Charge Forming Apparatus

Abstract

Charge forming apparatus for metering fuel in which a stream of induction air impinges upon a stream of liquid fuel for changing the shape thereof. Fuel is stripped from the reformed liquid stream for dispersion into the air stream. Single or multiple fuel streams may be employed. The apparatus avoids the use of a float thereby facilitating up draft, side draft, or down draft mounting. One embodiment eliminates the choke plate providing a compact structure having a short air induction passage.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to apparatus for dispersing liquid into an air stream and more particularly to apparatus for dispersing fuel into an air stream for forming a combustible mixture.

2. Description of the Prior Art

The prior art includes aspiration devices such as carburetors and jet receiver apparatus for inducing fuel into an air stream.

Carburetors typically employ a venturi section in an air induction passage which creates a pressure drop across a metering orifice for aspirating fuel into the air stream. An objection to such devices arises from the limitation on air flow through the restriction at the venturi throat. Another objection arises from the difficulty encountered in calibration of the metering orifice. Many prior carburetors employ floats which are sensitive to tilting, and many require an accelerating pump to supplement fuel delivery.

In one form of jet receiver apparatus, fuel deflection is carried out in an auxiliary chamber by means of a fluid amplifier. An objection to such an apparatus arises from the added fluid amplifier system. In other forms of jet receiver apparatus, the fuel stream is diverted from the receiver during timed intervals such as by means of ultrasonic vibration or by an auxiliary air blast. Objections to such prior jet receiver apparatus arise from the auxiliary apparatus required to regulate fuel pressure and/or the duration and repetition rate of jet deflection intervals.

SUMMARY OF THE INVENTION

An object of the present invention is to provide improved charge forming apparatus in which fuel is dispersed from a fuel channel into an air stream in accordance with changes in shape of the fuel stream resulting from impingement of the air stream on the fuel stream;

Another object of the invention is to provide charge forming apparatus which avoids the use of a float thereby facilitating inclined operation;

A further object of the invention is to provide charge forming apparatus in which the proportions of fuel in the mixture are regulated by the configuration of a cap in the fuel channel;

A still further object of the invention is to provide charge forming apparatus having a gap in the fuel channel in which the configuration of the gap is subject to adjustment for regulating the rate of fuel dispersion into an air stream; and

An additional object of the invention is to provide charge forming apparatus having excess fuel available in the air induction passage for responding to increases in fuel requirement;

these and other objects and advantages of the invention will become more evident through consideration of the drawings and following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of one embodiment of charge forming apparatus according to the present invention;

FIG. 2 is a section elevation view taken along the line 2--2 of FIG. 1 showing an arrangement of fuel channels in the air induction passage;

FIG. 3 is a section view taken along the line 3--3 of FIG. 1 showing fuel passages and channels;

FIG. 4 is a fragmentary section view taken along the line 4--4 of FIG. 1, showing an auxiliary air passage;

FIGS. 5, 5a, 6, 6a, 7 and 7a are fragmentary views to enlarged scale showing gap configurations of fuel channels employed in the embodiment of FIGS. 1 through 4;

FIGS. 5b, 6b, and 7b are graphical representations of flow characteristics typical of the fuel channel gap configurations shown in FIGS. 5, 5a, 6, 6a, 7 and 7a;

FIG. 8 is a graphical representation further illustrating typical fuel delivery characteristics of the embodiment of FIGS. 1 through 4;

FIGS. 9, 9a and 9b are fragmentary views to enlarged scale showing an alternate form of fuel channel and gap configuration;

FIG. 9c is a graphical representation of flow characteristics typical of the alternate form of fuel channel gap configuration shown in FIGS. 9, 9a and 9b;

FIGS. 10, 10a and 10b are fragmentary views to enlarged scale showing an alternate form of fuel channel and gap configuration included in the embodiment of FIGS. 11 and 12;

FIG. 10c is a graphical representation illustrating flow characteristics typical of the fuel channel of FIGS. 10, 10a and 10b;

FIG. 11 is a section elevation view taken along the line 11--11 of FIG. 12 showing another embodiment of the invention employing a fuel channel as shown in FIGS. 10, 10a and 10b;

