DE1526685A1 - Method and device for presetting carburetors - Google Patents

Description

_Γ 1525685 -,

PATENT LAWYERS

DIPL.-INQ. FTHIELEKE _ρ , _ _ _{FR | OKE} DR.-INQ. R. DDRINQ DIPL.-PHYS. DR. J. FRICKE

BRAUNSCHWEIG MUNICH

11 289

September 22, 1969

Hollay Carburetor Gompany, 11955 K. Iine Mile Road, Warren, Michigan / USA

Statute of limitations and device for presetting carburetors.

The invention relates to a method and an apparatus for pre-setting the fuel flow in carburettors for internal combustion engines.

In internal combustion engines, it is often desirable to maximum idle fuel flow to a predetermined value to limit. This is particularly necessary for machines that are installed in motor vehicles, which in areas are sold with strict exhaust gas regulations. the The most obvious measure to use specially dimensioned idle setting nozzles does not guarantee compliance with a maximum fuel flow within fixed predetermined Limits, because due to the normal manufacturing tolerances, a carburetor manufactured in this way can very quickly change from its predetermined Tolerance values fall. In the previously common carburetors, therefore, the maximum idle current for each individual carburetor at the end setting must be the last

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Step occurs in the carburetor production, set separately will.

Also, it is often necessary and desirable to have the relationship of the fuel-air mixture, which is supplied to the engine when the throttle valve is partially open, within to keep very tight limits. Since motor vehicles are mostly operated with the throttle valve partially open, by limiting the air-fuel ratio-airflow curve when the throttle valve is partially open, a relatively lean fuel-air mixture is achieved within very narrow limits and thus the undesirable exhaust of unburned Hydrocarbons reduced. At the same time, however, it can Mixture does not become too lean in order not to influence the operation of the machine.

It is the object of the invention to show a method and to create a device with which the maximum fuel flow for idling and engine running with only partial open throttle valve can be preset.

According to the invention, this object is achieved in that initially the throttle valve required for idling Air flow through the carburetor is adjusted, whereupon in the flow direction behind the fuel transfer the 'fuel flow immutably limited to a fixed maximum value is in such a way that the fuel /

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Air ratio only to values below that of the maximum fuel flow certain maximum value can be set.

A carburetor has generally proven to be advantageous for the implementation of this method, in which the fuel transfer is provided with an initially adjustable limiting device that can subsequently be blocked against Vera , to limit the fuel flow through the fuel transfer to a maximum value and in series with an adjusting device that can be adjusted by hand Change in the fuel flow in the area below the limited maximum value are assigned.

The arrangement in which the force « substance enters the intake duct through a fixed opening, see above made that the fuel transfer at least one transfer passage has, which discharges in the flow direction above the fixed opening into the intake channel and from the Fuel transfer is fed, and that the restriction device in the flow direction behind the transfer passage is arranged.

According to the invention, the maximum no-load current is through a second in series with the usual manually adjustable Idle adjustment screw controlled by the adjusting screw »

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said second additional set screw being so arranged is that an adjustment is possible during the final adjustment idea of the carburetor, but this is possible after the adjustment Adjusting screw can be set so that the maximum no-load current preset in this way always occurs later Fuel-air mixture is generated whose value is within the required Exhaust regulations lies.

An inventive Voreinetellvorrichtung for carburetor can can be produced very easily and with cheap means. Above all, it can also be used retrospectively for a wide variety of applications Carburetors can be attached with only minor modifications. It enables a very β without head and simple the carburetor for the finished test.

Of course, the measure according to the invention can also at the metering device of a carburetor for the actual Power setting apply. In this case too, the additional adjustment device is preferably an in Row to the actual power adjustment device arranged second adjusting hood * with which independent of the Droesel flap position a constantly effective fuel supply adjustable iöt. In this way it is very easy to position of a predetermined fuel * »air mixture for operation of the machine with the Droseel flap only partially open possible · This means that a predetermined amount of fuel through the opening into the

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• Main pipe flows regardless of whether the main valve is open or is closed. Even with this preset according to the invention After setting the carburetor, this additional adjusting screw is set so that the once set fuel-air mixture, which is supplied when the throttle valve is only partially open, is always within the desired range and the required exhaust gas regulations are sufficient.

