US3246886A - Charge forming device enrichment mechanism - Google Patents

Description

April 1966 c. R. GOODYEAR ETAL 3,246,886

CHARGE FORMING DEVICE ENRICHMENT MECHANISM Filed March 7, 1963 2 Sheets-Sheet l I Hlll] (l/4R4 3 1?. 6 o 00 new? Roy 14 M C dlsrs/vr INVENTORS BY diff; a. Zmw.

United States Patent 3,246,886 CHARGE FORMING DEVICE ENRICHMENT MECHANISM Charles R. Goodyear, Franklin, and Roy W. McSeveny,

Garden City, Mich, assignors to Ford Motor Company, Dearlborn, Mich, a corporation of Delaware Filed Mar. 7, 1963, Ser. No. 263,613 7 Claims. (Cl. 261-39) This invention relates to a charge forming device for an internal combustion engine and more particularly to an enrichment mechanism that provides additional fuel for the starting and running of a cold engine and also provides supplementary fuel to satisfy increased power demands.

The necessity of providing an enriched fuel air mixture to facilitate the starting of a cold engine is well known. It is also a common expedient to continue to furnish a rich mixture during the period of engine warm-up to promote smooth operation and to prevent stalling.

Although an automatic or manually operated choke valve is one common expedient employed for producing the desired cold weather mixture, this invention is concerned with charge forming devices of the type that embody supplementary fuel discharge devices for cold weather operation and starting. One common charge forming. device of this type includes an auxiliary induction passage that communicates with the engines intake manifold through the primary induction passage, posterior to the throttle valve. A thermally responsive valve controls the flow of air through the auxiliary induction passage to provide an increased, supplemental air flow at low engine temperatures. Fuel is also discharged into the auxiliary induction passage to provide the enriched mixture required for cold weather running. The described type of device frequently includes a still further enrichment device that discharges additional fuel into the auxiliary induction passage during the cranking of a cold engine to .promote rapid starting. Because of the complexity and attendant cost of the previously known charge forming devices of this type, they have enjoyed only limited application.

It is, therefore, an object of this invention to provide a charge forming device having a simplified cold weather enrichment device.

The charge forming devices of motor vehicle engines frequently have a power valve in the main fuel discharge circuit. The power valve increases the flow of fuel to satisfy the fuel requirements at higher power outputs.

The power valve is responsive to intake manifold vacuum inasmuch as a decrease in intake manifold vacuum occurs at times of high power demand. The power valve has been entirely separate from the cold Weather enrichment device, heretofore.

It is a further object of this invention to simplify a charge forming device by incorporating the power valve function into the cold weather enrichment device.

A charge forming device embodying this invention has, in addition to the conventional primaiy induction passage, an auxiliary induction passage. A thermally responsive valve member is positioned in the auxiliary induction passage to "control the flow therethrough. Fuel may flow from a supplementary fuel discharge into the auxiliary induction passage when intake manifold vacuum is low and regardless of the engines temperature.

A supplementary fuel discharge constructed in accordance with this invention is responsive to intake manifold vacuum to permit fuel flow when intake manifold vacuum is low, either during cranking or during periods of high power output. The supplementary fuel discharge may also be temperature responsive to vary the rate of 3,245,885 Patented Apr. 19, 1966 auxiliary fuel discharge in response to the engine temperature.

Further objects and advantages of this invention will become more apparent as this description proceeds particularly when considered in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a cross sectional view taken through the induction passages of a charge forming device embodying this invention.

FIGURE 2 is an enlarged view of the encircled portion of FIGURE 1 showing the enrichment device as it appears when the engine is cold and is being cranked for starting.

FIGURE 3 is a cross sectional view taken along line 33 of FIGURE 2.

FIGURE 4 is an enlarged view, in part similar to FIG- URE 2, illustrating the enrichment device as it appears during power operation when the engine has reached its operating temperature.

FIGURE 5 is a cross sectional view taken along line 5-5 of FIGURE 4.

FIGURE 6 is an enlarged view, in part similar to FIGURES 2 and 4, illustrating the enrichment device as it appears during power operation before the engine has reached its operating temperature.