FIG. 12 is an elevation view of the embodimnt shown in FIG. 11;

FIG. 13 is an elevation view of another embodiment of the invention characterized by a short air induction passage, and a fuel enrichment means as shown in FIG. 17 which permits the elimination of a choke plate;

FIG. 14 is a section view taken along the line 14--14 of FIG. 13 showing fuel passages and channels;

FIG. 15 is a section view taken along the line 15--15 of FIG. 13 showing the fuel enrichment means in greater detail;

FIG. 16 is a semi-schematic section elevation view taken along the line 16--16 of FIG. 13; and

FIG. 17 is an enlarged section view of the fuel enrichment means taken along the line 17--17 of FIG. 15.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in more detail to the drawings and more particularly to FIGS. 1 through 4 thereof, the reference character 20 indicates charge forming apparatus according to the present invention. A body 21 includes an air induction passage extending therethrough defined by the inlet or upstream end portion 22, the mid portion 23 and the outlet or downstream end portion 24. If desired, the air inlet passage may be formed with a constant diameter throughout its length, however, as shown in the drawings the diameters of the three passage portions differ, having been chosen to provide substantially equal flow areas in view of the areas occupied by the fuel channels and the choke and throttle plates and shafts.

A choke plate 26 and choke shaft 27 are mounted in the inlet or upstream end portion 22 of the air induction passage. The shaft is rotatably mounted in body 21 and secured to lever 28 by means of which choke plate 26 can be turned to obstruct the air induction passage.

A throttle plate 36 and throttle shaft 37 are mounted in the outlet or downstream portion 24 of the air induction passage. Shaft 37 is rotatably mounted in body 21 and secured to lever 38 for turning the throttle plate to regulate the rate of flow of air through the air induction passage. The portion of body 21 adjacent the inlet or upstream end 22 of the air induction passage is provided with a boss portion 29 for receiving an air cleaner or filter device not shown in the drawings. The opposite portion of body 21 adjacent outlet end 24 of the air induction passage is provided with mounting flanges 31, 31 for connection to the inlet manifold of an internal combustion engine not shown in the drawings. An auxiliary air passage 32, 33, 34 extends in flow parallel with respect to mid portion 23 of the air induction passage. If desired, the body 21 can be provided with a fitting 39 which is arranged to provide a manifold vacuum signal for connection to components used in clean air systems.

Body 21 is provided with a system of internal fuel passages including the fuel inlet 41, inlet passages 42, 43, outlet passages 44, 46 and outlet port 47 interconnected by fuel channels 48, 49 and 51. The fuel channels are provided with surface interruptions defining gap portions 52, 53, 54 facing upstream toward the inlet end 22 of the air induction passage. As will be described more fully hereinafter, the gap portions of fuel channels 48, 49, and 51 are provided with different configurations for responding to idle, mid range and wide open throttle operation.

Idle fuel channel 51 includes nozzle 56 and receiver 57 mounted to define the gap zone 54 off center of air passage 23. Nozzle 56 is secured to a fitting 62 which intersects inlet fuel passage 43 between a pair of spaced seals 63, 63. Fitting 62 includes an aperture 64 and groove 66 for conducting fuel from passage 43 to nozzle 56. Fitting 62 is secured in a bore 67 in body 21 by means of a retainer ring 68 and set screw 69, the retainer ring securing the fitting against displacement from passage 43 and the set screw securing the fitting and nozzle 56 against rotation with respect to the upstream end 22 of the air induction passage.

Receiver 57 is secured to a second fitting 71 which includes an aperture 72 and groove 73 for conducting fuel from the receiver to outlet passage 46. A seal 74 is arranged to prevent leakage along the bore 76 in body 21. FItting 71 includes a threaded portion 77 and a slot 78 by means of which receiver 57 can be moved toward and from nozzle 56 for adjusting the length of the gap zone 54. A lock nut 79 is provided for securing receiver 57 against displacement from its adjusted position.

