US3081757A - Multi-stage governed fuel device - Google Patents

Description

March 19, 1963 1'. F. CRAMER MULTI-STAGE GovERNEn FUEL DEVICE 2 Sheets-Sheet l Filed April 7, 1958 March 19, 1963 T. F. CRAMER 3,081,757

MULTI-STAGE GovERNED FUEL DEVICE Filed April v, 1,958 2 sheets-sheet 2 /38 5 1N VENTOR.

Efo/ms ffm/V15@ ,4 TTOEA/E Y @hired biases iiatenr fiila? Fatented Mar. I9, 1963 hee 3,081,757 MULTI-STAGE GVERNED FUEL DEVISE Thomas F. Cramer, Warren, Erich., assigner to iioiiey Carburetor Company, Van lllyhe, Mich., a corporation of Michigan Filed Apr. 7, i958, Ser. No. 726,773 3 Claims. (Cl. I23-It3) This invention relates to governors for internal combustion engines, and more particularly to governors for internal combustion engines requiring dual or multi-stage carburetion.

Increasing horse power of automotive internal combustion engines has necessitated the use of two-stage carburetion as provided by the well known two or four barrel carburetor in which the throttle plate (or plates) controlling the i'low of fuel-air mixture through the primary barrel (or barrels) is manually operated land the secondary throttle plate (or plates) is automatically opened against a spring tending to hold it closed by a suction device having a diaphragm actuated by primary and/ or secondary venturi vacuum. The secondary barrels thus supplement the primary barrels when the capacity of the latter is exceeded.

In truck or other applications where it is desired to govern the speed of the engine and/or the speed of the vehicle, a second suction device actuated by primary venturi and/ or manifold vacuum is provided to override the manual operation of and to close the primary throttle plate or plates, the intensity of the governing vacuum being controlled by a speed sensitive valve adapted to close an air bleed when the governed engine iand/ or vehicle speed is reached.

It has been found, however, that governor performance becomes erratic just slightly after governing action takes place. This is because the secondary throttle plates, which may be fully `open at the start of governing, do not close rapidly enough. Therefore, the primary throttles will over-close before the secondary throttles fully respond to the change in air flow past the carburetor venturi.

It is now proposed to provide a governor system for an internal combustion engine utilizing dual or multistage carburetion which will be free of the above objections to present governors. This is accomplished in the present embodiment of the invention by connecting the vacuum effective to positively close the primary throttle plates when governed speed is reached to a pressure responsive valve which will in turn bleed atmospheric pressure into the vacuum side of the isecondary throttle diaphragm assembly, thus causing the secondary throttlcs to close with or ahead of the primary throttles.

In the drawings:

FIGURE 1 is a side elevational view with portions thereof in cross section of a four-barrel carburetor provided with -a governor embodying the invention;

FIGURE la is a schematic illustration of a vehicle engine and transmission illustrating the manner in which the governor control valve may be connected;

FIGURE 2 is a side elevational view, with portions thereof in cross section, taken on the plane of line 2-2 `of FIGURE l and looking inthe direction of the arrows;

FIGURE 3 is a cross sectional view taken on the plane of line 3--3 of FIGURE l and looking in the direction of the arrows;

FIGURE 4 is a bottom plan view taken on the plane of line '4 4 of FIGURE 1 and looking in the direction of the arrows; FIGURE 4 illustrates the manner in which the carburetor shown by FIGURE l is cut away to illustrate the primary and secondary throttle plates.

FIGURE 5 is a vertical cross-sectional View taken through the axis of the element shown in elevation at the bottom of FIGURE 1.

Referring now to FIGURE l, a four-barrel carburetor It? of the type referred to above and having an air intake I2 is cut away as shown by FIGURE 4 to expose one of the primary barrels I4 and one of the Secondary barrels 16. The primary barrel 14tis provided with :a restriction or venturi I8 and' a manually operated throttle plate 20 mounted on the shaft 22 which extends thi-tough the other primary barrel in which is mounted a 'throttle plate identical to throttle plate '20. The secondary barrel 16 is also provided with a venturi Z4 and `a throttle plate 26 mounted on the shaft 28 which extends through the other secondary barrel in which is mounted another secondary plate.