This presetting device for the power setting device of carburetors can also be used in the most varied of carburetor types, for example carburetor types with known vacuum-actuated diaphragms or pistons or power adjustment devices operated by mechanical linkages.

The invention is illustrated in the following on the basis of schematic drawings .gen explained in more detail using exemplary embodiments.

Fig.1 shows the partial view of a carburetor with one according to the invention Metering device}

Mg.2 shows a cross section along line 2-2 of Mg.1;

Figure 3 shows a partial cross-section along line 3-3 after]? ig.1}.

8AD ORIGINAL

Pig. 4 shows a partial cross-section along the line 4-4 Fig. 2}

5 and 6 show partial cross-sections of various embodiments of the section according to Pig. 4}

Pig. 7 shows an enlarged view of the section according to FIG

Fig. 8 shows a partial cross section of a modification of the embodiment according to Fig. 5}

Pig »9 shows a top view of a carburetor with another Embodiment for the idle setting according to the invention;

Pig »IQ shows a partial cross-section along the line 10-10 after Pig »9J

Pig. 11 shows a partial cross section along the line 11-11 Pig.10j

Pig. Figure 12 shows a partial cross-section along line 12-12 after Pig. 11 j

Fig. 13 sseigt a Teilquersehnitt of another embodiment with a © rfindungsgemäßen Kraftatoffzumeßaystem for only partially opened Brosaelfciappe%, ·

Pig »14 shows a» partial section of a variant of the execution. for example according to Pig.13j

m. κ

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Pig. 15 shows part of a modification of one Part of the arrangement according to PIg.14 $

Fig. 16 graphically shows the relationship between the fuel f-air ratio and the air flow in an inventive Fuel metering system for only partially open Throttle.

Fig. 1? shows acnematic the application of the invention Zumeßeyateiaa for only partially open throttle valve a double carburetor.

Figs. 1 and 2 show a Yergaser 10 which is on the suction line 12 a combustion power »aschi & e through suitable fastening devices, how bolt 14 »is attached. The carburetor can, for example, consist of an upper and lower part 16 and 18 exist, which are separated from one another by a seal 20 and are connected to one another by suitable fastening devices, for example screws 22. The upper and tuiteren Parts 16 and 17 of the carburetor 10 are shaped so that they form an intake duct 24, jlü which one on an axis 27 attached air flap, a venturi nozzle 28, a fuel injection nozzle 30, a throttle valve 32 and a draw tube 34 of a Kraftetoffreeervoirs are arranged. The Droseel flap 32 is pivotably mounted on a shaft 36. The fuel reservoir 38 can be formed directly in the upper and lower files 1b and 18 of the gasifier housing and may include a conventional float assembly 40 such as them

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is partially shown in Fig.3. This fuel reservoir 38 is in connection with the intake duct 24 via a draw tube 34 and is connected to the atmosphere via a continuously open vent 42 tied together.

As can be seen from FIG. 3, the fuel reservoir 38 also comprises the conventional metering nozzle 46 which is part of a line 48 which connects the fuel reservoir 38 to the main pipe 50 of the main metering system 52. If necessary, a main pipe 54 at 56 (FIG. 2) can be pressed into the upper part 16 of the carburetor 10 so that it protrudes into the main pipe 50. The main pipe 54 has several outlet openings 58 in its outer wall and is thus connected to the main pipe. chamber 50 in connection. In the embodiment shown, the upper end of the main pipe chamber 50 intersects a line 60 which is connected to the intake duct 24 via the main fuel nozzle 30.

The actual idle metering system 100 is shown in FIG. Me channels 102 and 104 in the lower rope 18 dee Vergaeere lead.-from the main pipe chamber 50 to a channel 106 in which an idle constriction 108 is arranged in the upper part 16 can be. Meöe constriction 108 is connected to the idle channel 11 © A second conference 112 was arranged in verbiad "ng" in weloheffi aar kana. via Kaaäl 110 verbinclei! a leeward outlet 114 a channel 116V ^ pear eewinäebohrung 118 iflt in the rope

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so provided that the inner end of this threaded hole communicates with channel 116.

