US2134021A - Hydrocarbon vapor and air mixing device - Google Patents

Description

Oct. 25, 1938.

Oct. 25, 1938.- v LA, T, BARNES 2,134,021

HYDROCARBON VAPOR AND AIR MIXING DEVICE Filled Marh 25, 1935 2 Sheets-Sheet 2 1.. INVENTOR Patented Oct. 25, 1938 UNiTED STATES HYDnocAaBoNvAPoR AND AIR MIXING DEVICE Llewellyn T. Barnes, Hempstead, N. Y.

Application March 25, 1935, Serial No. 12,920

8 Claims.`

The principal object of the invention is to produce a fuel v,vapor and air mixing device for internal combustion engines whereby the air and liquid fuel particles comprising therfuel mixture are brought into desired intimate contact after issuing from` a carburetor whereby better combustible mixture is obtainedv for consumption in the cylinders of the engine.

Another object is to control the flow of the mixture in such a manner that undesirable vortexes and eddy current are eliminated, thereby improving the quality, maintaining the improved quality of the vapor mixture in varying quantities as desired.

Other objects are to improve fuel economy; to reduce the accumulation of unconsumed deposits from partial combustion; andto generally improve vaporization of the liquid fuel to createa totally combustible mixture,

This invention contemplates Ythe incorporation of a simple, eicient and easily installed Venturi tube of special design in the low pressure zone oi and in the intake manifold located between the carburetor throttle valve and the intakevalves of an internal combustion engine.

A further object of the invention is to provide a Yspecially constructed throttle valve operative in connection with the aforesaid Venturi tube, to further improve mixture stability and toautomatically maintain a substantially constant velocity of the mixture in its passage `throughftheexit zone of said Venturi tube; and to provide means whereby the desired exit velocity of the mixture Ais maintained substantially throughout the entire working and speed range of the engine; and to eliminate condensation of the mixture on and around the throttle valve and in the walls of the intake manifold.

Figure 1 is a vertical sectional View through a portion of a carbureter and intake pipe, with one formof the invention applied,

Fig. 2 is an enlarged vertical sectional view of a portion thereof, with modied intake passage,

Figure 3 is a horizontal section therethrough,

Figure 4 is an enlarged view showing-the .valve and a fragment of the Venturi tube in side elevation,

Figure 5 is a vertical section view of a modication,

Figure 6 is a View similar to Figure 3'of the modiiication,

Figure '7 is a vertical sectional view of the Venturi tube with critical dimensions applied,

and

,Figure 8 is a vertical sectional View of a frag- (c1. 4s-1so) ment of theVenturi tube with throat sections bent to yclosed positions.

Figure 9 is a vertical sectional View of a modiiication, j

Figure 10 is a horizontal view throughy its Venturi tube,

Figure 11 is a diagrammatical View illustrating principles of Figures 2 and 9, and Figure 12 is a horizontal cross section of the valve stem of Figure 9.

In the drawings, reference numeral i designates a-portion of .an internalcombustion engine, I

' an intake port thereof, and 2 a standard type of carbureter, including-among other usual parts, a main discharge nozzle 3, main metering restriction il, valve seat and orifice 5, valve '6, acceleratingpump 1, step up passage 8, idling gas discharge holes 9 and air bleed opening I0, substantially as set forth in- Patent 1,909,389.

The carbureter communicates with the intake port I-fby meansof an intake pipe I2 attached to said intake pipe by bolts I4 passing through flanges I5 of the latter and threading into flanges I6 of the former. Between these ilanges are clamped a pair of gaskets I'I and between the latter is clamped a thin metal gasket I8 to the bore of which is permanently aflixed the base oi a Venturi tube 20. The conical approach 2| of the venturi forms an angle of substantially 60 with its base, and the rounded approach 22 to the exit portion 23 is formed on a radius of substantially .6 of the throat diameter. The length of the exit portion 23 is not less than three fourths of the mean throat diameter. These relative dimensions go to make up the novel venturi for preventing the building up of a flow restricting vortex in the inlet cone by preventing an excessive amount of spinning of the gas vapor at highvelocity, thus. increasing the flow capacity of the tube. An active vortex would retard velocity andupset a constant discharge co-efficient.

z While the walls of lthe Venturi exit portion 23 are normally paralleLprovision is made for bending the walls thereof inwardly or outwardly, this being permitted by V-shaped slots 24 providing intermediate throat sections 23. Bending the exit portion sections 23 inwardly, thereby closing the slots 24, tends to decrease the exit area, and bending the exit sections outwardly opens the slots 24 and decreases the vortex and increases the exit area.