FIGURE 7 is a cross sectional view taken along line 77 of FIGURE 6.

Referring now in detail to FIGURE 1, there is indicated generally at 11 a charge forming device embodying this invention. The charge forming device 11 is attached to an intake manifold 12 of an internal combustion engine. A primary mixture passage 13 of the charge forming device 11 is positioned in alignment with a mixture conduit 14 of the intake manifold 12. Formed within the charge forming device 11 is a fuel bowl 15 that is adapted to supply idle and running fuel to the primary induction passage 13 in a known manner as shown by element 13a for example. A throttle valve 16 positioned in the induction passage 13 controls the flow of mixture therethrough. The structure thus far described is conventional.

The charge forming device 11 also includes an auxiliary enrichment mechanism, indicated generally at 17 and shown in more detail in enlarged views 2-7. The auxiliary enrichment mechanism 17 comprises an auxiliary induction passage 18 in communication at its upper end with the atmosphere. The lower end of the auxiliary induction passage 18 communicates with the mixture conduit 14 of intake manifold 12 through the primary induction passage 13 posterior to the throttle valve 16.

A valve member 19 is rotatably journa'led in the charge forming device 11 and has a valve portion 21 that extends across the auxiliary induction passage 18. The valve member 19 has a generally cylindrical configuration, however, the valve portion 21 is relieved to provide a semicylindrical shape (FIGURES 3, 5 and 7). The rotary position of the valve portion 21 controls the air flow through the auxiliary induction passage 18.

Affixed to one end of the valve member 19 is a circular disc 22 that is contained within a cylindrical cavity 23 formed in the body of the charge forming device 11. An outwardly extending projection 24 is secured to the disc 22 adjacent its periphery. One end of a thermally responsive spring 25 encircles the projection 24 and the other end of the thermostatic spring 25 is afiixed to an inwardly extending projection 26 formed on an insulated cover 27 that encloses the cylindrical cavity 23. The thermally responsive spring 25 rotatably positions the valve member 19 in response to temperature variations.

The inner end of the valve member 19 is received in a bore 28 formed in the body of the charge forming device 11. The bore 28 is positioned between induction passages 13 and 18 with its axis intersecting the passages. A fuel conduit 31 interconnects the bore 28 with the fuel bowl 15. An axially extending fuel channel 32 is drilled into the valve member 19 from its inner end and terminates adjacent the inner end of the valve portion 21.

A seat 33 formed at the inner end of the fuel channel 32 cooperates with a needle 34 formed in the body of the charge forming device 11 at the inner end of the bore 28. In addition to being rotatably journaled in the charge forming device 11, the valve member 19 is supported for limited axial movement. In the innermost axial position of the valve member 19, the needle 34 cooperates with the seat 33 to prevent the flow of fuel from the bore 28 into the inner end of the fuel channel 32. A metered orifice 35 is provided, however, to interconnect the bore 28 and the fuel channel 32 when the needle 34 and seat 33 are engaged.

A cold running enrichment orifice 36 extends from the outer end of the fuel channel 32 through the valve member 19 to the valve portion 21. A cranking enrichment orifice 37 extends from the outer end of the fuel channel 32 radially through the valve member 19. A power enrichment orifice 38 also extends raidally from the outer end of the fuel channel 32. The orifices 37 and 38 are axially positioned so that they will be out of registry with the auxiliary induction passage 18 when the valve member 19 is in its innermost axial position (FIGURE 1). These orifices are positioned, however, to be in registry with the auxiliary induction passage 18 when the valve member 19 is at its outermost axial position (FIGURES 2, 4 and 6).

A coil compression spring 39 contained within the bore 28 abuts the inner end of the bore 28 and a shoulder 41 formed on the valve member 19 to urge the valve member 19 to its outermost axial position. The outward movement of the valve member 19 is limited by contact of the disc 22 with the projection 26 (FIGURES 2, 4 and 6).

The disc 22 acts as a pressure responsive member to exert a force that tends to move the valve member 19 to its innermost axial position. Intake manifold vacuum is exerted upon the inner surface of the disc 22 from the auxiliary induction passage 18 through a conduit 42 that connects the auxiliary induction passage 18 and the cylindrical cavity 23. The outer surface of the disc 22 is exposed to atmospheric pressure through a conduit 43. The pressure differential across the disc 22 positions vthe disc axially within the cavity 23 and, accordingly,

axially positions the valve member 19.

