US3081160A - Carbureter and combined carbureter and regulator - Google Patents

Description

March 12, 1963 R. F. ENSIGN CARBURETER AND COMBINED CARBURETER AND REGULATOR Filed Dec. 15, 1958 4 SheetsSheet l Mad.

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March 12, 1963 R. F. ENSIGN 3,081,160

CARBURETER AND COMBINED CARBURETER AND REGULATOR Filed Dec. 15, 1958 4 Shee tsSheet 5 IN VEN TOR.

March 12, 1963 R. F. ENSIGN 3,081,160

CARBURETER AND COMBINED CARBURETER AND REGULATOR Filed Dec. 15, 1958 4 Sheets-Sheet 4 :96 46? 502 422 a "Q 3C Bay JW E A/s/G INVENTOR.

Unite Stae 3,081,160 CARBURETER AND CGMBINED CARBURETER AND REGULATQR Roy F. Ensign, Fullerton, Califl, assignor, by mesne assignments, to American Bosch Arrna Corporation, a

corporation of New York Filed Dec. 15, 1958, Ser. No. 738,512 1 (Ilaim. (Cl. 48-484) This invention relates to carbureters and carbureterregulator combinations for forming and feeding gaseous fuel and air mixtures to devices using such mixtures, for example internal combustion engines. The carburetors and carburetor-regulator combinations of the invention have been designed with a particular view to being installed on the upper air intakes of down-draft liquid fuel carburetors, where the vertical space between those intakes and the covering hood in an average automobile is restricted. That is one of the objects and advantages of the invention; but, as will appear from the following descriptions, there are other accomplishments and advantages of the invention that are not dependent on that use. Accordingly the invention is not limited to that specific use. The objects and corresponding accomplishments of the invention will be best understood from the following descriptions of structures in the nature of illustrative embodiments of the invention, and their modes of operation. Such illustrative embodiments are shown in the accompanying drawings, where:

FIG. 1 is a central sectional view of one form of combined carburetor and regulator, with certain parts in elevaticn;

FIG. 1a is a fragmentary sect-iton of those certain parts of FIG. 1;

FIG. 2 is a section on line 22 of FIG. 1;

FIG. 3 is a central section of a carburetor of the type shown in FIG. 1; and

FIGS. 4, 5, 6 and 7 are central sections of modified forms of the carburetor of the invention.

Referring first to the form of carbureter shown in FIGS. 1, 2 and 3, a base member 20 is formed with an outlet passage 22 adapted at 24 to be secured to and communicate either with the intake manifold of an englue, or of any other device using the produced combustible mixture, or with the air intake of a liquid fuel carburetor, such for instance as is shown at 26 in FIG. 4-. "FIGS. 1 and 3 show the outlet passage 22 equipped with a throttle 28; but if any of the carburetors here described are mounted on the air intake of a liquid fuel carbureter, the throttle normally associated with the air and mixture passage of that carburetor will, or can, control the output of the carbureters here described.

Member 20 forms the base wall or plate of an air intake chamber 62 whose side wall, preferably circular, is formed by an annular air filter 36, here shown as made up of two spaced screen Walls 32 with a suitable filter filling 34 between them. A cover plate 36, held down by suitable means such as screws 38, forms the top wall of the chamber.

Referring for the moment more particularly to FIG. 3, a gas distribution chamber 40 of fiat circular shape, is formed within top and bottom wall members 42 and 44, held together and held down on spacers 46 by screws 48 which are spaced around members 42, 44 as shown in FIG. 2. As will appear, the section of FIG. 2 applies to the form of FIG. 3 as well as that of FIG. 1, excepting only certain details of difference. Spacers 46 space bottom wall member, and the whole gas distribution chamber 40, above base wall 20. In the form of FIG. 3, the feed of gaseous fuel at suitable pressure to the disassess: Patented Mar. 12, 1953 2 tribution chamber 40 is via a short nipple 50 forming an extension of the initial inlet fitting 52 secured to the under side of 20. The vertical spacing of 44 above 20 may be adjusted by substituting spacers 46 of different lengths; and nipple 50 may have a close sliding fit in opening 54 to facilitate that adjustment.

