US2670761A - Control valve for fuel systems - Google Patents

Description

March 2, 1954 FEGEL 2,670,761

CONTROL VALVE FOR FUEL SYSTEMS Filed Aug. 29. 1949 ////4V%////2 3 E 34 go Patented Mar. 2, 1954 UNITED STATES PATENT OFFICE CONTROL VALVE FOR FUEL SYSTEMS Albert Fegel, Whittier, Calif. Application August 29, 1949, Serial No. 112,966

2 Claims. 1

This invention relates generally to fuel supply systems for internal combustion engines and refers more particularly to valve assemblies of the type employed to control the power jet in the carburetor of a fuel supply system.

In certain types of fuel supply systems it is customary to control the flow of fuel through the power jet of the carburetor with a vacuum operated valve assembly commonly known to the trade as an economizer valve. Valves of this general type are ordinarily urged by a spring to a position wherein communication through the power jet is open, and are closed against the action of the spring by a diaphragm in response to the vacuum existing in the intakemanifold of the engine. The arrangement is such that when the engine is being operated at constant speed or part throttle the vacuum in the intake manifold is sufficient to draw the diaphragm to a position wherein the power jet is closed. However, when the throttle valve is suddenly opened, for example, the intake manifold vacuum decreases sufiiciently to enable the spring to open the valve and thereby supply the required additional amount of fuel through the power jet into the carburetor mixing chamber.

The above principle of operation has been found highly satisfactory in obtaining economical operation without sacrificing engine performance. However, the particular economizer valves used in the past for the above purpose have not been entirely satisfactory. The design of these valves materially complicates assembly of the various parts involved and in addition results in an unstable unit which has the effect of reducing the performance efiiciency of the fuel system.

With the above in view, it is an object of this invention to provide an economizer valve composed of a relatively few simple parts capable of being inexpensively manufactured, assembled and installed in a fuel supply system or carburetor.

It is another object of this invention to provide an economizer valve assembly wherein the valve plunger has a sliding bearing contact of substantial length with the surrounding supporting casing to thereby avoid any possibility of lateral displacement of theplunger during operation and at the same time affords free passage of fuel through the casing along the plunger.

The manner in which the design of the econo-' mizer valve forming'the subject matter of this invention facilitates assembly and promotes stability will be apparent from the following de- 2 scription, especially when considered in connection with the accompanying drawing wherein:

Figure 1 is. a diagrammatic sectional view showing a part of a carburetor equipped with an economizer valve forming the subject matter of this invention.

Figure 2 is a vertical sectional view through the valve. 1 a

Figure 3 is a cross-sectional view taken on the line 33 of Figure 2; and

Figure 4 is a plan view of the valve shown in Figure 2.

In order to simplify the disclosure, only those parts of the carburetor having a bearing on the operation of the economizer valve are diagrammatically illustrated. With this in view, reference is made to Figure l. of the drawing, wherein the numeral lll designates a carburetor having a fuel supply chamber l and having an additional chamber l2 in which fuel from the supply chamber l l is mixed with air to provide a combustible mixture of gases. The chamber I2 is connected to the intake manifold (not shown) of an internal combustion engine, and in accordance with conventional practice the flow of fuel mixture through the chamber l2 to the intake manifold is controlled by a throttle valve l3 suitably pivotally supported within the mixing chamber.

The fuel from the supply chamber l l is metered to the mixing chamber through suitable jets, and in certain designs of carburetors provision is made to supplement the quantity of fuel admitted to the mixing chamber l2 when the throttle approaches wide-open position to increase the engine power. This feature is commonly known to the trade as a power fuel system. and embodies a valve controlled passage P between th fuel supply chamber II and the mixing chamber I2.

The valve assembly controlling communication through the passage P is commonly known as an economizer valve and is indicated generally in the several figures of the drawing by the numeral M. In detail, the valve assembly M comprises a casing l5, a plunger l5 slidably supported by the casing l5 and a diaphragm I! for operating the plunger. The casing l5 has a tubular body part l8 externally threaded at the end It for attachment to the carburetor and has an annular enlargement 20 at the opposite end 2|. As shown particularly in Figure 2 of the drawing, the casing l 5 is formed with a central bore 22 having a portion 23 at the end [9 of the casing reduced in diameter and opening through the end '19 of the casing. A valve seat 24 in the form of an annular flange projects from the end 19 of the casing in concentric relation to the reduced portion 23 of the bore 22. It will also be noted from Figure 2 of the drawing that a flange 25 projects outwardly from the periphery of the enlargement and provides a circular recess 26 at the end 2| of the body part |8. Referring now to Figure 4 of the drawing, it will be noted that the exterior surface of the flange isformed with a plurality of flats 2'|"to enable effectively engaging the enlargement with a suitable wrench or tool for securing the casing in place on the carburetor.