There is a small. annular clearance between the external surface of the disc 22 and the internal surface of the cylindrical cavity 23. Because of the clearance an air flow may occur from the cavity 23 into the auxiliary induction passage 18 through the conduit 42. The conduit 43 is connected to an exhaust manifold heat stove (not shown) to provide a source of heat for the thermally responsive spring that is responsive to engine temperature. The heated air that enters the cavity 23 from the heat stove passes around the clearance between the disc 22 and the cavity 23 and enters the auxiliary induction passage 18 through the conduit 42.

Operation When the engine is cold and not running, the cooled thermostatic spring 25 will have rotated the valve member 19 to the position shown in FIGURES 2 and 3. The valve portion 21 is in its wide open position to permit maximum air flow through the auxiliary induction passage 18 into the intake manifold mixture passage 14. During cranking insufficient manifold vacuum is exerted upon the disc 22 to overcome the action of the coil compression spring 39 and the valve member 19 is moved to its outermost axial position (FIGURE 2). The circumferential spacing of the fuel discharge orifices 37 and 38 is such that the cranking enrichment orifice 37 is exposed to the downstream side of the auxiliary induction passage 18. Because the diameter of the valve member 13 is greater than the diameter of the auxiliary induction passage 18, the power discharge orifice 33 is blocked from discharging fuel by the body of the charge forming device 11.

During cranking supplementary fuel is discharged from the fuel bowl 15 through the conduit 31 into the fuel channel 32 of the valve member 19. The seat 33 of the valve member 19 is moved away from the needle 34 by the action of the coiled spring 39 to permit the fuel to be discharged from the cranking enrichment orifice 37. Additional fuel will be discharged through the cold enrichment orifice 36.

When the engine fires and commences to run, the resulting high intake manifold vacuum will be exerted through the mixture conduit 14 into the auxiliary induction passage 13. The decreased pressure in the auxiliary induction passage 18 is transmitted through the conduit 42 to the cavity 23. The pressure differential on the disc 22 causes the disc to be drawn inward and move the valve member 19 to its innermost axial position (FIG- URE l). Heated air is drawn from the exhaust stove through the conduit 43 into the cylindrical cavity 23. A portion of the heated gas may flow through the clearance between the disc 22 and the cavity 23 into the auxiliary induction passage 18 through the conduit 42.

When the valve member 19 is moved to its innermost axial position by the intake manifold vacuum, the coil spring 39 is compressed permitting the needle 34 to engage the seat 33 and preclude the flow of fuel into the fuel cavity 32 through its open end. Fuel may enter the cavity 32, however, through the metered orifice 35. This fuel is discharged through the cold enrichment orifice 36 to provide an enriched mixture to stabilize the cold running operation of the engine and prevent stalling. The additional air and fuel flowing through the auxilary induction passage 18 also increases the idle speed of the engine.

The heated air drawn into the cavity 23 raises the temperature of the thermally responsive spring 25 in response to the engines temperature to cause the valve portion 21 of the valve member 19 to be rotated in a counterclockwise direction. This rotation of the valve member 19 decreases the amount of fuel and air flow through the auxiliary conduit 18 in response to an increase in the temperature of the engine as evidenced by the heat generated by the exhaust manifold stove. FIG- URE 7 illustrates the position of the valve portion 21 when the engine is at a temperature below its normal operating temperature. FIGURE 5 illustrates the position of the valve portion 21 when the engine has reached its normal operating temperature.