The slots 24 provide openings to permit the gradual expansion of the mixture stream and also provide means to sever the liquid particles to make moreV homogenous the mixture, diffusing the fuel particles in the vapor mixture more readily.` The slots also form individual eddy currents that are helpful to the stream at the discharge side, by flattening out the ever-present vortex which is never entirely eliminated, and which vortex is at a right angle to said eddy currents.

Drill holes 254 in the venturi of the juncture of l the exit sections 23 and the rounded throat or approach portion tend to prevent fracture of the sections during bending thereof, and also assure openings even when the slots 24 are entirely closed, thereby preventing an excessive amount of fuel liquid being pocketed in the well 26.V

The Venturi tube described may be employed alone, as illustrated in Figure 5,:in which case the usual throttle valve 28 is employed, and the feed of the carbureter, the reference character 2 is adjusted by changing-the main metering discharge nozzle'3 to a smaller output and otherwise reducing the liquidV fuelsupply according to the particular type of carbureter; Thus economy in fuel consumption is obtainedV through the use of the particular Venturi choke tube 20 and through readjustment of the carbureter.

Further mixture economy with greater power, may be obtained by elimination of the conventional throttle valve 28, provision of a throttling valve 30 in cooperation with the venturi 20, and extension of the step up passage by means of a tube 8 from the previous low pressure side to the new position of low pressure formed by use of throttling valve 30, together with recalibration of the carbureter as aforesaidv and by also reducing the stroke of the accelerating pump I and size of the valve seat orifice 4.

In eliminating the conventional throttle valve, a lever 3| is substituted therefor and a link 32 extending therefrom through the Venturi tube 20 through a drill hole 33. The link rod 32 is free to slide within the drill hole but is conned from detachment-from the valve 30 by a head 34; The drill holes 33 extend parallel with the valve axis and are formed at theinner ends of. V-shaped slots 35 formed in the conical skirt of the valve 3U, thereby providing bendable valve sections 30 which may be bent inwardly or outwardly to close or open theslots 35 kas in the case of the Venturi tube. Y Opposite side edges of each valve section 3U are similarly beveled as at 35 to produce mixture spinning.

The hub 36 of the valve is centrally bored, the bore expanding Venturi-like at its bottom and upper ends 31, 38 respectively, lugs 39 being disposed at intervals in theVenturi-face 38 Vto engage the bottom face of the adjusting nut. 40 to prevent closing of the Venturi passage between the surface 38 andthe nut 40. A coil spring 4| encircles the nut 40 and the hub of the valve, and is held by its upper end 4| passing through the nut and engaging a flute of the .stem 42- upon which the nut is threaded. The lower end of the spring bears against the valve 3D in the crotch between its conical skirt and its hub. i

The nut 40 is adjustably threaded upon the upper end of a fluted stem 42 which is cruciform in cross section and which is formed on its lower end with radial spider arms 42, having their outer ends extended through and clinched into slots 43 provided for this modification in the base of the venturi 20. The spider arms 42 also have shoulders 44 conforming toand engaged with the coni` cal approach 2| of the venturi to assist in maintaining the guide stemA 42' centralized. The step-up passage extension tube 8 is bent to pass longitudinally up one of the guide stem flutes from the high pressure to the low pressure side of the venturi.

Normally, the floating valve 3|) is held closed upon the Venturi tube 20 by the spring 4|, but suction when the engine is running lifts the valve against the pressure of, the spring to a` height limited by the position of the throttle link stop head 34. When closed, an idling mixture flows through the flutes of stem 42 and through the bore of the valve 30, the flutes preventing spinning of the idling mixture, 'and the spider arms42 likewise preventing spinning of the main vapor charge, thereby eliminating a vortex. When the valve Vis open, sufficient vapor passes through the flutes and valve bore to compensate for the area displaced by the valve mechanism.