As shown more clearly in FIGS. 5 and 5a, nozzle portion 56 and receiver portion 57 are formed of hollow tubing and arranged in flow alignment with each other. Nozzle portion 56 is beveled on its upstream side and spaced from receiver 57 to provide the interrupted zone or gap portion 54. The configuration of the inner surface 58 and the oval ring surface formed by beveled wall portion 59 provide a fuel stream modulating surface by which a jet or stream of fuel in nozzle 56 is flattened and widened in the gap or interrupted zone 54 by impingement thereon of the air stream. The end surface 61 of receiver 57 provides stripping surface for deflecting fuel from the margins of the stream and dispersing the stripped portion of fuel into the air stream. The angularity and shape of the beveled surface 59 facing the upstream end 22 of the air passage, the length of gap portion 54 and the inner diameter of receiver 57 are selected to regulate the amount of fuel dispersed into the air stream. While the angle of the beveled surface 59 and the inner diameter of the receiver are fixed values, the nozzle may be slightly rotated with respect to the air passage and the receiver may be moved toward and from the nozzle to provide adjustment of the gap configuration for regulating the fuel delivery characteristics of the channel.

Mid range fuel channel 49 is mounted in body 21 in a manner similar to the mounting of idle channel 51. Nozzle portion 81 of channel 49 is secured in a fitting 83 which includes an aperture 84 and groove 86 disposed in fuel inlet passage 42 permitting flow of fuel from the inlet passage through the fuel channel. Seals 87, 87 are arranged on opposite sides of passage 42 to prevent leakage between the fitting and the wall of bore 88. Fitting 83 is secured in bore 88 by retainer ring 89 and set screw 91.

Receiver portion 82 of fuel channel 49 is secured to a fitting 92 which includes an aperture 93 and groove 94 permitting fuel flow from receiver 82 to outlet passage 44. Fitting 92 includes a threaded portion 96 for adjustment of receiver 82 with respect to nozzle 81 permitting regulation of the size of the gap portion 53. A lock nut 97 provides means for securing receiver 82 against displacement from its adjusted position.

As shown in FIGS. 6 and 6a, the end of nozzle member 81 is telescopically received in receiver member 82 such that the gap portion 53 occurs in the upstream surface of the channel but not in the downstream surface. The beveled surface 117 and inner surface 118 of nozzle 81 provide fuel stream modulating surface by means of which the shape of a stream of fuel in nozzle 81 is changed by impingement thereon of a stream of air in the air induction passage. Impingement of air on fuel in the gap zone 53 causes the fuel stream to become flatter and wider such that the lateral margins of the fuel stream extend outwardly of or strike the stripping surface formed by end wall 119 of receiver 82. Thus portions of the fuel in the fuel stream are dispersed into the air stream.

High range fuel channel 48 includes a nozzle member 98 and receiver member 99 having a gap portion 52. Nozzle 98 is secured to fitting 101 which includes aperture 102 and groove 103 intercepting fuel passage 42 permitting flow of fuel from the inlet passage to the nozzle. Fitting 101 is received in bore 104 of body 21 and secured therein by retainer ring 106 and set screw 107. Seals 108, 108 are employed to prevent leakage along the surface of bore 104. Receiver member 99 is secured to fitting 109 which includes aperture 111 and groove 112 permitting fuel flow from the receiver to outlet passage 44. Fitting 109 includes a threaded portion 113 by means of which the receiver can be moved longitudinally in bore 114 for adjusting the position of receiver 99 with respect to nozzle 98 which in turn results in adjustment of the length of gap portion 52. A lock nut 116 is provided for securing fitting 109 and receiver 99 against displacement from the adjusted position. As shown more clearly in FIGS. 7 and 7a, the end of nozzle 98 has a beveled surface 121 which together with inner surface 122 provide modulating surface in gap zone 52 permitting a change of shape of a stream of fuel in the channel. The end 123 of receiver 99 provides stripping surface for deflecting fuel from the channel into the air induction passage.

Fuel channels 48, 49 and 51 are shown to enlarged scale in FIGS. 5, 5a, 6, 6a, 7 and 7a wherein differences in the gap configuration are illustrated in more detail. Fuel dispersion characteristics typical of channels 48, 49 and 51 are illustrated graphically in FIGS. 5b, 6b and 7b.

