US2399459A - Automatic fuel feed control for internal-combustion engines - Google Patents

Description

April 30, 1946. 5 J BOUCHEZ 2,399,459

AUTOMATIC FUEL FEED CONTROL FOR INTERNAL-COMBUSTION ENGINES Filed July 24, 1942 2 Sheets-Sheet 1 April 1946. 5. J. BOUCHEZ 2,399,459

COMBUSTION ENGINES AUTOMATIC FUEL FEED CONTROL FOR INTERNAL Filed July 24, 1942 2 Sheets-Sheet 2 III;

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@hlo, aselgmor to The en liiollerng wompanvp than ton, dildo, a corporation of male Application .linly at, i942. serial in. stance This invention relates to fuel supply systems for internal combustion engine of the compression ignition type wherein the quantity of fuel de livered to the engine by the fuel pump is controlled automatically by a governor in the form of a spring-pressed diaphragm that is responsive to the variation of the vacuum in the air induction pipe of the engine at different engine speeds in diflierent position of adjustment of a throttle valve located in a Venturi air inlet in said pipe.

The principal objects oi. the present invention are to provide a vacuum speed governor system that will shorten the range of revolutions per minute or running speed of the engine between no load and full load in all positions of adjustment of the throttle valve from low or idling speed to high speed, thereby giving the vacuum governor the desired characteristics of a mechanical governor, to provide'for adjusting such speed range to accommodate specific conditions, and to provide for simplicity and cheapness of construction and compactness of design.

The invention consists in Providing the vacuum I governing system with an auxiliary diaphragm adapted, when the main governor is moving in the direction of decreased fuel feed as a result of increased manifold vacuum due to increased ongine speed, to close the throttle valve and thus further increase the manifold vacuum thereby accelerating the movement of the main governor towards fuel cut-oil? position and thus shortening the period between full load and no load in terms of speed; the invention also consists in providing for initially adjusting the auxiliary diaphragm relative to the throttle valve to cause the latter to start its closing movement at the desired manifold vacuum; and it also consists in the construction, combinations and arrangements of parts hereinafter described and claimed. a

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. l is a side elevational view, showing the air inlet manifold and fuel injection pump of a compression ignition engine provided with a vacuum fuel feed control embodying my invention,

Fig. 2 is an enlarged central horizontal section through the vacuum governor for operating the fuel feed control member of the pump,

Fig. 3 is a plan view of the air inlet fitting which contains the venturi, throttle valve and the auxiliary governor for actuating the latter,

Fig. 4 is a side view of said inlet fitting,

' Fig. 5 is a horizontal section on the line 5-5 in- Fig. 4.

i (oi. isle-icon Fig, 6 ice. vertical section on the line t-t in F Fig. 7 is a vertical section on the line ii-l in Fig. 6,

Fig. 8 is a fragmentary section on the line o-s.

in Fig. 5; and

Fig. 9 is a diagr illustrating in inches of mercury the manifold vacuum between iull load and no load, and the speed of the engine in revolutions per minute at low or idling and lull throttle manifold A of a multicylinder internal combiistion engine of the Diesel type, and a multicylinder fuel injection pump B having a horizontally reciprocable fuel control member or rod 0 ins regulating the volume of fuel supplied said pump to the respective cylinders of said engine. type of variable delivery iueliniection pump is well known and it is considered ecessary to illustrate it in detail.

The fuel feed control red C of the pump B is actuated to vary the quantity oi the iuei charges by means of a governor D that is responsive to the variation of the vacuum in the air intake manifold A of the engine. The vacuum governor D comprises a housing i that is mounted on one end of the fuel injection pump B and is provided with an expanding and contracting chamber 2, the inner wall of which is formed by a piston or die:- phragm 3 comprising a metal disk d that is connected at its peripheral edge to the wall of the governor housing by means oi a fluid-tight accordion or bellows like member 5 of flexible material that permits endwise movement oi said disk endwise of said governor housing and thus increases or decreases the volumetric content of said chamber.