The slots in the Venturi tube 20 function the same whether the valve is employed or not, and the slots in the valve may be opened or closed to a greater or less extent by bending the sections 30; thereby varying the slots. The valve itself, being conical, spreads the fuel vapor quickly after it leaves the Venturi tube 20, and maintains al constant velocity and a continued spreading of the mixture over the complete working range of the engine, regardless of, throttle position of the valve. The fuel vapor jets finding their way through the slots 35 issue from the upper'side of thevalve in a spinning condition, due to the beveled edges 35 of the slots. These slots` 35 maintain spinning of the vapor as it issues therefrom even. when almost completely closed.

YWhile the invention has been described and illustrated in connection with an up-draft carbureter, it will be understood that the same conditions exist relatively with a downdraft carbureter.

In the modified form shown in Figure 9, instead of a straight parallel walled intake passage, against which the fuel vapor is deflected by the valve, one having an outward bulge I 2 is employed, the bulge being surrounded by a heating jacket I3 for exhaust, auxiliary heat or other fluid. Interiorly, this bulged wall 'I2' is provided with spiral fins I2" which are notched to provide an operating guide for the valve 3|)a the latterbeing substantially the same structurally and functionally as the valve 30 of the first form. This vvalve has a stem 36a cruciform in cross sectionV and is formed with a longitudinal slot 36 which has a lateral branch slot 36 in which latter a crank pin 3| on a crank 3| operates, the crank being attached to a shaft 3| substituted for the conventional throttle valve shaft.

In assembling, when the heater section. and carbureter sections are moved together, the'pin 3| enters the slot'36 and then the branch'slot 36" and thereafter the shaft 3|X enters the slot 36 and reposes at the end thereof. An operating arm 3|EL is provided for the shaft 3|x and is normally urged downwardly by a tension spring 4|n to normally urge the valve toward closed position. Anyvform of external spring means may be substituted for this purpose. The shoulders I2n prevent the valve lifting to a point where crank pin 3| will leave the branch slot 36".

In this modification, the Venturi tube 20, like the bulged wall I2', is an insert within the heater section of the intake section and is provided with vortex preventing'grooves 2|)b as well as a stepup fuel feeding passage 8l. The ribs and grooves of the cruciform valve stem 36a assist grooves .201? in preventing spinning of. the vapor.V This step-up passage is provided to supply additional liquid fuel under certain conditions such as emergency high loads. Under certain other conditions with certain carbureters, this additional fuel may be forced through the step-up passage by the operator; and in connection with certain other carbureters, the additional fuel is automatically passed through this passage in response to the predetermined demand. The outlet of the step-up passage is in the valve seat of the valve 302,A f

`While the advantages of a properly proportioned Venturi tube are present inV all forms of the invention, an added advantage is present in the bulging of the intake passages or portrayed in the diagram, the object of a properly proportioned bulged intake passage and discharge throat is to maintain a desired constant velocity at all engine speeds. By making the throat discharge passage with a cross-sectional area of X, the valve or spreader with a cross-sectional area of. X/2, and with a cross-sectional area of X/Z between the valve stem and Venturi throat, a cross-sectional area of X/2 must be maintained for the annulus between the valve and the bulged intake passage wall for top engine speed when the valve is fully open.

When the spreader valve is approximately half closed, because of lower engine speed, a velocity substantially equal to the velocity at higher speeds should be maintained and this is accomplished by curving the passage wall inwardly at that point to give cross-sectional area of X/4 between the half-open valve and the passage wall, the cross-sectional area of the annulus between the bulged wall and the tapered Side of the valve being reduced also to X/4. The crosssectional area of the Venturi throat has a constant of X/2.

What is claimed:

l. In a mixing device of the character described, a pipe line leading from a source of vapor supply to the intake of an internal combustion engine, a Venturi tube in said pipe line, a iiuted stem passing axially through the Venturi tube, and a valve adapted for cooperation with the exit portion of said Venturi tube and having a bore through which the stem passes, a nut threaded upon the stem, and a spring having one end bearing against the valve and its other end passing` through the nut into engagement with the flutes of the stem.