The idle fuel channel 51 as shown in FIGS. 5 and 5a is constructed to have a relatively small flow area in the nozzle portion 56 sufficient for idle fuel and light load requirements of an engine with which the apparatus is to be used. The nozzle 56 and receiver 57 are spaced apart at the upstream and downstream walls providing a gap 54. The gap 54 permits a stream of fuel in the nozzle to become flatter and wider as a result of the impingement thereon of air flowing in the air induction passage. An increase in gap length increases sensitivity to low air flow rates up to a point at which substantially the entire stream of fuel is deflected from the receiver.

The line 124 of FIG. 5b illustrates dispersion characteristics typical of idle channel 51. An example of channel 51 was constructed in which the internal diameter of both the nozzle and receiver were 0.032 inches, the angle of surface 59 was thirty degrees with respect to the downstream side of the nozzle, and the gap length was approximately 0.100 inches. A fuel channel constructed as above was tested on flow bench calibration equipment and was found to be capable of flowing approximately 127 cubic centimeters of fuel per minute. At no air flow, the jet or stream of fuel issuing from the nozzle portion expanded in the gap zone and approximately 20 cubic centimeters of fluid per minute was stripped from the stream and deflected into the air induction passage by the stripping surface 61 of receiver 57. As the air flow rate in the air induction passage was increased, the fluid stream became flatter and wider in the gap zone such that increasing amounts of fluid were stripped from the stream and deflected into the air passage until an air flow rate of approximately 80 cubic feet per minute was reached at which point the entire fluid stream of 127 cubic centimeters per minute was deflected below receiver 57 into the air induction passage. In the example channel, the inner diameter of the receiver and the gap length were selected to provide a fluid dispersion rate for supplying the idle fuel requirements and a portion of the light load fuel requirement of a six cylinder internal combustion engine. In general, a decrease in the inner diameter of the receiver or an increase in the gap length results in an increase in initial fuel dispersion. Conversely, a larger receiver inner diameter or a shorter gap length tends to decrease initial fuel dispersion.

The line 126 of FIG. 6b illustrates the flow characteristics of an example embodiment of intermediate channel 49. In the example embodiment, the inner diameter of the nozzle was 0.052 inches, the angle of bevel surface 117 was fifteen degrees with respect to the downstream surface of the nozzle, and the gap length 53 was 0.150 inches. When tested on flow bench calibration equipment, the fuel channel was capable of flowing 440 cubic centimeters of fluid per minute. As indicated by the line 126 the amount of fluid dispersed from the channel increased with increasing air flow in the air induction passage. It was substantially linear with air flow from appproximately 55 cubic feet per minute of air to approximately 165 cubic feet per minute of air. In general, an increase in the length of gap portion 53 tends to increase the slope of the linear portion of characteristic line 126.

The line 127 of FIG. 7b illustrates flow characteristics of an example embodiment of high range fuel channel 48. In the example embodiment, the inner diameter of nozzle 98 was 0.052 inches, the angle of bevel surface 121 was 45.degree. with respect to the downstream surface of the nozzle, and the length of gap zone 52 was 0.060 inches. The fuel channel was capable of flowing 440 cubic centimeters of fluid per minute. As indicated by the line 127, the amount of fuel dispersed from the channel increased with increases in the flow rate of air in the air induction passage, the rate of increase being more pronounced at high air flows. In general, an increase in the length of gap 52 tends to result in increased rate of fuel delivery at higher air flow rates.

FIG. 8 illustrates an air fuel ratio obtainable by use of the above described example embodiments of fuel channels 48, 49 and 51. The line 128 is related to the line 124 of FIG. 5b and indicates the rate of fuel delivery from idle channel 51. The line 129 is related to line 126 of FIG. 6b and indicates the rate of fuel delivery from both idle channel 51 and intermediate channel 49. The line 131 is related to line 127 of FIG. 7b and indicates the total rate of fuel delivery of the three channels 48, 49 and 51. It is to be noted that the particular gap configuration employed in the examples provides idle fuel requirements at low air flow rates, and then provides a substantially constant air fuel ratio at higher air flow rates as indicated by the linearity of line 131.