Bottom wall 44 of the gas distribution chamber 40 has a plurality of gas outlet orifices 56 in circular arrangement concentric with the axis of chamber 40. As shown in FIG. 2, there are, for example twelve of the orifices 56. These orifices discharge directly into the space 60 between the distribution chamber 40 and the base wall 20. The passage formed by that space constitutes the venturi of the carbu-reter, as will appear. In this connection note that the circular array of evenly spaced orifices 56 is outside the maximum circular size of outlet 22, with which the orifice array is in concentric relation. The maximum circular opening of outlet 22 is indicated at 22a, in FIGS. 1, 2 and 3.

Assume a suction (eg, the suction of an internal combustion engine) applied to outlet 22. Air will be drawn in through filter 30 uniformly around its circular extent, and drawn under chamber '40 in circular uniformity radially inwardly to the outlet. In flowing through the passage formed by the spacing 60 the air flow has a velocity dependent on its volumetric flow and the vertical width of that passage. That velocity causes a lowering of pressure by venturi action in the passage 60, and that lowered pressure draws the fuel gas through orifices 56 to mix with the air flow going out through 22. The feed of gas to 40 via 52 will preferably be at about atmospheric pressure, or, under pressure regulator controls Well known in the art, at about the effective pressure in the air intake chamber 62 surrounding gas distribution chamber 40. In FIG. 1, where a pressure regulator is combined with the carbureter, the gas feed pressure is automatically regulated to bear a fixed relation to the effective pressure in the air chamber.

The carbureter shown in FIG. 1 is essentially the same as that shown in FIG. 3, except for the position of the initial gas feed opening to the gas distribution chamber, and the location of the screws 38 that hold cover 3'6 down. Parts that are the same as in FIG. 3 are given the same numerals.

In FIG. 1 the upper wall member 420 of distribution chamber 40 is extended to form the lower half of a regulator chamber enclosure, with a surrounding wall 42b. That chamber 7!), closed at its top by diaphragm 72, is the delivery chamber of the regulator in which the pressure is regulated by the action of the diaphragm on inlet valve 74- through valve lever 76. The upper side of the diaphragm is directly exposed to the existent pressure in air chamber 62, but preferably covered by protective cover '78 having an aperture 81} through which the diaphragm is directly and freely exposed to the pressure in the surrounding chamber 62. Valve 7-4 controls an inlet 82 which is fed with gas under suitable pressure through a nipple 84 leading from inlet fitting 86. Nippic 84 may have close sliding fit at either its upper or lower end to facilitate adjustment in the width of passage space 60 as before explained. Delivery chamber 79 delivers directly to distribution chamber 46 through an opening 54a which may be quite large; in full effect chamber may normally be preferably wide open to chamber 469 if an economizer (see below) is not used.

If the valve-diaphragm system 72, 74 is not biased in either direction, the pressure at which the regulator delivers, and the pressure in chambers 44) and 70, will be the same as the effective air pressure in air intake chamber 62. Preferably, however, the system is slightly biased by spring in valve closing direction so that the valve will close when pressures on opposite faces of the diaphram are equal.

Whether or not the system is biased, the delivery pressure in 70 and 40 always bears a fixed and definite relation to that in air intake chamber 62. Chamber 62 forms the air intake to the carbureter. In the usual arrangement for feeding gaseous fuel from a pressure regulator to the usual carburetor, a balance tube, sometimes quite long, extends from the air intake to the regulator reference chamber at the outer face of the controlling diaphrag-ma chamber like that here shown at 78a under cover 78. On rapid changes of efiective pressure in the air intake, the length of the balance tube slows down the delivery pressure response of the regulator to such pressure change. But here, with the regulator located in the air intake, control diaphragm 72 is directly and immediately exposed to the air intake pressure. Cover 78 may be omitted; but in any case opening 80 is large enough that the diaphragm is directly and freely exposed to the pressure in 62.

Another advantage inherent in the combination of FIG. 1 is the direct and open communication of regulator chamber 70 with distribution chamber 40. In full effect the two chambers are one, except that it may be preferable to feed 40 through a central opening 54a sym metric with relation to the circular array of orifices 56, or at least not opposite any of them.

This wide open communication makes it practicable to control the air-to-fuel ratio solely by the sizing of orifices 56. The same may be said of FIG. 3, providing the feed tube 52 from the pressure regulator is made large enough. Ordinarily however such feed tubes are long, and a mixture controlling adjustment valve is incorporated in them.

