlet port which is connected to the engine intake manifold, between the openings there is a flow channel provided with a diffuser and opposed walls, at least two of which have inclined surfaces diverging portions with a throat therebetween, wherein at least one of the walls constituting the flow channel is movable perpendicular to the axis of the flow channel, and the fuel supply assembly comprises at least one opening for introducing liquid fuel into the flow channel, characterized in that the diverging section (89) the diffuser has an angle (Θ) below the throat (88) between one of the inclined surfaces of each wall (64, 6 ₍ 3) and the flow channel axis between 2.5 ° and 5 °, and the fuel bore (94) is located in the flow channel (56) above the neck (88). Device according to claim 1, characterized in that each of the inclined faces (63, 64) is movable perpendicular to the axis of the flow channel, and each of the movable walls (63, 64) is symmetrical to the axis of the flow. channel. Device according to claim 2, characterized in that a follower (96, 97) is disposed on each of the movable walls (63, 64) and the opposed cam members (75, 76) are each disposed on the rotatable cylinder (78), located on a respective follower (96, 97), each cam member (75, 76) being rotatably mounted and engageable with the respective follower (96, 97) to cause movement of the wall (63, 64) and rotatable with the appropriate tracker. Device according to claim 3, characterized in that the rotating rollers (78) are kinematically coupled to rotate in opposite directions to provide opposite displacement of the two movable walls (63, 64). Device according to one of Claims 1 to 4, characterized in that on the remaining part (90) of the diverging section (89) of the diffuser the angle (·) between the respective inclined surface of each wall (63, 64) and the axis of the flow channel is 20 ° to 70 ^p .