As can be seen above all from FIG. 4, a narrowing opening 120, which is in extension of the threaded hole 118 is formed, a connection between the connecting portion of the channels 116 and 118 with the intake channel 24 in Direction of flow behind the throttle valve 32. An externally threaded sleeve 122 is in the threaded bore 118 screwed in so far that between the inner end of the Sleeve 122 and the bottom surface of the threaded hole .118 a predetermined Distance 124 remains. The sleeve 122 can, for example can be rotated by a socket head 125 formed at its outer end. The distance 124 limits the maximum fuel flow that can exist between the passage 116 and itself narrowing opening 120 may occur. If the desired Setting of the gap 124 is reached, the screwed in Sleeve 122 remains fixed in this position by suitable means, for example by a festteilstif-fc 126, the can be used through a transverse bore 128. The rest of the Opening 128 can then, if desired, be sealed by suitable measures. Instead of the locking pin 126 can 6 also a wall section 129 between the boreholes 128 and the sleeve 122 remain. In this case it can Wall section 129 into the thread with a pointed tool the sleeve 122 are pressed in, which in any case prevents further rotation of the sleeve Ϊ22.

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A manually adjustable screw 130 with a projection 132 is screwed into the threaded bore 118 such that this port set 122. durohragt through the central bore of the sleeve 132nd The extension 132 has a tip 134 which acts as a valve, the seat of which is formed by the narrowing section of the opening 120. A spring 136 is arranged between the head of the screw 130 and the outer stop surface 138 of the carburetor housing part 18.

As shown in FIG. 5, the sleeve 122 can also have a conical shape have tapered portion 140 at the inner end and the bore 118 can have a correspondingly tapered Have wall 142 at their inner end. The wall 142 can if necessary, be formed on a separately inserted part 143. A gap 144 between these two is conical tapering parts serves to limit the connection between the channel 116 and the narrowing opening 120, if one disregards the presence of the tip 134 of the screw extension 132. The functional difference between the exemplary embodiments according to FIG. 4 and FIG. 5 will be explained below.

The fuel from the fuel reservoir 38 via the Hauptzumeßäüse 46 5o entering in a known manner in the main pipe is at idle conditions, d * h _e at substantially the throttle valve 24, through the channels 102, 104, 106

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130 past brought 11Q and 11b, and then either via the gap 124 shown in Figure 4 or the b shown in Fig. Gap 144 at the end 132 of the Leerlaufeinstellsohraube into the intake passage 24th

The sleeve 122 can be screwed in and must be in the threaded hole 118 on the circumference of the extension 132 of the screw 130 in the bore 118 can be fastened, ao that the predetermined gap width 124 or 144 to maintain a predetermined maximum of force siofflusaes between the channel 11t> and the opening 120 is maintained. For a lower fuel flow, the screw 130 is adjusted by hand so that the Size of the opening between the tip 134 and the conical Section of the opening 120 is adjusted accordingly, the spring 136 serving to hold the screw in the position once selected.

Before going into the explanation of the mode of operation of the device according to the invention, it should be pointed out that the idling force flow is influenced by a large number of factors, for example by the size, the - .. Iffige "and the setting of the throttle valve, the size and the- Position of the transition slot, the size of all ducts in the idling system including the air inlet duct for idling ".."■; ■.. ■ ■ '.. "- .. V

909884/0591

The carburetor according to the invention is primarily intended to be used in motor vehicles that are used in areas which have strict regulations against air pollution by exhaust gases, although it seems logical at first glance would appear to use only an appropriately sized fuel nozzle, this is not compliance with a very specific idle fuel levels achieved within narrow limits, because in view of the normal manufacturing tolerances, a carburettor manufactured in this way can very easily be turned off its target limits fall. With such carburetors must therefore the maximum idle fuel flow for each individual during the final calibration, i.e. in the last stage of the carburetor production, can be precisely regulated. ■

This final calibration of a carburetor requires (aj first of all such an adjustment of the throttle valve that the predetermined Amount of air is supplied, (b) and that the idle screw is then removed and the carburetor is operated with the throttle valve in the closed position and it is determined whether the resulting maximum running fuel flow is the fuel-air ratio, which is within the limits determined by the regulations. It would be impractical to have an arrangement that may be required at this point in time by changing the size of the idle jet itself. Ea would also be impossible, for example

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wise to make this idle jet opening smaller by drilling. Accordingly, according to the invention, corresponding adjustable throttle devices must be provided.