A relatively light compression coil spring 8 is interposed between the diaphragm 4i and the outer end of the governor housing i and tends to force said diaphragm towards the pump housing B and thus increase the volume of the governor chamher 2. A relative heavy spring I is mounted in a sleeve 8 that is threaded through the outer end wall of the governor housing i in axial alinemeat but normallyout of contact with the diaphragm 3. As shown in Fig. 2, the control or rack rod C of the pump B extends into the governor g housing i and is connected by a screw 9 to a a suitable air cleaner (not shown).

is a horizontal rock shaft 62, one end of which extends outside of said housing and is provided with an operating arm l3. Located in the space between the inner wall of the governor housing and the diaphragm therein is a lever l4 that is fixed to the rock shaft and has two upwardly extending arms l5 and I6, respectively. The arm 65 is adapted to bear against the bracket II] that connects the diaphragm to the rack rod C.of the pump B; the other arm 16 isadapted to bear against an adjustable stopescrew ll that is threaded through the inner end wall of the gov ernor housing in abutting relation to said other arm.

The vacuum chamber 2 of the governor D communicates with the air inlet manifold A of the engine through a suitable pipe or conduit Ill and an air inlet fitting E that is rigidly secured to the front face of said manifold, preferably by bolts it. The inlet fitting E comprises a housing 2% having an inlet passageway 2i extending downwardly'therethrough and opening laterally at its lower end into a registering opening in the front wall of the manifold A, said fitting being provided at the upper end of said passageway with a threaded ring or spider 22 adapted to support A Venturi sleeve or tube 24 is mounted in the upper end 'portion of the inlet passageway 2! above the lower laterally extending outlet or discharge end thereof.

The suction pipe l8 leading from the engine manifold A to the vacuum chamber 2 of the governor D is connected by means of a nut 25 to the outer end of a nipple or hollow stud 26, which is threaded into a radial bore provided therefor in the inlet fitting E and extends through the Venturi sleeve 24 and opens into the bore thereof. Mounted in the inner end of the hollow stud 26 is a ball check valve 23 which opens in thedirection of the venturi 24 against the pressure of a valve closing spring 23a. Located in the venturi 24 at the constriction therein is a butterfly or throttle valve 21 that is fixed to a horizontal shaft 28 that extend through registering diametral bores provided therefor in the air inlet fitting E and said venturi at right angles to the nipple 28 just above the level thereof. The valve shaft 28 is joumaled in suitable leakproof bearings 29 provided therefor in the inlet fitting E and extends into a vacuum chamber 30 formed therein at one side of the inlet passageway 2| where it is provided with a clamped-on arm 3|.

The arm 3| of the throttle valve shaft 28 is connected by a link 32 with the lower arm of a rock lever 33 that is pivotally supported intermediate between its ends on a horizontal pivot stud 34 fixed to the lower end of a supporting link 35 whose upper end is pivotally secured, as at 33, to a bracket 3'! fixed to the casing or housing 38 of an auxiliary vacuum governor F located in the vacuum chamber and has a diaphragm 33 forming a movable wall thereof. As shown in the drawings; the governor casing 38 fits in an opening provided therefor in the wall of the vacuum chamber 30 and is held in place in said opening by a leak-proof connection including the clamping ring 4!], screw 4| and gasket 42. J ournaled in a suitable leakproof bearing 43 provided therefor in the outer side wall of the vacuum chamber 30 of the inlet fitting E is a horizontally disposed throttle shaft 44 that is disposed parallel with the throttle valve shaft 28 between the latter and the auxiliary governor F. The exposed outer end of the throttle shaft 84 has an operating arm 45 fixed thereto; and said shaft extends into the vacuum chamber 30 and has a crank arm 46 fixed thereto that terminates at its free end in a cranl: pin 46a which has a bearing in the upper arm of the rock lever 33. The pivot or fulcrum pin 34 for the rock lever is connected to the vacuum chamber opposing side of the diaphragm 34 of the auxiliary governor F centrally thereof by a link 4?.