While a particular four-barrel carburetor is shown for purposes of illustration, it will be apparent that the invention is equally applicable to two-barrel or other multistage carburetorS.

A suction device Sil commonly referred to as a governor diaphragm assembly is mounted on the boss 32 and gasket 33 extending fnom the carburetor throttle body 34. The assembly 3b includes a casting or other body 36 formed to provide recesses 35 and di?. The recess 46" is covered by means of a ilexible diaphragm 4Z which is secured to the body 36 by means of `a cover member 44.'- formed to provide an air 'tight chamber d6 of which the exible diaphragm 42 forms a wall. 'Ihe cover member may be secured by any suitable means such as screws 47.

As shown by FIGURES 1 and 2, the diaphragm 42 has secured to the center thereof in the conventional manner a rod 48 passing through passages 50 in the body 36 and having a laterally extending end 52 pivotally secured to the lever 54 which is rigidly secured to the end S6 of the primary throttle shaft 22 extending into the chamber 38. The shaft 22 is mounted in the antifriction bearing 39, and -a spring 41 is disposed between the bearing 39 and the steel yand leather washers 43 and i5 to provide a seal. A tension spring 58 fixed between the Iadjust-able pin 64I mounted in one of 'the holes 62 in the body 36 and the xed pin 64 secured to the lever 54 tends to hold the primary throttle plate 2d in the open position lso long :as and to the degree that the usuai foot 'throttle (not shown) is depressed. This is accomplished by a well known dog clutch arrangement, which is not shown since it does not constitute any part of the invention and which permits governor action described below to override the foot throttle control. An atmospherically vented cover plate 66 may be secured by screws 68' to housing 36 thereby protecting the mechanism within chamber 38 The orifice 72 at the primary venturi vI8 and the oriiice 74 below the primary `throttle plate 2d are connected by means of the passages 76 and 78 having fixed restrictions 80 land 82 respectively with the passage S4 in the body member 36 and the passage 86 in the cover member 44 which lead to the chamber 46. A passage 88- connecting with passage 84 terminates in an opening in the body 36 adapted to receive a threaded fitting 90.

Located :at any desired position on the engine is a governor valve assembly 92 comprising a stationary housing 94- adapted to be mounted on the engine and containing `a shaft 96 driven in yany suitable manner in proportion to engine or vehicle speed. This alternative drive is illustrated by FIGURE la wherein the shaft 96 of governor valve assembly 92 may be connected to be driven either by the engine 93l through a drive A or by the transmission (vehicle speed) through a drive B. Mounted for rotation wit-l1 the shaft 9d is a laterally extending sleeve 93 having ia spring Idd mounted within the axial passage 1452 in the sleeve in any suitable manner, such las in the internally threaded member idd, so that the spring litl is ast-51,757

adjustable axially by means of the adjustment screw 106 which is reached by removing the access screw 1081. The other-vend of the spring 161) is secured to the governor weight 111i movable axially within the chamber 112 against the .spring i? and having at the free end thereof a valve 114 adapted to close the orifice 116 when the weight 110 is forced outwardly due to the rotation of the shaft S16-and the sleeve 98 in accordance with the engine speed. The engine or vehicle speed at which the orifice 1116 will be closed is dependent, of course, upon the adjustment of the spring 11th. 1t is apparent, also, that some other governor valve structure may be employed.

Conduit 118 between the air intake 12 of the carburetor 1t) and the housing 94 and conduit 122 between the housing 94 and the passage 88 in the body 36 are provided so that when the engine or vehicle is operating :at -a speed not sufficient to close the orifice 116, engine vacuum will draw clean air through the conduit 115, into the housing 94, through the `orifice 116 and into the chamber 112, through the passage 1112 and the axial passage 120l in the shaft 96 and thence through the conduit 122 to the governor diaphragm assembly 3). When the engine reaches governed speed, the oriiice 116 is closed and the `air bleed through conduit 122 is cut otf. When this occurs, vacuum in the chamber 46 urges the diaphragm 4t2 downwardly, as in FIGURE 2, against [the spring 58 to close the primary thnottle plates 29.