The sleeve construction mentioned above forms a simple one and cheap means of compensating for any manufacturing tolerances of whatever nature, so that the maximum Fuel flow adjusted within the desired limits can be. According to the invention, this is achieved by that in the final setting simply twist it the sleeve in the usual manner with an internal thread Hole for the idle adjustment screw is carried out the desired setting and then the Sleeve in this position to maintain this maximum Setting is determined. If this sleeve once is set, it can no longer be solved without authorization or solve itself by vibrations. By the usual The idle setting screw is then only the setting of the idle fuel flow smaller within certain limits than this predetermined maximum fuel flow possible.

Once the sleeve is adjusted, the assembly according to flg. 4 by the smallest turn of the screw sleeve 122 within the threaded bore 118 a change in the axial Distance .124 enter. It has been found that after the Adjustment of the sleeve 122 by hand within the bore 118

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and thus the setting of the desired distance 124 by inserting the retaining pin 126 (Pig.4) against the outer surface of the sleeve 122 or due to the deformation of the wall section 129 (FIG. 6) to fix the sleeve 122, a slight twisting of this sleeve 122 occurs. If the maximum setting for the fuel flow to comply with a suitable fuel-air mixture is not very critical ", i.e. if very narrow limits do not have to be adhered to, then this slight movement of the sleeve 122 does not interfere. However, if in a certain application the maximum Fuel flow can be kept within very narrow limits must, for example, an idle-fuel-air ratio maintain on the order of 0.089 to 0.91, after adjusting the usual throttle stop (not shown) to the appropriate airflow, then would be the slightest movement caused by the onset of the pin 126 suffice to rotate the sleeve 122 according to Figure 4 either inwardly or outwardly that the Fuel flow through gap 124 outside the predetermined Limits. ^

As shown in Figure 5, the plane of the gap 144 is between the conical surfaces 140 and 142 not at right angles arranged to the axis of the bore 118 as the plane of the Gap 124 according to Figure 4 between the end face of the sleeve and the bottom surface of the hole. The gap 144 formed between

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the surfaces 140 and 142 is conical. In this manner, .a small rotation caused by the insertion of the pin 126 or the buckling of the wall portion 129 against the outer surface of the sleeve 122, the axial position of Endabeohnittes 140 precisely as far as the sleeve 122 _f according to Figure 4 will change, however, it can be seen that the effective perpendicular distance between the conical surfaces 140 and 142 changes much less.

In mathematical terms, this means that at an angle A according to FIG. 7 of, for example, 7.5 ° with an axial movement of the sleeve 122, the perpendicular distance between the parallel conical surfaces 140 and 142 is only one eighth of the vertical distance between the two inclined surfaces changes. They same small change that the gap 124 brings according to Figure 4 outside the predetermined limits, generated alβο no exceeding the limits of the desired Kraftatofflusee at the conical gap 144 according to FIG. 5, there

the fractional effect of a vertical movement is exploited . ". ^: .; ■ '■■■■;.'.;■■■■■; .-

It should be noted that both the rectangular sleeve 122 according to Fig * 4 as well as the conical sleeve 122 together with the associated Seat part 143 according to Figure 5 also with each ready existing one Carburettor can be used that previously had no devices to limit the maximum idle fuel

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the river. It can also be seen that after installation and sealing, each del? above embodiments accidental or unauthorized changes to the setting are avoided.

FIG. 8 shows a further embodiment from the setting device shown according to Figure 5, the conical design here the sleeve is made inside.

In the exemplary embodiment shown in FIGS. 9 to 12 for an inventive design of an idle fuel system has the threaded hole 118 des Part 18 near the channel 116 an inner extension 119 ■ of smaller diameter, which the narrowing öff-> opening 120 in the intake duct 24 in the direction of flow the throttle valve 32 forms.