The outer end of the casing 38 of the auxiliary governor F has an axially projecting tubular extension 43 that is threaded internally to receive one end of an exteriorly threaded nipple or tubular stud 49, whose other or outer end has a cap 49a threaded thereon. Extending into the outer end portion of the bore of the nipple til is a threaded stud 50 having a nut 56 threaded thereon that seats against the outer end of said nipple and has an inwardly extending pilot portion 5hr fitting in the outer end thereof. The stud 53 is also provided at its outer end with a lock nut 52 adapted to abut against the outer end of the nut ill. The threaded stud 53 has a diametral slot 58a in the outer end thereof whereby the stud may be adjusted axially of the nuts [55, 52 by means of a screwdriver. The diaphragm 33 has a stud 53 projecting axially from the outer end face thereof into the inner end of the nipple 49. The adjustable stud lit in the outer end of the nipple 49 and the diaphragm stud 53 are connected by a coil tension spring at having curved end portions that hook into opening provided therefor in the adjacent ends of the respective studs. The diaphragm stud 53 has an enlarged base flange 53a that is normally held in abutting relation to the inner end of the nipple by means of the tension spring 54. The space orchamber 55 between the outer end face of 40 the diaphragm 39 and the casing or housing 38 of the auxiliary governor F is open to the atmosphere through a series of holes 56 that extend radially through the axial nipple supporting extension 48 of said casing.

Communication is established between the intake manifold A and the vacuum chamber 30 to render the diaphragm 39 of the auxiliary governor therein responsive to the vacuum in said manifold by means of a series of openings 51v that extend radially through the nipple 26 outwardly of the check valve 23 therein and open into an annular chamber 58 which surrounds said nipple and opens through a radial passageway 59 into said vacuum chamber. I

By the arrangement described, the throttle valve 21 is adjusted in the venturi 24 in the air inlet fitting E of the intake manifold A to obtain the desired engine speed by turning the operating arm 45 on the exposed outer end of the throttle shaft 44, thereby rotating said shaft and causing the crank pin 46a on the crank arm 46 thereof to rotate the rock lever 33 on its supporting pivot 34 and transmit rotary motion to the shaft 28 of the throttle valve 21 through the link connection 32 between the rock arm 3| on the throttle valve shaft and the lower arm of said rock lever. Low speed or no throttle and high speed or full throttle positions of the throttle valve 21 are established by means of a pair of adjustable stopsin the form of a pair of screws 60 that are disposed one on each side of the throttle shaft 44 and are threaded through outstanding lugs 6| provided therefor on the adjacent wall of the inlet fitting E and are provided with lock nuts 62. When the arm 45 on the throttle shaft 44 is in contact with one of the neonate said valve is in nearly closed, idling, low speed or no throttle position.

During operation of the device in any position of adjustment oi the throttle valve ill, the check valve it is held open by the vacuum or suction generated in the air intalre'passageway t l, thereby placing said passageway in continuous communication with the vacuum chamber t of the main governor D. Thus, an increase in' engine speed causes an increase in vacuum in the intake manifold a and this increased vacuum causes the diaphragm t oi the main governor D to move against the pressure of the spring 8 and thus shift the fuel feed control member (3 of the fuel pump B in the direction of decreased fuel supply and thus reduce the speed of the engine. When the speed of the engine decreases. there is a corresponding decrease in the manifold vacuum, whereupon the i fuel feed control member C is shifted by the diaphragm spring 6 of the main governor in the direction of. increased fuel feed, thereby increasing the speed of the engine. 1

When, due to the increased speed of the en gine,- the manifold vacuum rises to a predetermined point, the diaphragm 39 of the auxiliary governor F is actuated by the increased vacuum against the tension of the spring 54, thus causing the supporting pivot 84 for the rock lever 33 to move inwardly about the stationary throttle shaft crank pin 4641 as a center, and thereby moving the throttle valve 28 toward idling or slow speed position. This brings about afurther increase in manifold vacuum and thus causes a more rapid movement of the fuel feed control member 0 of the pump D in the direction of decreased fuel s pp y.