The combination arrangement of FIG. 1 also makes it possible to incorporate certain mixture ratio controlling devices in a very simple and direct manner. For example, an economizer 100 is shown in FIG. 1 and in enlarged sectional detail in FIG. la. As there shown a small diaphragm 102 has a diaphragm chamber 104 above it closed by cover 106. Chamber 104 is subjected to engine intake suction from beyond throttle 28 via pasmges 108 and slip nipple 110. The diaphragm carries a valve closure 112 which, on upward diaphragm movement, closes down the port 114 that, like port 5411, leads directly through wall 42a from chamber 70 to distribution chamber 40. The bottom wall 107 of the economizer body is spaced above wall 42a by spacers 109, so that port 114 is in free communication with chamber 70. A spring 116 biases the diaphragm and valve down to keep port 114 open when the manifold depression is low, as it is at wide open throttle and engine operation at full power. At medium ranges of operation, with greater manifold depression, valve 112 is moved upwardly to close port 114 down. With port 114 open, chamber 70 may be wide open to 40. With port 114 closed down the communication of 70 to 40 is correspondingly reduced, to thin the fuel-and-air mixture for economy. The range of economizer action can be adjusted by changing the removable valve seat 115 that carries port 114 to substitute ports of different sizes. Port 54a may likewise be formed in a removable member 55 so that the siZe ratio of ports 54a and 114 may be adjusted. Although port 114 may be large enough, with valve 112 open, to constitute the whole free feed from 70 to 40, preferably the major feed is through 54a. and the relative eiiective size of 114 is comparatively small.

FIG. 4 shows a variant carbureter form in which the gas distribution chamber, located in the air intake chamber 62, is associated with the top cover plate and the gas feed is into the distribution chamber centrally from above.

As shown here the base wall 201 has an upstanding walled delivery passage 221. The base wall 201, filter 30 and cover plate 361 enclose the air intake chamber 62 around 221 and the distribution chamber 401. Cover 361 forms the upper wall 421 of the distribution chamber. Its lower wall 44 is provided with the described circular array of orifices 56. Gas feed is through the central port 541 through wall 421. Spaced below wall 44 by spacers 461 to form the venturi passage 601 is a plate 201a with a discharge neck 221a having a close sliding fit in delivery 221. This fit facilitates adjustment of the width of the venturi passage 601 by changing spacers 461; the parts 201a, spacers 461, and wall 44 all being held to cover 361 by the screws 481.

The carbureter operation here is in substance the same as in FIGS. 1 to 3. Air fiows radially inwardly in circular uniformity from air chamber 62 through the venturi passage 601 to reach the central discharge neck 221a, drawing the gas through orifices -56. Discharge neck 221a has the same concentric relation to the circular array of orifices 56 as described for outlet 22 in FIGS. 1 to 3. The regulator of FIG. 1 can be mounted on the upper wall 421 of the gas distribution chamber here, the same as it is mounted on corresponding upper wall 42a in FIG. 1; with the same direct connection between the regulator delivery chamber and the distribution chamber.

In the form shown in FIG. 5, the venturi passage 602 is formed between the distribution chamber 402 and the cover plate 36. Base 202 carries an upstanding walled outlet 222 and the lower Wall member 442 of the distribution chamber rests on the wall of that outlet. Upper wall 422 has the described circular array of gas discharge apertures 56 concentrically surrounding the central discharge passage 224 that extends through the annular distribution chamber 402. The distribution chamber is spaced below the cover plate by spacers 462. The whole assembly is held together by the bolt 382 that holds cover 36 down on the annular filter 30. The initial gas feed is similar to that in FIG. 3, through a nipple 502 from inlet fitting 52. Adjustment of the width of venturi passage 602 may be made by substituting spacers 462 and either changing the height of outlet wall 222 or by placing an annular spacer under cover 36' on top of filter 30.

Air from air intake chamber 62 flows radially inwardly in even circular distribution through venturi passage 602 and over the gas orifices 56, and thence the mixture flows down throught central outlet passage 224 and discharge 222.