A manually adjustable vision hood 152 with an extension 154 is screwed into the threaded hole in such a way that this Extension 154 protrudes into the calibration-narrowing opening 120. The extension 154 produces a pointed land-156-, the together with the conically tapering one that acts as a yentil seat Section of the opening 120 acts. A spring 158 is between the head of the screw 152 * m & a stop or the surface 160 of the part 118 for maintaining a predetermined ii Tension of the thread provided.

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According to Pig. 11 is a second threaded hole 162 in the housing part 18 formed in the embodiment shown beis' |) iel perpendicular to the threaded hole 118. A port 164 of this threaded hole 162 of smaller diameter it first encompasses the vertical channel 116 and then the channel section 119 of smaller diameter of the threaded hole 118 near the narrowing opening 120. A second Hand adjustable screw 166 with a slot 168 on the outer end is screwed into the threaded hole 162 and the outer portion of this threaded hole 162 can then be filled with a suitable material, for example with a putty 169 (Pig.12).

A smaller diameter port set 170 of screw 166 with a pointed end 172 protrudes into the channel 116. In the underside of the carburetor part 118 is a channel 174 of relatively small diameter and a predetermined one Depth close to and perpendicular to the threaded hole 162 is formed.

As already described above, fuel that is discharged from the fuel reservoir 38 via the main metering nozzle 46 enters the Main pipe 50 enters, when idling, i.e. when the throttle valve 24 is essentially closed through the channels 102, 104, 106, 110, 116, 164 and 119 and then through the narrowing opening 120 into the intake channel 24.

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To a τ or certain limitation of the maximum fuel flow To reach between the channel 116 and the opening 120, the screw 166 is screwed into the bore 162 is initially set and then fixed therein so that the pointed end 172 narrows the channel 116. For any lower fuel flow desired, the other screw 152 is manually adjusted to the size of the To adjust the outlet opening or the gap between the pointed end 156 and the conical section of the opening 120, wherein in turn, the spring 158 to hold the screw 152 in the once set is used.

As already mentioned above, the final adjustment of a carburetor of the known type has always been a) the setting of the throttle valve 32 for the entry of a predetermined amount of air when the throttle valve is completely closed, b) the removal of the normal simple idle adjustment screw 152 from the opening 120 and c ) operation of the carburetor with the throttle valve 32 closed has been required to see if the resulting maximum idle fuel flow gives an air-fuel ratio that is within regulatory limits. ± is impractical _f if any necessary adjustment would be performed in this time, by changing the size of the idle jet 120 itself. If the fuel flow were too large, it was not at all possible to make the opening 120 smaller by further machining measures. This is only through the inventive

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Measure possible, namely to provide two idle adjustment screws. By the arrangement near the invention it is possible, the actual setting during the final calibration of the carburetor in a simple manner by turning the screw 16b within the threaded) hole 15 ^ to carry out until the maximum desired fuel-air mixture, for example in the order of magnitude between 0.098 and 0.091 is.

Once the screw 166 is adjusted by hand, what for example in a simple way by inserting a Screwdriver into the contactor 166 can be done a suitable piercing tool is inserted into the opening 174 and pressed against the wall section near the threaded hole 162, so d & b this wall section against screw 166 is deformed and so the screw is fixed. if the screw 166 is fixed in this way, the remaining bore hole above the slotted screw head becomes with a suitable material, e.g. a putty 169, filled so that the screw 166 thereupon is inaccessible and protected from improper operation. The putty 169 can also act as a sealant against the leakage of liquid through the screw 166 and in some cases a putty material can be used / through which the screw 166, without the insertion opening 174, in its position once it has been chosen. At the

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At the end of the channel 116 (FIGS. 10 and 12) there can also be a plug 176 close to prevent fluid leakage the intake pipe 12 may be provided.