A secondary throttle diaphragm assembly 124iL is mounted at the opposite side of the throttle body 34. This assembly comprises a body 126 having a recess 128` vented to the atmosphere through a plate 130` secured by screws 132 and a recess 134 olosed by a flexible diaphragm 136 which is secured to the body 126 by means of a cover 138 formed to provide `oppositely disposed chambers 141i/ and 142 between which the iiexible diaphragm 136 forms a movable wall. The chamber 142 contains a compression :spring 144 positioned between the cover 138` and the rod `146, which is secured to the center of the diaphragm 136, so that the spring 144 urges the rod 146 upwardly to rotate the lever 14S secured rigidly to the secondan throttle shaft 2S counter-clockwise, as in FIGURE 3, and close the secondary throttle plates 26. A conduit 150 extending between the chamber 142 and the vacuum passages 152 and 154 opening to the primary and secondary venturis `13 and 2d enables primary and/or secondary venturi vacuum to evacuate the chamber 142 and displace the diaphragm 136 downwardly, as in FIGURE 1, against the spring 144 to open the secondary throttle 26. The force of the spring 144 is selected so that the secondary throttle plate 26 will start to open at any predetermined venturi vacuum.

The structure described above, or its equivalents, is well known in the art, and proper governing action depends upon the particular degree of closing of the throttle plates 20 and 26 when the engine or vehicle has reached a predetermined governing speed `so as to diminish or cut off the how of motive fluid to the engine. However, in the case of dual carburetion as described above, the automatic closing of the secondary throttle plates 26 lags behind that of the prima-ry throttle plates 20, particularly at governed engine speeds at which the secondary plates 26 are not fully open so that linkage (not shown) usually effective to positively close the secondary plates 26 with the primary plates 20 does not come into operation. While this is desirable or tolerable in the normal function of the dual carburetor whereby during acceleration additional fuel-air mixture is supplied to the engine when the primary barrels have reached their capacity, it is highly objectionable for the purposes of governing, since uncontrollable amounts of excessive motive uid may continue to be supplied through the secondary barrels 16 for some period of time after the primary barrels 14 have been partially closed. This causes hunting, since the primary throttle plates have to linst close farther than would otherwise be required to compensate for the open secondary 1 plates and then open when the secondary plates finally close.

In order to remedy this objection, a pressure responsive bleed v-alve assembly 158 is connected to chamber 142 of diaphragm assembly 124. The bleed valve assembly 15S is comprised of a body portion 161i having therein a generally cylindrical cavity 162 having formed therein a valve seat 164- comprising a suitable projection 166 which also divides the cavity into separate chambers 182 and 184. A valve member 168, operatively connected to a stem 170, is adapted to coact with the seat 164 so as to at times prevent ow therethrough. The body is suitably secured to a diaphragm assembly having a housing 172 in which a diaphragm i174 is secured to form chambers 176 and 178. The chamber 178i contains a spring 180 normally biasing the diaphragm 174 to the left and is subjected to governor vacuum, while chamber 176 is suitably vented to the atmosphere. An internally threaded projection 186 on housing `172 may be adapted to receive conduit 156 which leads from the vacuum conduit 122. A second internally threaded projection 188 formed on body 16@ receives conduit 15d in such a manner so as to be in communication with chambers 182` and 142. Chamber 184 is normally vented to the atmosphere by means of a calibrated restriction 1%.

With the above construction, the operation tof the invention is readily apparent. Whenever governed speed is reached, the engine vacuum is employed to close the primary throttles 2G; at the same time this vacuum is directed to chamber 17 8l, causing the stern 174i` and valve 163 to move otf of seat 164. This permits atmospheric pressure to be bled into chambers 182 and 1412 through restriction 19t?, thereby reducing the vacuum in chamber 142 and permitting the spring 144 to close the secondary throtles 26 `ahead of the primary throttles 2li. Such closing of the secondary throttle plates eliminates the objections discussed above.

While but one embodiment of the invention is disclosed, it is to be understood that other modifications may be made and that no limitations not necessitated by the following claims fare intended.