2. In a mixing device of the character described having a pipe line leading from a source of vapor supply to the intake of an internal combustion engine, the combination of a Venturi tube member located in the pipe line, said Venturi tube having a conical mouth portion, a rounded throat portion, and a substantial cylindrical discharge portion; a conical valve member having its tip end located within the discharge portion of the Venturi tube and its sides adjacent its base engaged with the end of the discharge portion of the Venturi tube when said valve is in its closed position, and guide means to coniine the movement of said valve in a direction axially of said Venturi tube in its opening and closing movements, one of said members being provided with vortex disturbing slots extending in the general longitudinal direction of the axis of the Venturi tube.

3. In a mixing device of the character described having a pipe line leading from a source of vapor supply to an intake of an internal combustion engine, the combination of a Venturi tube located in the pipe line, said Venturi tube having a coni'- cal mouth portion, a rounded throat portion, and

a substantially cylindrical slotted discharge portion; a conical throttle valve mounted to move .axially of the Venturi tube and When in closed position having its tip end located within the Venturi tube and its sides adjacent its base seated upon theV end of the discharge portion of the Venturi tube, means working through said Venturi tube for operating the valve, and a tube from the source of vapor supply communicating through said valve with the low pressure side of the Venturi tube.

4. In a mixing device of the character described having a pipe line leading from a source of vapor supply to the intake of an internal combustion engine, the combination of a Venturi tube located in the pipe line, said Venturi tube having a conical mouth portion, a rounded throat portion, and a slotted substantially cylindrical dischargeV portion; a conical throttle valve mounted to move axially of the Venturi tube into and out of closing engagement with the end of the discharge portion of said Venturi tube, the tip end of the valve being located within the Venturi tube and the sides of the valve adjacent its base seating upon said discharge end of the Venturi tube when the valve is closed, the Valve having an axial bore, a iiuted valve guide arranged within said bore axially of the Venturi tube, and a tube leading from the source of vapor supply and located in one of the ilutes of the valve guide and in the bore of the valve to discharge vapor into the latter.

5. In a mixing device of the character described having a pipe line leading from a source of vapor supply to the intake of an internal combustion engine, the combination of a Venturi tube member located in the pipe line, said Venturi tube having a conical mouth portion, a rounded throat portion, and a substantial cylindrical discharge portion; a conical valve member having its tip end located within the discharge portion of the Venturi tube and its sides adjacent its base engaged with the end of the discharge portion o1' the Venturi tube when said valve is in its closed position, and guide means to confine the movement of saidvvalve in a direction axially of said Venturi tube in its opening and closing movements, said discharge portion being provided with vortexv disturbing slots extending in the general loigitudinal direction of the axis of the Venturi tu e.

6. In a mixing device of the character described having a pipe line leading from a source of vapor vsupply to the intake of an internal combustion engine, the combination of a Venturi tube member located in the pipe line, said Venturi tube having a conical mouth portion, a rounded throat portion, and a substantial cylindrical discharge portion; a conical valve member having its tip end located within the discharge portion of the Venturi tube and its sides adjacent its base engaged with the end of the discharge portion 0I ply to the intake `of an internalcombustion 'ensaid Venturi tube havingk a converging entrance portion leading to a throat and having a substantially cylindrical discharge lportion beyond the throat portion, said discharge .portion being spaced from said pipe lineandy provided. with longitudinal vortex disturbingY slots through which minorpportions of the vapor'in passing through said slotsis directed substantially'coni-l cally, said slots providing `substantially cylindrically arcuate segments comprising said discharge portion,k whereby the major portion of said vapor is substantially conned inan unswirled column and flowing in a direction coextensive with said discharge portion substantially throughout said pipe line portion. .i Y

8. A mixing device of the character described including in combination a unidirectional portion of a pipe line leading from a source of vapor supply to an intake of a combustion enginesaid portion including an enlargedconcentric annular portion, said annular portion providing a concave annular passage, a Venturi tube in said portion and disposed coaxially and concentrically therein, said Venturi tube having a conical mouth portion, an arcuate throat portion, and a substantially cylindrical discharge portion terminating substantially upstream of Vsaid enlarged annular portion and spaced from said pipe line, a conical throttle valve having its tip end located Within the discharge passage of the Venturi tube, said valve having its sides adjacent its base engageable with the end of theV discharge portion of the Venturi tube when said valve is in its closed position, and guide means to direct the movement of said valve axially of said Venturi tube whereby the vapor passing said Valve is deflected .into said concave passageway during all open positions of said valve.

LLEWELLYN T. BARNES.

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