Also that according to the invention shown in FIGS. 9 to 12 Embodiment of an idle fuel flow system allows very precise setting of the maximum idle fuel Stromes and enables a very simple end setting of carburetors. Since each carburetor has to be adjusted separately, the manufacturing costs are reduced in this way due to the shortening of the setting time degraded »The arrangement of two separate Adjustment screws enable very quick and easy adjustment. -

In addition to setting the idle fuel flow, also with the Auepuffgasbeschränkuag of internal combustion engines control of the fuel metering is often required when the throttle valve is only partially open. In the figures 15 to 17 is the device for such a metering system for only partially open throttle valve on the basis of a modified one AusfÜhrungsbelßspiels a carburetor 210 shown, e.g. in connection with a fuel measuring system of a Carburetor 10 can be used *

Fig * 13 shows a carburetor 210, which is on an Aaeaugleitung 212 in a suitable manner, for example by bolts

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214 is attached. The carburetor 210 is designed so that it has an intake duct 216, which is a usual on a Shaft 220 attached air damper, a venturi 222, a Main fuel nozzle 224 as well as a throttle valve 226 fastened on a shaft 220 and a fuel reservoir 230 includes. The fuel reservoir 230 includes the usual float arrangement 232.

As can also be seen from FIG. 13, this includes fuel reservoir 230 the usual main metering nozzle 234, the one Part of the line 236 forms the reservoir 230 and the Main pipe 238 of the main metering system 240 connects. If If necessary, the main pipe 242 can by any suitable means be attached so that it protrudes into the main pipe 238. The main pipe 242 has a plurality of outlet openings 244 in its wall, with which air via an inlet 246 at the top of tube 242 into main tube chamber 238 is fed. In the embodiment shown, the upper portion of the main tube chamber 238 intersects a conduit 248, which via the outlet nozzle 224 with the intake duct 216 communicates. '. ... "

Various typical ones are also shown in FIGS. 13 to 15 Facilities for fuel enrichment shown. In the embodiments according to FIGS. 13 and 14 are dependent Devices actuated by the vacuum and in Fig. 15 a mechanically actuated device is shown. That

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System 250 shown in Figure 13 includes a membrane 252 which the movable partition between the fuel chamber 254 and the air chamber 256 forms. A channel 258 connects that Fuel reservoir 230 with chamber 254 and a channel with a calibrated restriction 262 leads from the chamber 254 to the main pipe chamber 238. A channel 264 stands at a lower level Air chamber 256 and a portion of the intake passage 216 below the closed throttle valve in connection.

The narrowing end 266 of the channel 258 serves as a valve seat for a valve 268 with a stem 270, which extends through channel 258 and in any suitable manner is connected to the center of the diaphragm 252. Between the reservoir wall and the shoulder 274 formed at the end of the valve 268 is a leather 272 that supports the valve 268 is always biased away from the seat 266. '

When the throttle is completely or only partially closed » flap and high negative pressure in the suction line, the pressure difference on the membrane 252 is such, in a known manner, that the valve 268 is pressed down against the seat 266 against the spring 272 »When the throttle valve is reinforced at Power is opened and the negative pressure in the suction line is less, for example less than 20 cm of mercury, the pressure difference across the diaphragm 252 decreases to a point where the spring 272 closes the valve

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268 lifts from Sitz266, so that a connection between the fuel reservoir 230 and the main tube chamber is made 238, and thus, additional fuel for generating the increased power to the main pipe supplied by the Zumeßeinschnürung 262 ^1. ■

The piston-based enrichment system 276 shown in Pig. 14 comprises a channel 278 which, like the channel 264 of FIG. 3, establishes a connection between the aspiration channel 216 and the chamber 280 in which the piston 282 slides. From the piston 282, a shaft 284 with a spring holder 286 protrudes downward at the end through an opening 268 into the fuel reservoir 230. A spring 290 is arranged between the reservoir wall in the vicinity of the opening 288 and the holder 286.

In a chamber 294, which is connected to the chamber 254 according to FIG is comparable, a valve 292 is arranged. One within spring 296 attached to chamber 294 biases the valve 292 in RiofrGuMg on the valve seat 298 at the end of the channel 300, which is comparable to the channel 258 according to FIG. A push rod 302 protrudes upward from the valve 292 and extends through channel 300 into reservoir 230 to near holder 286. Same as in Pig. 13 works with sufficient Redti ^ decoration of the imter pressure in the chamber 280 above the KoI feen-s " 282 the differential pressure at the piston such that through the Spring 290 of piston 282 and thus also of pushrods 284 and

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the holder 286 down in contact with the valve stem 302 is depressed, opening valve 292 and delivering the desired additional amount of fuel.