The form of B66 is generally similar to that of FIG. 5, but the venturi passage 605 is here formed between a plate 36-5 and the upper orificed wall of the distribution chamber. In this form the lower base member 205 has a central upstanding walled discharge 225. The distribution chamber 405 is formed around the discharge wall Within and below an annular wall 425 that rests on base 205. The upper part of annular Wall 425 is convexly curved in section, as seen at 425a in the figure, and the circular array of orifices 56 is placed at the top of the convex curve. Plate 365 is adjustably spaced above the orificed wall by spacers 465, and the venturi passage at 605 is formed between that plate and the convex orificed wall. Initial gas feed is from inlet fitting 52, which is here shown fitted with a flow adjustment plug 525. Operation is the same as in FIG. 5.

In all of the forms so far described the air flow through the venturi passage is radial and circularly evenly distributed. That is also true of the form of FIG. 7 which is similar to FIGS. 4 and 6 but not, as shown, including a surrounding air filter and air intake chamber.

In FIG. 7, the annular gas distribution chamber 406 is enclosed in upper and lower annular walls 426 and 446 which form the central air inlet opening 62a into which air may flow directly from atmosphere, or through an inlet fitting such as 62b which may be equipped with a filter. Or, instead of using the air inlet fitting 62b, the carbureter structure of this figure may be enclosed within the surrounding air chamber, as, for instance, in FIG. 5. Lower wall 446 of the distribution chamber rests directly on the walled discharge member 226. described circular array of gas outlet orifices 56 is in lower Wall 44 6 surrounding the central air inlet 62a. A circular venturi forming plate 366 is adjustably spaced below lower Wall 446 by spacers 466, its periphery being spaced inwardly from the wall of 226 to allow an annular discharge passage. Initial gas feed is by fitting such as 52 connected directly to the distribution chamber.

In operation air is drawn down through central air inlet 62a and then flows radially outwardly in even circular distribution through the venturi passage 666 over plate 3566 and under gas orifices 56. The mixture then flows outwardly and down over the periphery of 366 and down through discharge 226.

A characteristic of all of the several forms resides in the radial and circularly distributed air flow through a venturi passage where one passage forming wall has a circular array of gas orifices discharging gas into the radial air flow at a number of distributed points. One of the beneficial results of this arrangement is a marked improvement in even distribution and admixture of the gas to form a final mixture having the same mixture ratio in all its parts.

Another advantage inherent in the designs of the invention is the relatively short axial length of the whole carburetor assembly, the whole assembly being flat rather than long. And the assembly lends itself most readily to being completely enclosed Within an annular air filter. And within the air inlet chamber within the filter a pressure regulator can be mounted in direct feed communication with the gas distribution chamber, and in direct pressure control exposure to the effective air pressure in the air inlet chamber.

I claim:

A combined carbureter and pressure regulator, comprising in combination a substantially flat, circular, walled air inlet chamber enclosed by two substantially circular spaced walls 40 2,939,775

The

and a peripheral air filtering wall, a discharge outlet leading through one of said walls,

wall structure forming a circular gas distribution chamber within the air inlet chamber,

the distribution chamber having a circular wall fixedly spaced from said one wall of the air inlet chamber, in concentric relation to, and extending radially outward beyond, the discharge outlet,

the space between the two spaced walls being open at its outer periphery to the interior of the air inlet chamber and forming a passage through which air may flow radially inwardly to said outlet,

a circular array of spaced gas distribution orifices extending through said circular distribution chamber wall in concentric relation to said discharge outlet and radially outward therefrom,

a gas ressure regulator mounted directly on a wall of the distribution chamber opposite its said orificed wall and located entirely within the air inlet chamber,

said pressure regulator having a delivery chamber in open communication with said distribution chamber,

a pressure regulating diaphragm forming a wall of the delivery chamber opposite the distribution chamber and exposed on its inner face completely and solely to gas pressure in the delivery and distribution chambers,

the outer face of said diaphragm being exposed directly, completely and solely to the air pressure in said air inlet chamber,

a fuel gas inlet to said delivery chamber,

and diaphragm actuated valve means controlling said gas inlet.

References Cited in the tile of this patent UNITED STATES PATENTS 1,292,677 Barrett Jan. 28, 1919 2,754,185 Ensign July 10, 1956 2,871,976 Sebok Feb. 3, 1959 2,927,848 Baverstoek Mar. 8, 1960 Middleton June 7, 1960

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