In the diagram shown in Fig. 9, the horizontal lines indicate the manifold vacuum from 0 to .95 inch of mercury, the lines marked .80 and .95 indicating the useful throttle range, that is. range in manifold depression in changing from no load or throttle to full load or throttle; the numbers at the base or zero line of said diagram indicate in revolutions per minute the speed of the engine shaft. At .80 inch of mercury vacuum, the vacuum in the vacuumchamber 2 of the pump governor D just balances the spring pressure which holds the fuel feed control member C of the fuel pump in the position of maximum fuel feed. Thus any vacuum below the .80 inch of mercury will cause the engine to operate at full throttle. At .95 inch of mercury vacuum the main spring 6 of the pump governor is fully compressed so that the fuel control rod C of the pump is held 'in low or idling speedposition, that is, the position of minimum fuel delivery. The curved line 63 in the diagram represents the vacuum curve in the idling or low speed throttle position of the throttle valve 21; and the curved line 64 represents the vacuum curve in the high speed throttle position of said valve. The dotted extensions 63a and Na of the two vacuum curves 63 and 64, re-

spectively, represent the vacuum curves of between .85 and .95 inch of manifold vacuum when the throttle valve governor F is not employed.

The actuating spring 54 for the diaphragm 39 of the auxiliary governor F is adjusted by means of the threaded stud so that said diaphragm will start to deflect when the vacuum generated by the venturi 24 reaches about .85 inch of meroury. If the vacuum increases, the spring 54 will be extended and move the pivot point 84 of the J as root: lever lit inwardly; and, as the crank pin the remainsstationary, this inward movement of rocls lever pivot operates through the link 32 to close the throttle valve til, thereby increasing the manifold vacuum and shifting the vacuum curve away from the theoretical curve shown in dotted lines in the diagram. This closing movement of the throttle valve starts at about .85 inch of mercury vacuum; and the probable slope of this vacuum curve is shown in the diagram both at idle or low speed throttle and high speed throttle. As shown in the diagram, full throttle is obtained at idle or low speed throttle about 400 revolutions per minute and, if no throttle valve governor is used, no throttle would be reached at about 4&0 revolutions per minute. When, however, the throttle valve governor F is employed and is adjusted'to operate at .85 inch of mercury vacuum, no throttle will be reached at about 420 revolutions per minute. Athigh speed throttle, the full load speed extends up to about 2500v revolutions per minute and without the auxiliary governor F, no throttle would be reached at about 2800 revolutions per minute;.

throttle to no throttle in all positions of adjustment of the throttle valve. The speeds indicated on the diagram are arbitrary and are intended only to illustrate the action of the auxiliary governor, .85 inch of mercury vacuum being an arbitrary figure which could be brought down to about ,80 inch of mercury vacuum, or full throttle,

depending on the friction of the mechanism, without reducing the full load top speed.

As shown in Fig. 7, the air inlet fitting E of the intake manifold has an auxiliary air inlet opening 65 formed therein below the level of the venturi 24 and in line with the. inlet opening of said manifold. As shown in Fig. 7 of the accompanying drawings, the auxiliary air inlet opening 65 is located in the front face of the air inlet fitting E just below the vacuum chamber 39 therein and is shaped in the form of a venturi. The inlet fitting E has a passageway 68 therein leading from the throat of the air inlet opening 65 to the vacuum chamber 3|]; and said opening is normally closed by means of a threaded plug 61, which also cuts off communication between said opening and said vacuum chamber through said passageway. The'removal of this plug permits the application of heat to the air passing through the inlett fitting to the intake manifold in order to facilitate starting of the engine during cold weather. readily applied to the air passing through the air inlet fitting E without removing the large air cleaner (not shown) mounted on the spider 22 on the upper or main air inlet end of said fitting.