The enrichment system 304 shown in Figure 15, which is similar which acts according to Fig.14, is through a connecting rod 306 actuated, which the ram 308 vertically in dependence .from a rotary movement of the throttle valve shaft 228 (Fig. 13) moved, with which latter the linkage 306 to appropriate Way communicates.

The normal manufacturing tolerances of the carburetor parts Arrangement according to Fig.13 to 15 are generally such that the curve for a partially open throttle of a given carburetor is usually somewhere in a comparatively wide range between those dotted with the dashed lines Curves A and B according to Fig. 16 have certain limits lies. This means that changes in dimensions are allowed of the drilled channels 234 »262, 244» 246 »224 and 222 in making a resulting curve for partial open throttle, which within relative large limits, for example curves A and B, lie. For various exhaust gas regulations, this fluctuation range A-I is not acceptable, therefore an additional fuel system 310 (see Pig. 13) is required. provided by which the limits within which the Curve for only partially open throttle falls, 'ge.-'

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can be adhered to more precisely. This area is shown in Fig. 16 indicated by the dashed lines ο and d. In this way, the fuel-air mixture that is used for any particular carburetor with the throttle only half open is fed, never be so rich that a predetermined permissible hydrocarbon exhaust quantity exceeded will, and will never be too lean to affect engine operation.

The mode of operation of the auxiliary fuel system 310 is explained in more detail below. There are additional funds for the connection between the fuel chamber 254 (or the Chamber 294 according to FIG. 14) and the fuel reservoir 230 are provided. It is a channel 312, one Constriction 314 and an intermediate channel section or a chamber 316, the outer section of which is threaded is provided. In this chamber 316 is an adjustment screw 318 of the kind screwed in that by a conical end 320 the size of the constriction can be changed. The screw is adjusted once 318 by suitable means, for example by piercing or filling in the upper portion of the channel. 316 close the slotted head of screw 318 with a suitable Material, for example a sealing wax or the like., Set.

According to the invention there is an undersized main metering nozzle

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234 is chosen to ensure that the resulting air-fuel ratio a curve for only partially open throttle is generated, the maintenance) of the dashed line Line D according to Fig. 16 lies. When finalizing the carburetor adjustment, the adjustable screw 318 is first turned back very close to the constriction 314 and then outwards away from this constriction 314 until there is enough additional fuel through the channel 312 at the conical end 320 over into the chamber 254 (or the chamber 294 in Pig. 14) and then through the fixed constriction 262 in the main pipe. 238 arrives, so that for only partially open throttle valve desired curve of the diagram fuel-air ratio / air flow in the through-ch the dashed lines C and D given limits, soft represent the still wearable area.

In order to achieve that the entire fuel IuS with fully open throttle valve and open valve 268 of the is the same as in the carburetor without the auxiliary fuel system 310, the constriction 262 of the power valve channel becomes somewhat chosen to be larger than usual and it should be remembered that the main metering nozzle 234 was chosen to be about »smaller than usual. This will take the total amount of fuel, which when fully open Throttle through the main metering nozzle 234 and through the parallel channels with the common constriction 262 either one or both parallel channels 2i> 8 and 312/314 fed

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will, essentially, be just as great as with the ones so far usual sjtitemen.

Of course, the assistant system 310 may as well are used in carburetors with an enrichment system 2/6 and 304 according to FIGS. 14 and 15 are provided. .

Through the use of a fuel control assist system 310

is due to the possibility of a quick and easy}

Setting during the final calibration of each carburetor 210 a \

Possibility created by which the curve for only 1

partially open throttle valves within very narrow limits

without the need to adhere to very tight - \

Product tolerances can be maintained. With the lower I.