The plunger I6 is shown in Figure 2 of the drawing as having reduced portions 28 and 29 at opposite ends. The reduced end portion 28 extends axially through the reduced portion 23 of the bore 29 and has an external diameter substantially less than the internal diameter of the reduced portion 23 to provide an annular fuel passage 30. A valve member 3| is secured to the reduced portion 28 of the plunger and assumes a position outwardly upon th end |9 of the body part IS. The end of the valve member 3| adja :cent the body part |8is formed'with a recess 32 whichsurrounds the reduced end 28' and serves'to retain a resilient ring 33 in place on the valve member. I The ring 33 is formed of a resilient material which is impervious to the fuel, such for example as synthetic rubber, and is adapted to engage the annular valve seat 24 to close the ann larpassagew.

The reduced end 29 of the valve plunger projects into the recess 26and extends through a central opening formed in the diaphragm H. The diaphragm ll comprises juxtapositioned sheets of flexible material, and the central portion is clamped to the reduced end 29 between a pair of washers 34 and 35. The washer 34 abuts the annular shoulder 36 formed on the plunger by the reduced portion 29, and the washer is clamped in place by peening the extremity of the reduced portion 29 over the outer surface of the washer 35 in the manner indicated by the numeral 31 in Figure 2 of the drawings.'

The periphery of the diaphragm I1 is clamped to the base of the recess .26 adjacent the annular flange 25 by a plate 38 having an outwardly bowed central portion 39 and having an annular clamping portion 40 at the periphery positioned in engagement with the outer edge of the diaphragm. Theplate 3B is clamped in place against the diaphragm I! by crimping the outer edge of the flange '25 over the outer, surface of the annular portion 40 on the plate in the manner, indicated bythe numeral 4| in Figure 2 of the drawing. It follows from the above that the central portion of the diaphragm is effectively clamped to the plunger 15 and the peripheryof the diaphragm is flrmly clamped to the enlargement l9 at the end 2| jef the body part IS.

A bore 42 extends axially of the plunger and is closed adjacent the reduced end 28. The opposite end of the bore 42 is open, and a coil spring 43 is positioned in the bore 42. One end of the -coil=spring abuts the closed end of the bore and the other end of the coil spring engages an adjusting screw 45. The adjusting screw 45 is threadably supported by the central portion of the plate 38 and is adjustable to vary the degree of'zcompression of the spring 43. Inasmuch as one end of 'the spring engages the plunger-and -th e*other end of the spring engages the adjusting screw 45 carried by the casing |5, it follows that the spring normally urges the plunger to the position-shown' iii-Figure 2 of the drawing, wherein 4 the valve member 3| is in its open position with respect to the annular passage 30.

The body portion of the plunger between the two reduced portions 28 and 29 is polygonally shaped in cross-section, as shown in Figure 3 of the drawing. The corner portions, or in other words, the points of intersection of adjacent sides 45 of the plunger are rounded as at 41 and have a sliding contact with the inner surface of the bore 22. "This, construction not only provides clearance spaces 48 of substantial area in the bore 20 but in addition slidably supports the plunger I 6 throughout substantially the full length of the body portion thereof. This is highly desirable irrthat it prevents any possibility of the plunger from shifting laterally relativ to the casing during operation and assures effective performance of the valve over long periods of use. The clearance spaces 48 communicate with the annular intake passage 39 and with radially extending ports 49 formed in the body part l8 adja'ce'nt the'enlargement 29. Since the clearance spaces 48 are of substantial cross-section area due to the shape of the plunger, it Will be understood that free, unobstructed flow of fuel is provided between the passage 30 and the ports 49.

It has previously been stated that the central portions of the diaphragm H is secured to the plunger i6 and the peripheral portion is clamped to the body part |8'of the casing l5. This diaphragm cooperates with the plate 38 to form a chamber 59 and the portion 39 of the plate has openings 5| providing access to the interior of the chamber 50. As will be presently described, the openings 5| communicate with the intake manifold so that the pressure within the chamber 59 corresponds to the manifold pressure. When the vacuum in the intake manifold is relatively high, the valve 3| is held by the diaphragm l! in engagement with the seat 24 to close the passage 30. However, when the vacuum in the intake manifold decreases by sudden opening ofthe throttle valve l3, for example, the spring 43 collapses the diaphragm l1 and moves the valve member 3| away from the seat 24.