FIGS. 9, 9a and 9b are enlarged fragmentary views of an alternate form of fuel channel 132 including a nozzle member 133 and a receiver member 134. Nozzle member 133 and receiver 134 are adapted for connection to fuel inlet and outlet passages. Nozzle member 133 includes a slot 136 in the upstream wall and a slot 137 in the downstream wall. In this embodiment of fuel channel, air flowing in an air induction passage impinges on a stream of fuel in nozzle member 133 by means of the upstream slot 136. Impingement of the air stream on the fuel stream forces fuel into the downstream slot 137 where portions of the fuel strike stripping surface 138 defined by the end of slot 137 or stripping surface 139 defined by the end of receiver member 134. Referring to FIG. 9c, the line 141 illustrates the fuel dispersion characteristic of the fuel channel 132 when the receiver 134 is in the full line position shown in FIGS. 9 and 9a. When receiver 134 is adjusted to the dash line position indicated as 142, the fuel dispersion characteristics is as illustrated by line 143. In a similar manner, adjustment of receiver 134 to the dash line position 144 provides a fuel dispersion characteristic represented by line 146, and adjustment to the position indicated 147 results in a fuel dispersion characteristic as represented by line 148. It is to be noted that channel 132 disperses increased amounts of fuel at higher air flow rates similar to high range channel 48. The channel 132 provides an advantage over the channel 48 in that the end of nozzle 133 is telescopically received in receiver 134 which provides and maintains flow alinement in the channel over a wide range of adjusted positions. FIGS. 10, 10a and 10b are enlarged fragmentary views illustrating the gap configuration of fuel channel 151 employed in the embodiment of charge forming apparatus shown in FIGS. 11 and 12. Nozzle member 152 is connected to an inlet fuel passage and has an end portion telescopically received in receiver 153 which is connected to a fuel outlet passage. A slot is formed in the upstream surface of nozzle 152 defining a pair of side wall edge portions 154, 156 and an end wall edge portion 157.

A stream of fuel in nozzle 152 undergoes a change of shape as a result of the impingement of air thereon becoming wider in the gap zone 159. The reformed stream of fuel extends laterally over the sidewall edge portions 154, 156 such that portions of the stream strike stripping surface 157 formed by the end of the slot or the stripping surface 158 formed by the end of receiver 153. The lateral margins of the reformed fuel stream are dispersed into the air stream.

Referring to FIG. 10c, the line 161 graphically illustrates typical fuel dispersion characteristics of channel 151 when the receiver 153 is in the full line position providing a maximum length of gap 159. Line 162 represents the fuel dispersion characteristics when the gap length has been decreased by movement of the receiver to the dash line position indicated as 163. Line 164 represents fuel dispersion characteristics of channel 151 when the gap length has been decreased approximately 50 percent as indicated by the dash line position 166 of receiver 153. Similarly line 167 represents the fuel delivery characteristics of channel 151 when approximately three quarters of the gap length is obstructed as indicated by the dash line position 168 for receiver 153.

The alternate embodiment of charge forming apparatus shown in FIGS. 11 and 12 is designated by the reference character 171 and includes a body 172 similar to the body 21 of embodiment 20. Embodiment 171 employs a single fuel channel and an idle orifice. Body 172 includes an air induction passage extending therethrough having an inlet or upstream portion 173, a mid portion 174 and an outlet or downstream portion 176. The air induction passage may have a constant diameter if desired, however, as shown in the drawings the portions of the passage have different diameters selected to provide substantially equal flow areas in view of the intrusion into the induction channel of the choke, throttle, and fuel channel. The upstream end of body 172 is provided with a boss 177 for mounting an air cleaner, while the downstream end of body 172 is provided with flange portions 178, 178 for securing the apparatus to the induction manifold of an internal combustion engine. A choke plate 179 and choke shaft 181 are mounted in upstream portion 173 of the air induction passage in a conventional manner. Throttle plate 182 and throttle shaft 183 are mounted in downstream portion 176 of the air induction passage in a conventional manner. An auxiliary air passage 184 has an outlet port 187 in downstream portion 176 such that it by-passes mid portion 174 of the air induction passage in which fuel channel 151 is located.