... ■■. ■■ "■■■ ϊ

Upper Grense C for the lurve when only partially open Throttle valve instead of the much higher lying upper one: Limit A according to the known carburetors can be the required; strict regulations to keep the air clean in a simple manner be respected. Even so, the operation of the carburetor

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not affected when the Droisel flap is fully open «

'. Pig. 1.7 seleaatically shows the application of the invention to one Double carburetor, the same parts being provided with the same reference numerals as in the exemplary embodiment according to FIGS. 13-15. In the dual carburetor applications, there are two main pipes 238, two main nozzles 234 and two fixed cone

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stanchions 262 provided through which the pipeline system. with the single power valve 268 and the auxiliary system with the single hand adjustable screw 518 directs fuel to the main pipes. The auxiliary fuel is closed when the Power valve and line fuel is nattir borrowed evenly divided by the fixed constrictions 262, so that only a single screw 518 is required. As with a simple carburetor, the area for only partially open! throttle valve of the main fuel system terns can be regulated much more precisely without affecting the operation with the throttle valve fully open. becomes «" "■" "■

Claims

BATH

909884/0591

Claims (9)

r. . . ■■ - ■ π PATENTANWÄLTE DiPL-INQ. F. THIELEKE "Q ■" .... pHYS nR, FR1CKE DR-INQ. R. DÖRING J "} DIPL.-PHYS. DR. J. FRICKE BRAUNSCHWEIG MUNICH Holley Carburetor Comp.. ■■■■ · ■ 11 289 September 22nd, 196g- 'Pat corresponded e 1. A method for adjusting the specific maximum value which the air / fuel ratio during idling in an internal combustion engine having a carburetor, wherein an intake port with the throttle valve and an idle system comprising a fuel transfer _y in a into the intake passage on the internal combustion engine facing side of the throttle valve opens, which is assigned a manually adjustable adjusting screw that controls the opening passage, thereby, geke η η ze ic h η et »that first the throttle valve is set for the air flow required in idle through the carburetor, whereupon in Direction of flow behind the fuel transfer, the fuel flow is immovably limited to a fixed maximum value in such a way that the fuel / air ratio can only be set to values below the maximum value determined by the maximum fuel flow by means of the adjusting screw, 2. Method according to .Anspruch 1, thereby g e k β η η « ^L. '■■ .-. BAD ORKMNAL-. _90fl8 g _{A / 05} g _r J Documents (Art. 7 § 1 Para. 2 No. 1 Clause 3 of the amendment Bgee. V. « indicates that before the limitation of the fuel flow, " to the maximum value, the adjustment resistor is brought into a position that does not affect the opening passage. 3. Carburetor for internal combustion engines for Auefführung the method according to claim 1 or 2, Mt a fuel • »• storage space, an air intake duct with throttle valve © and an idle system with a fuel transfer from the storage space to the air intake duct below the throttle valve, characterized in that the Fuel transfer a limiting device (122) that can be initially set and subsequently blocked against adjustment to limit the fuel flow to a maximum value by means of the fuel transfer, and thus an adjusting device (130) that can be adjusted by hand for changing the fuel flow in the range below the limited maximum Value are assigned. 4. Carburetor according to claim 3, in which the fuel enters the air intake duct via a fixed opening below the throttle valve, thereby geke η η ζ calibrated net, that the fuel transfer has at least one transfer passage, which in the flow direction above the fixed opening (120) in the Ameaugkanal is discharged and fed by the fuel transfer, wnd that the -limitationsin-. direction (122 or 166,170) in "8tr0imragerlchtung Mater the ÜberfÜhrungsdurehlaß is arranged. -909884/0591 ^BAD 5. Carburetor naoh claim. 3 or 4, thereby g e k β η η ze i without t that the set limiting device 022 or 166,170) is inaccessibly covered (screw 118, Biohtmasae 164). 6, carburetor according to claim 3 to 5, characterized in that g e k e η η ζ ei ο h η @ t that the limiting device has one through Broeael adjustable sofa element is « 7 «Carburetor according to claim 4 to 6, characterized geke η η, - μ e 1 ο h net that between the fixed opening (120) and the limiting _{device (122 or e} 166,170) the fuel transfer is free of throttle parts or into the Intake ducts opening openings is such that the fuel flow management of the transfer passage is essentially unaffected by the curtain device. 8. TQrgaser according to claim 3 to 7, characterized ge ken n> ζ e i h a. et that the limiting device (122) and the adjusting device (130) comprise coaxial elements, one of which is formed by a threaded bushing (122), which can be inserted into a threaded hole coaxial with the fixed opening (120) and with its end the inflow cross-section determined to the opening (120). 9. Carburetor according to claim 8, characterized ge kenn - SS84 / 0 591