The main fuel discharge system in the primary induction conduit is calibrated to provide sufficient fuel for normal running operation. Additional fuel is required by the engine, however, to produce its maximum power output. The enrichment mechanism 17 satisfies the additional fuel requirements in the manner now to be described. An increase in the load upon the engine is evidenced by a decrease in intake manifold vacuum. The resulting intake manifold vacuum is insufficient to overcome the action of the coil spring 39 and the valve member 19 is moved to its outermost axial position (FIG- URE 4). When the engine is warm, the power discharge orifice 38 has been rotated by the action of the thermally responsive spring 25 toward the downstream side of the auxiliary induction passage 18 (FIGURE 5). Because of the circumferential spacing, the cold starting enrichment orifice 37 will be blocked from discharging fuel by the body of the charge forming device 11. The axial movement of the valve member 13 separates the needle 34 from the seat 33 and fuel may flow freely from the fuel bowl 15 through the conduit 31 into the bore 28 and channel 32. The rate of fuel discharge into auxiliary induction passage 18 is determined by the size of the power discharge orifice 38.

Power enrichment is also possible during engine warmup. Before the valve portion 21 has been rotated to its closed position by the thermally responsive spring 25, both the starting enrichment orifice 3-7 and the power enrichment orifice 38 register to some extent with the downstream side of the auxiliary induction passage 18 (FIG- URE 7). When intake manifold "vacuum \falls off indicating a demand for increased power, the coil spring 39 will urge the valve'mernber 1 9 to its axially outward position (FIGURE 6). This opens the inlet to the fuel cavity '32 and places the discharge orifices 37 and '38 in registry with the auxiliary induction passage 18. Neither orifice is in full communication with the auxiliary inducti-on passage '18, however. The orifices 3-7 and 38 will each .partiallydischarge. The combined flow through the orifices 37 and 38 is sufficient to satisfy the increased power requirements of the engine. Again, the circumferen'tial spacing of the orifices 37 and 38 determines the magnitude of flow through each orifice and the time at which the power enrichment orifice 38 comes into full operation. The rate of the coil compression spring 39, .the size of the disc 22 and the clearance b'etweenthe disc 22 and the cavity 23 determine the point at which the intake manifold vacuum will cause the discharge orifices 37 and '38 to move into registry with the auxiliary induction passage #1 8. It 'is further noted that the power orifice 3-8 will normally be of smaller size than the cold starting enrichment orifice '37.

It is to be understood that the invention is not to be limited to the described embodiment, which is exemplary onlyof the preferredformtof the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by-the appended claims.

We claim: "1. A charge forming .device adapted to supply a combustible mixture to the intake manifold of an internal combustion engine comprising a main induction passage having a throttle valve for controlling the flow therethrough, a fuel source, means for discharging fuel from said fuel source into said main induction passage, an auxiliary induction passage in communication with the -intake-manifold,'a valve member journaled in said charge forming device for rotary and axial movement, said valve member having a first portiondisposed in said auxiliary induction passage for controlling the flow therethrough, thermally responsive means for rotatabl-y positioning said first portion to control the flow through said auxiliary induction passage, asupplementary fuel discharge means in communication with said fuel source for discharging supplementary fuel into one of said induction passages, pressure responsive means in communication with the intake manifold for axially positioning said valve member in response to changes in intake manifold vacuum, and fuel valve means for controlling the discharge of supplementary fuel, said fuel valve means being positioned by the axial position of said valve member.

2. A charge forming device adapted to supply a combustible mixture to the intake manifold of an internal combustion engine comprising a main induction passage having a throttle valve for controlling the flow therethrough, a fuel source, means for discharging fuel from said fuel source into said main induction passage, an auxiliary induction passage in communication with the intake manifold, a valve member journaled in said charge forming device for rotary and axial movement, said valve member having a first portion disposed in said auxiliary induction passage for controlling the flow therethrough, thermally responsive means for rotatably positioning said valve member to control the flow through said auxiliary induction passage, a supplementary fuel discharge means in communication with said fuel source for discharging supplementary fuel into one of said induction passages, said valve member having a second portion for controlling the rate of fuel discharge from said supplementary fuel discharge means in response to the rotary position of said valve member, means for stopping the supplementary fuel discharge upon movement of said valve member in a first axial direction, and pressure responsive means in communication with said intake manifold for axially positioning said valve member in response to changes in intake manifold vacuum.