In the present instance the economizer valve assembly M is shown as installed with the pasage 39 in communication with the supply chamber H in the carburetor, as indicated diagrammatically in Figure 1 of the drawing. It will also be noted from Figure 1 that the portions 49 communicate with an annular chamber 52 in the carburetor, and this chamber is connected .to the interior of the mixing chamber 2 by a power jet. 53. The openings 5| through the plate 38 communicate with the chamber 54 in the. carburetor, and this chamber is connected to the manifold of the internal combustion engine by the passage P. V

It follows from the above that when the valve 3| is in its open position fuel from the supply chamber flows downwardly through the annular passage 39 and through the clearance space 48 to therports 49. :From the ports 49 the fuel enters the annular chamber 52 and is discharged into the mixing chamber l2 through the power jet 53. As the fuel is dischargedthrough the jet 53 it is broken up into minute particles-so that it will mix more readily withthe air in the mixing chamberv t2. The abovecondition exists only in instances when the vacuum in the manifold or chamber50'is suddenly decreased-by fully or'substantially fully opening the throttle valve |3 andv supplies the additional,fuel required for the increased, power demand; During normal operation of the engine the vacuum in the chamber 50 is sufiicient to counteract the spring 43 and thereby hold the valve member 3| against the seat 2 3.

It will be noted from the design of the economizer valve that the several parts of this valve may be readily assembled. One of the first steps in the assembly is to sleeve the central portion of the diaphragm I? and associated washers 3 3, 35 on the reduced end 29 of the plunger. This end is then peened over the washer 35 as indicated by the numeral 31 in Figure 2 of the drawing. The plunger It may then be readily inserted into the bore 28 in the body part l8 of the casing, and as a result of this operation the diaphragm i! assumes its desired position within the recess 26. The plate 38 is then sleeved into the recess 25 and the outer extremity of the flange 25 is crimped over the peripheral portion 40 of the plate 38 in the manner indicated by the numeral 41 to clamp the diaphragm in place. Upon completion of this operation the spring is inserted into the bore t2 through the open end of the latter and the adjusting screw 45 is assembled on the plate 38. The valve member 3| is then secured to the reduced end 28 of the plunger in a manner such that the resilient ring 33 occupies a position adjacent the annular seat 24.

In view of the above, it will be understood that I have provided a relatively simple, compact economizer valve which lends itself to easy as-- sembly and assures effectively supporting the sliding plunger against lateral displacement. In addition it will be noted that the resilient seating ring 33 assures a tight seal with the annular valve seat 2 in the closed position of the valve, regardless of irregularities in manufacture, and even though some dirt or foreign matter accumulates on the seat.

What I claim as my invention is:

1. A pressure responsive valve structure comprising a body having an elongated bore terminating at one end in a valve seat surrounding said bore and terminating at its other end in a laterally enlarged recess, a valve movable toward and away from said valve seat and including an elongated portion slidable in said bore and shaped to define a longitudinally extending fluid passage therewith and an end portion located in said recess, said valve having a longitudinal bore opening at the end thereof in said recess and having a closed inner end, a diaphragm in said recess connecting said valve to said body, a spring in the bore of said valve having one end seated at the closed inner end of the bore in said valve, an apertured closure plate covering said recess and defining a diaphragm chamber therewith, a screw carried by said plate, said screw having an end portion received in the end of the bore in said valve engaging the other end of said spring therein and slidably engaging said valve to guide the same for longitudinal movement in the elongated bore of said body.

2. Pressure responsive valve structure comprising an elongated body having a passage extending therethrough, an outwardly facing valve seat at one end of said body surrounding said passage, the opposite end of said body being laterally enlarged and provided with a laterally en larged outwardly facing recess including a longitudinally extending peripheral flange, an elongated member slidable in said passage and shaped to define a longitudinally extending fluid passage therewith, said member inciuding a first end portion extending beyond said one end of said body, a valve on said first portion cooperable with said valve seat, said member having a secone. end portion extending beyond the end of said passage at the other end of said body and located within said recess, a flexible diaphragm said recess having its periphery connected to said flange and its central portion connected to the end of said member within said recess, a plate having its periphery located within said recess and clampingly engaging the periphery of said diaphragm, said plate having an opening there hrough, said member having an elongated recess extending therein from the end of said member located Within said laterally enlarged recess, a spring received in said elongated recess, said plate having a threaded aperture, a screw in said aperture having a reduced portion slidably received in the open end of said elongated recess bearing against the end of said spring and providing a guide for longitudinal movement of said member.

ALBERT FEGEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 583,546 Pierson June 1, 1897 1,889,503 Thomas Nov. 29, 1932 2,035,636 Chandler Mar. 31, 1936 2,136,163 White Nov. 8, 1938 2,157,551 Loebs May 9, 1939 2,212,486 Zoder Aug. 20, 1940 2,341,758 Carpenter Feb. 15, 1944

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