Nozzle 152 of fuel channel 151 is secured to a fitting 189 which includes an aperture 191 and groove 192 permitting the passage of fuel from an inlet passage to the nozzle. Fitting 189 is secured in a bore 193 in body 172 similar to the manner in which fittings 62, 83 and 101 are securd in body 21. Seals 194, 194 surround fitting 189 on either side of groove 192 to prevent leakage between the surface of the fitting and the wall of bore 193. A retainer ring 196 and set screw 197 secure the fitting and nozzle against rotation and displacement with respect to the body.

Receiver 153 extends telescopically over nozzle 152, and as shown in FIG. 11 is in a position similar to position 163 of FIG. 10 providing a gap configuration having fuel delivery characteristics similar to line 162 of FIG. 10c. Receiver 153 is secured to a fitting 198 which includes an aperture 199 and groove 201 permitting flow of fuel from the receiver to outlet passage 202. Fitting 198 is received in bore 203 in body 172 having a seal 204 to prevent leakage between the wall of the bore and the surface of the fitting. An end portion of fitting 198 is provided with a slot 206 and a threaded portion 207 by means of which the receiver can be adjusted with respect to the nozzle to provide the desired length of gap 159. A lock nut 208 on threaded portion 207 provides means for securing fitting 198 and receiver 153 against displacement from its adjusted position.

The downstream portion 176 of the air induction passage includes an idle orifice 209 connected with a fuel passage 211 which is connected to fuel outlet port 212. An idle adjusting screw 213 is adjustable toward and from passage 211 by means of external slotted portion 214 to provide a variable restriction for regulating the fuel delivery capacity of idle orifice 209. While the idle orifice 209 is not essential to the operation of the embodiment 171, it is beneficial for providing idle enrichment, particularly when its location is below the closed position of the throttle plate indicated by dash line 216 in FIG. 11. The idle orifice is exposed to manifold vacuum when the throttle is closed, which results in drawing fuel from the passage 211 even though there is minimal air flow in the air induction passage.

The embodiment of FIGS. 1 through 4 is provided with a choke plate 26 in the inlet or upstream portion 22 of the air induction passage and the embodiment of FIGS. 11 and 12 includes a similar choke plate 179 is the upstream portion 173 of the air induction passage. Each of the choke plates is mounted to permit rotation in the air induction passage to form a variable restriction therein. The pressure drop across the choke plate results in a lower ambient pressure surrounding the fuel channel or channels in the intermediate portion of the air induction passage. When the ambient pressure surrounding the gap zone of a fuel channel is lowered, the stream of fuel tends to expand more fully in the gap zone permitting the dispersion of more fuel from the channel thus providing a richer mixture. The use of choke plates in combination with fuel channels is therefore beneficial during engine starting and warm-up.

Referring now to FIGS. 13 through 17, an alternative embodiment of charge forming apparatus is shown and described, characterized in that it is more compact by reason of having a shorter air induction passage. The shorter air induction passage is made possible by elimination of the choke plate. Cold enrichment of the mixture is provided by means of an enrichment channel.

The charge forming apparatus 220 includes a body 221 having an air induction passage extending therethrough defined by an upstream portion 222 and a downstream portion 223 which may be of the same or different diameters depending upon whether it is desired to compensate for differences in flow area resulting from the throttle plate 224 and throttle shaft 226 extending across the passage.

One end of body 221 includes a boss portion 227 surrounding the upstream end 222 of the air induction passage for mounting an air cleaner thereon. The opposite end of body 221 includes flanges 228, 228 providing means for mounting the charge forming apparatus on an inlet manifold of an internal combustion engine.