What I claim is:

l. In a carburetor 'for an internal combustion engine having primary and secondary induction passages with venturis formed therein, throttle valves controlling the flow of combustible mixture through said passages, first pressure responsive means responsive to the vacuum created at said primary venturi for controlling the position of said secondary throttle valves, second pressure responsive means responsive to both primary venturi vacuum and engine vacuum for limiting the degree to which said primary throttles may be opened, and third pressure responsive means arranged in parallel with said second pressure responsive means for at times increasing the pressure within said first pressure responsive means.

2. In an internal combustion engine, a primary intake passage having a venturi and a throttle valve for controlling the flow of motive iluid therethrough, a secondary intake passage having a venturi and a throttle valve therein, resilient means for normally holding said secondary throttle valve closed, a first suction device actuated in part by primary venturi intake vacuum for opening said secondary throttle valve against said resilient means, a vacuum governor including a second suction device actuated by primary venturi intake vacuum for closing said primary throttle valve, a third suction device actuated by the same vacuum as said second suction device, said third suction device having means when actuated for rendering said rst suction device inoperative, a speed responsive bleed valve for rendering said second and third suction devices inoperative at speeds below governed speed, and operative at speeds above governed speed to allow said resilient means to close said secondary throttle valve at the same time as said primary throttle valve is closed by said governor.

3. A vacuum governor for controlling the speed of an internal combustion engine having primary and secondary intake passages, each of said intake passages having a throttle valve for controlling the flow of motive fluid therethrough, 4comprising a first suction device actuated 5 by primary intake and/ or engine manifold vacuum for closing said primary throttle valve when said engine reaches governing speed, a second suction device actuated in part `by Secondary intake vacuum for opening said secondary throttle valve, said secondary throttle valve being normally closed by resilient means opposing said second suction device, a third suction device actuated by the same vacuum Ias said first suction device, and said third suction device being adapted by its connection to said second suction device to render vsaid second suction device inoperative and to allow said resilient means to close said secondary throttle valve simultaneously with said primary throttle valve when said engine reache-s governing speed.

References Cited in the file of this patent UNITED STATES PATENTS 2,399,080 Udale Apr. 23, 1946 2,431,816 Mallory Dec. 2, 1947 2,452,698 Stre'binger Nov. 2, 1948 2,708,979 Reynoldson May 24, 1955 2,766,024 Smitley et al. Oct. 9, 1956 2,783,032l Carlson et al. Feb. 26, 1957

Claims (1)

1. 2. IN AN INTERNAL COMBUSTION ENGINE, A PRIMARY INTAKE PASSAGE HAVING A VENTURI AND A THROTTLE VALVE FOR CONTROLLING THE FLOW OF MOTIVE FLUID THERETHROUGH, A SECONDARY INTAKE PASSAGE HAVING A VENTURI AND A THROTTLE VALVE THEREIN, RESILIENT MEANS FOR NORMALLY HOLDING SAID SECONDARY THROTTLE VALVE CLOSED, A FIRST SUCTION DEVICE ACTUATED IN PART BY PRIMARY VENTURI INTAKE VACUUM FOR OPENING SAID SECONDARY THROTTLE VALVE AGAINST SAID RESILIENT MEANS, A VACUUM GOVERNOR INCLUDING A SECOND SUCTION DEVICE ACTUATED BY PRIMARY VENTURI INTAKE VACUUM FOR CLOSING SAID PRIMARY THROTTLE VALVE, A THIRD SUCTION DEVICE ACTUATED BY THE SAME VACUUM AS SAID SECOND SUCTION DEVICE, SAID THIRD SUCTION DEVICE HAVING MEANS WHEN ACTUATED FOR RENDERING SAID FIRST SUCTION DEVICE INOPERATIVE, A SPEED RESPONSIVE BLEED VALVE FOR RENDERING SAID SECOND AND THIRD SUCTION DEVICES INOPERATIVE AT SPEEDS BELOW GOVERNED SPEED, AND OPERATIVE AT SPEEDS ABOVE GOVERNED SPEED TO ALLOW SAID RESILIENT MEANS TO CLOSE SAID SECONDARY THROTTLE VALVE AT THE SAME TIME AS SAID PRIMARY THROTTLE VALVE IS CLOSED BY SAID GOVERNOR.

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