3. A charge forming device adapted to discharge a combustible mixture into the intake manifold of an internal combustion engine comprising an induction passage in communication with the intake manifold, a fuel discharge member journ-aled in said charge forming device for rotary and axial movement, first and second circum-ferentially spaced fuel discharge orifices formed in said fuel discharge member, said-discharge orifices being axially positioned to register with said induction passage upon movement of said fuel discharge member into a first axial position, thermally responsive means operatively connected to said fuel discharge member for rotatably positioning said fuel discharge member, and pressure responsive means for axially positioning said fuel discharge member, said pressure responsive means being in communication with the intake manifold for axially moving said fuel discharge member into its first axial position when intake manifold vacuum is low.

4. A charge forming device adapted to discharge a combustible mixture into the intake manifold of an internal combustion engine comprising an induction passage in communication with the intake manifold, a fuel source, a fuel discharge member journaled insaid charge forming device for rotary movement about an axis that intersects said induction passage, said fuel discharge member further being axially movable between first and second axial positions, an axially extending fuel channel formed in said fuel discharge member, one end of said fuel channel being in communication with said fuel source, first and second circumferentially spaced discharge orifices in said fuel discharge member extending from the other end of said fuel channel radially outward through said fuel discharge member, said orifices being axially positioned to register with said induction passage when said fuel discharge member is in its first axial position and being out of registry with said induction passage when said fuel discharge member is in its second axial position, and pressure responsive means in communication with said intake manifold for axially positioning said fuel discharge member, the circumferential spacing of said orifices being effective to dispose the first discharge orifice for discharge downstream into said induction passage in a first rotary position of said fuel discharge member and to dispose the second discharge orifice for discharge downstream into said induction passage in a second rotary position of said fuel discharge member, and thermally responsive means for rotating said fuel discharge member between its first and second rotary positions in response to temperature changes.

5. A charge forming device adapted to supply a combustible mixture to the intake manifold of an internal combustion engine comprising a main induction passage and a throttle valve for controlling the flow therethrough, a fuel source, means for discharging the fuel from said fuel source into said main induction passage, an auxiliary induction passage in communication with the intake manifold, a valve member rotatably supported in said charge forming device and having a valve portion extending into said induction passage for controlling the air flow therethrough, thermally responsive means for rotatably positioning said valve member, said valve member further being axially movable in said charge forming device between first and second axial positions, an axially extending fuel channel formed in said valve member and having one end in communication with said fuel source, a fuel discharge orifice extending from the other end of said fuel channel radially outward through said fuel discharge member contiguous to said valve portion, said fuel discharge orifice being axially positioned to register with said auxiliary induction passage when said valve member is in its first axial position and to be out of registry with said auxiliary induction passage when said valve member is in its second axial position, biassing means urging said valve member toward its first axial position, and pressure responsive means in communication with the intake manifold for urging said valve member toward its second axial position in response to an increase in intake manifold vacuum.

6. A charge forming device adapted to supply a combustible mixture to the intake manifold of an internal combustion engine comprising a main induction passage having a throttle valve for controlling the flow therethrough, a fuel source, means for discharging the fuel from said fuel source into said main induction passage, an auxiliary induction passage in communication with the intake manifold, a valve member rotatably supported in said charge forming device and having a valve portion extending into said induction passage for controlling the air flow t'herethrough, thermally responsive means for rotatably positioning said valve member, said valve member further being axially movable in said charge forming device between first and second axial positions, an axially extending fuel channel formed in said valve member and having one end in communication with said fuel source, a first discharge orifice extending from the other end of said fuel channel through said valve member and terminating in said valve portion for providing cold running fuel enrichment, a second discharge orifice extending from said other end of said fuel channel radially outward through said fuel discharge member for providing cold starting fuel enrichment, said second orifice being axially positioned to register with said induction passage when said valve member is in its first axialposition and to be out of registry with said auxiliary induction passage when said valve member is in its second axial position, biassing means urging said valve member toward its first axial position, and pressure responsive means in communication with said intake manifold for urging said valve member toward its second axial position upon an increase in intake manifold vacuum.