An auxiliary air passage is defined by inlet port 229, passage 231, port 232, passage 233 and outlet port 234. During the wide open throttle operation, the auxiliary air passage is ineffective inasmuch as the ambient pressures at inlet port 229 and outlet port 234 are substantially equal. The auxiliary air passage is also ineffective at closed throttle because the edge 236 of throttle plate 224 is slightly downstream of outlet port 234 in the closed position such that the inlet and outlet ports are exposed to substantially the same pressure. As throttle plate 224 is turned from closed toward wide open position, the edge 236 moves upstream of outlet port 234. At part throttle, the pressure drop across the throttle plate results in a somewhat lower pressure at the outlet port 234 causing a portion of the air requirements to bypass the fuel channels. Since a portion of the air requirement does not act upon the fuel channels, a leaner mixture is provided for part throttle operation.

Body 221 has a system of fuel passages including fuel inlet port 237, fuel inlet passages 238, 239, 241, fuel outlet passages 242, 243, 244, fuel outlet port 246, fuel channels 247, 248, 249, and enrichment channel 251. In the illustrated embodiment, three fuel channels are employed, however, the number, type and configuration of fuel channels to be used may be varied to provide a desired fuel delivery characteristic as described in connection with FIGS. 5 through 10c.

Nozzle fittings 252, 253 provide for flow of fuel from passage 238 to fuel channels 247, and 248 and are mounted in body 221 in a manner similar to the mounting of fittings 83 and 101 of FIG. 3. Nozzle fitting 254 is mounted in body 221 in a manner similar to the mounting of fitting 62 and provides for flow of fuel from passage 238 and 239 to fuel channel 249.

Receiver fittings 256, 257 and 258 are adjustably mounted in body 221 in a manner similar to the mounting of fittings 71, 92 and 109 and provide for flow of fuel from fuel channels 247, 248 and 249 to fuel outlet passages and outlet port 246.

The arrangement of the fuel channels and passages is similar to the arrangement described in connection with the embodiment of FIGS. 1 through 4 and it is believed that a more detailed description is not required.

Referring now to FIGS. 15, 16, and 17, the enrichment channel 251 will be described in more detail. Enrichment channel 251 extends across the downstream portion 223 of the air induction passage downstream of the closed position of throttle plate 224. An inner tubular nozzle member 261 is secured to a fitting 262 which is nonrotatably secured in bore 263 of body 221. Fitting 262 includes an aperture 264 and groove 266 which permit flow of fuel from passages 238 and 241 to the tubular nozzle member 261. Seals 267 and 268 are located on opposite sides of groove 266 to prevent leakage between fitting 262 and the wall of bore 263. The upstream wall of nozzle member 261 is interrupted for a substantial portion of its length defining side walls 271, 272 to provide an elongated gap 269.

A rotatable receiver sleeve 273 extends across air induction passage 223 surrounding nozzle member 261 being received in the apertures 274, 276. Receiver sleeve 273 has a portion of the wall interrupted to provide an elongated gap portion substantially coextensive with the gap 269. Receiver sleeve 273 is secured to fitting 277 which is rotatably mounted in bore 278 of body 221. An aperture 279 and groove 281 permits flow of fuel from receiver 273 to fuel outlet passage 244. A seal 282 extends around fitting 277 to prevent leakage along the wall of bore 278. The seal and fitting are secured against longitudinal displacement from bore 278 by a retainer plate 283. An end portion 284 of fitting 277 extends externally of body 221 and is secured to a lever 286 by means of which the fitting and sleeve can be rotated.

Enrichment channel 251 is employed instead of a choke where an enriched mixture is required as for cold starting and warm up of an engine. For cold starting and warm up, the throttle plate 224 is turned to its closed position where it lies upstream of enrichment channel 251. Receiver sleeve 273 is rotated to the position shown in FIG. 17 wherein the gap in the upstream portion of nozzle 261 is exposed. Under these conditions the gap is exposed to subatmospheric pressures from the engine manifold. A stream of fuel in the gap zone 269 expands more fully in the presence of a subatmospheric ambient pressure resulting in an enriched mixture. As the engine progresses through warm up, the receiver sleeve 273 is rotated around nozzle 261 to progressively cover the gap zone 269. Rotation of sleeve 273 in the closing sense confines a greater portion of the fuel stream in the channel such that the mixture becomes less rich. When sleeve 273 is rotated to a fully closed position (180.degree. from the position of FIG. 17), the fuel stream in nozzle 261 is confined in the channel such that its enrichment function is nullified.

It is to be recognized that the foregoing description relates to exemplary embodiments of the invention which may be adapted and modified as required for providing desired mixture requirements.

Claims

What is claimed is:

1. Charge forming apparatus including a body member having fuel passage means and an air induction passage defined therein, and including an adjustable throttle member arranged for regulating the rate of air flow through said induction passage,

said fuel passage means adapted for circulating a fuel stream through said body including a fuel channel extending across said air induction passage,

said fuel channel including a gap portion facing substantially upstream of said air induction passage permitting impingement of an air stream in said induction passage upon a fuel stream in said fuel channel, the configuration of said gap portion defining modulating surface for regulating the shape of the fuel stream in said channel, said fuel channel including stripping surface arranged and disposed for deflecting fuel from said channel into said induction passage.

2. Charge forming apparatus according to claim 1 in which said fuel channel comprises a hollow member extending across said air induction passage having longitudinally extending slotted portions formed in both the upstream and downstream side thereof, said upstream slotted portion permitting impingement of air flowing in said air induction passage upon a stream of fuel in said channel, and said downstream slotted portion including an endwall edge portion providing stripping surface for deflecting fuel into said air induction passage.

3. Charge forming apparatus according to claim 1 in which said fuel channel comprises a hollow member extending across said air induction passage having a longitudinally extending slotted portion formed on the upstream side thereof defining a pair of laterally spaced wall edge portions and an end wall edge portion, said laterally spaced edge portions permitting an increase in width of a stream of fuel in said channel in response to impingement thereon of air flowing in said air induction passage, and said end wall edge portion providing stripping surface for deflecting fuel into said air induction passage.

4. Charge forming apparatus according to claim 3 including an adjustable sleeve member overlapping said slotted portion of said channel hollow member, said sleeve member being movable for modifying the configuration of said slotted portion exposed in said air induction passage.

5. Charge forming apparatus according to claim 4 in which said sleeve and slotted portions are longitudinally movable relative to each other for modifying the length of the slotted portion exposed in said air induction passage.

6. Charge forming apparatus according to claim 4 in which said sleeve and slotted portions are rotatable relative to each other for modifying the lateral extent of the slotted portion exposed in said air induction passage.

7. Charge forming apparatus according to claim 3 in which said laterally spaced wall edge portions extend at an angle with respect to the upstream side of said hollow member.

8. Charge forming apparatus according to claim 1 in which said fuel channel comprises a nozzle member and a receiver member in flow alignment with each other, said nozzle member permitting impingement of air in said air induction passage upon fuel in said channel, said receiver member including stripping surface arranged for deflecting fuel into said air induction passage.

9. Charge forming apparatus according to claim 8 in which said nozzle member includes a portion extending telescopically within said receiver member.

10. Charge forming apparatus according to claim 9 in which said nozzle and receiver members are mounted for adjustment movement relative to each other permitting modification of the configuration of said gap portion.

11. Charge forming apparatus according to claim 1 in which said fuel channel is disposed in said air induction passage upstream of said throttle member, said body including an auxiliary air bleed passage communicating with said air induction passage between said fuel channel and said throttle member.

12. Charge forming apparatus according to claim 11 including a choke member disposed in said air induction passage upstream of said fuel channel, said auxiliary air bleed passage having an inlet end communicating with said air induction passage between said fuel channel and choke member and an outlet end communicating with said air induction passage between said fuel channel and said throttle member.

13. Charge forming apparatus according to claim 1, said fuel channel being disposed upstream of said throttle member, said apparatus having a selectively operable fuel enrichment device comprising an auxiliary fuel conduit extending across said air induction passage including an elongated slotted portion formed in a wall thereof, and a rotatably mounted cover member partially enveloping said conduit, said cover member having control means extending externally of said body whereby said cover member is capable of rotation for selectively uncovering said slotted portion of said conduit.

14. Charge forming apparatus according to claim 1, said fuel channel having a gap portion configuration selected for providing a portion of a desired fuel requirement, said apparatus including additional fuel channel means having a gap portion configuration selected for providing another portion of said fuel requirement.