7. A charge forming device adapted to supply a combustible mixture to the intake manifold of an internal combustion engine comprising a main induction passage having a throttle valve for controlling the flow therethrough, a fuel source, means for discharging fuel from said fuel source to said main induction passage, an auxiliary induction passage in communication with the intake manifold, a valve member rotatably supported in said charge forming device and having a valve portion extending into said induction passage for controlling the air flow therethrough, thermally responsive means for rotata bly positioning said valve member, said valve member further being axially movable in said charge forming device between first and second axial positions, an axially extending fuel channel formed in said valve member and having one end in communication with said fuel source, a first discharge orifice extending from the other end of said fuel channel through said valve member and terminating in said valve portion for providing cold running mixture enrichment, second and third discharge orifices extending from the other end of said fuel channel radially outward through said valve members, said second and third discharge orifices being axially positioned to register with said auxiliary induction passage when said valve member is in its first axial position and to be out of registry with said auxiliary induction passage when said valve member is in its second axial position, said second and third discharge orifices being circumferentially spaced, the circumferential spacing of said orifices being effective to dispose said second discharge orifice for discharge downstream into said auxiliary induction passage in a first rotary position of said valve member and to dispose said third discharge orifice for discharge downstream into said induction passage in a second rotary position of said valve member, biassing means urging said valve member toward its first axial position, and pressure responsive means in communication with said intake manifold for urging said valve member toward its second axial position when intake manifold vacuum is high.

References Cited by the Examiner UNITED STATES PATENTS 1,477,280 12/1923 Pordes 261 -44 1,520,926 12/1924 Brown 261--44 1,861,725 6/1932 Stokes 123124 1,904,936 4/ 1933 Stokes 123-124 2,074,471 3/ 1937 Holley et al. 26'1-39 2,145,230 1/1939 Arrighi 123124 2,225,261 12/ 1940 Jorgensen 123-1 19 2,598,450 5/1952 Shaft 12. 119 2,617,633 11/1952 Udale 261-44 2,621,911 12/ 1952 Lindsteadt.

2,940,436 6/ 1960 De Clair et al. 261-69 2,949,102 8/1960 Arkus-Duntov 123-1 19 2,969,965 1/1961 Braun 26169 X 2,986,380 5/1961 Read 261--39 3,149,184 9/1964 Szwargulski 261-69 X HARRY B. THORNTON, Primary Examiner.

T. R. MILES, Assistant Examiner.

Claims (1)

1. A CHARGE FORMING DEVICE ADAPTED TO SUPPLY A COMBUSTIBLE MIXTURE TO THE INTAKE MANIFOLD OF AN INTERNAL COMBUSTION ENGINE COMPRISING A MAIN INDUCTION PASSAGE HAVING A THROTTLE VALVE FOR CONTROLLING THE FLOW THERETHROUGH, A FUEL SOURCE, MEANS FOR DISCHARGING FUEL FROM SAID FUEL SOURCE INTO SAID MAIN INDUCTION PASSAGE, AN AUXILIARY INDUCTION PASSAGE IN COMMUNICATION WITH THE INTAKE MANIFOLD, A VALVE MEMBER JOURNALED IN SAID CHARGE FORMING DEVICE FOR ROTARY AND AXIAL MOVEMENT, SAID VALVE MEMBER HAVING A FIRST PORTION DISPOSED IN SAID AUXILIARY INDUCTION PASSAGE FOR CONTROLLING THE FLOW THERETHROUGH, THERMALLY RESPONSIVE MEANS FOR ROTATABLY POSITIONING SAID FIRST PORTION TO CONTROL THE FLOW THROUGH SAID AUXILIARY INDUCTION PASSAGE, A SUPPLEMENTARY FUEL DISCHARGE MEANS IN COMMUNICATION WITH SAID FUEL SOURCE FOR DISCHARGING SUPPLEMENTARY FUEL INTO ONE OF SAID INDUCTION PASSAGES, PRESSURE RESPONSIVE MEANS IN COMMUNICATION WITH THE INTAKE MANIFOLD FOR AXIALLY POSITIONING SAID VALVE MEMBER IN RESPONSE TO CHANGES IN INTAKE MANIFOLD VACUUM, AND FUEL VALVE MEANS FOR CONTROLLING THE DISCHARGE OF SUPPLEMENTARY FUEL, SAID FUEL VALVE MEANS BEING POSITIONED BY THE AXIAL POSITION OF SAID VALVE MEMBER.

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