When the plug 61 is removed from the auxiliary air inlet opening 65 in the air inlet fitting E, there is a direct flow of air from said opening into the air intake manifold A of the engine, with theresult that the vacuum in the air inlet venturi 24 is not sufficient to open the spring-loaded check valve 23 in the hollow stud 26 which opens By this arrangement heat may besageway 69, annular chamber 5.8 and-radial ports 51, and thence through the suction pipe l8 to the vacuum chamber 2 of the main governor D. By this arrangement, the vacuum in the hollow stud 26 inwardly of the valve 23 therein tends to hold said valve to its'seat and causes the two governors D and F to operate in the manner hereinbefore described to control the quantity of fuel.

supplied to the engine according to the variation of such vacuum. Should the engine gain too much speed with the throttle valve 21! open and the plug 61 removed, the throttle valve is closed so that all the air will enter the inlet fitting through the auxiliary Venturi inlet opening 65, which will transmit enough vacuum to the main governor D to cause the latter to decrease the fuel supply and thus hold the engine to a safe speed.

In the event of unintentional reverse running of the engine, the engine exhaust flows through the inlet manifold A and produces an excess pressure therein, which pressure, were it not for the check valve 23, would be transmitted through said stud and the tube l8 to the governor chamber 2 and move the fuel feed contrc member C to maximum fuel feed position and also'prevent the operator from moving the diaphragm or movable wall 3 of said chamber to fuel cut-off position. With the present arrangement, however, the pressure produced in the intake manifold A by the reverse running of the engine causes the valve 23 to close and thus prevents such pressure from being transferred to the chamber 2 of the main governor and causing the same to increase the quantity of fuel supplied to the engine. This cutting off of the pressure from the governor chamber 2 during the reverse running of the engine also enables the movable wall 3 of the governorto be readily moved by the operator to fuel cut-off position.

If the engine unintentionally runs in reverse when the plug 61 is removed, an exhaust pressure is created in the inlet manifold and this exhaust pressure escapes through the inlet passageway 2| of the inlet fitting E and through the auxiliary inlet opening 65. The passage of'the exhaust pressure through the Venturi opening 65 creates a vacuum at the throat thereof which is transmitted through the passageway 66 to the chamber 30 where it operates the auxiliary governor to close the throttle valve 21. At the same time, the

. vacuum is transmitted to the main governor D through the passageways 59 and I8 to operate the fuel control member C and cut-off flow of fuel to the engine, the check valve 23 preventing the pressure in the inlet passageway 2| from being transmitted through the conduit l8 to the main governor D.

The hereinbefore described arrangement admits of considerable modification without departing from the invention. Therefore, I do not wish to be limited to the precise arrangement shown and described. I

What I claim is:

1. In an automatic fuel feed control for an internal combustion engine, an air intake manifold, an adjustable throttle valve for said manifold, a main governor responsive to the vacuum in said manifold for controlling the quantity of fuel supplied to said engine according to the variation of the vacuum in said manifold, and an auxiliary governor operatively connected to said throttle valve and responsive to. a predetermined vacuum in said intake manifold to move said valve towards closed position from any open adjusted position thereof to thereby increase the vacuum in said manifold and thus accelerate the movement of said main governor in the direction of minimum fuel delivery.

2. In an automatic fuel feed control for an internal combustion engine, an air intake manifold, an adjustable throttle valve in said manifold, a main governor responsive to the variation of the vacuum in said intake manifold at different engine speeds in the different positions of adjustment of said throttle valve for controlling the quantity of fuel supplied to said engine, a second governor operatively connected to said throttle valve and responsive to a predetermined vacuum in said air intake manifold in all positions of adjustment of said valve to move the same towards closed position to thereby increase the vacuum in said manifold and thus accelerate the movement of the main governor in the direction of reduced fuel feed, said second governor being adapted to return said throttle valve to its initial position of adjustment when the vacuum in said intake manifold decreases below such predetermined vacuum, and means for adjusting said second governor to vary the amount of vacuum required to impart such closing movement to said throttle valve.

3. In an automatic fuel feed control for combustion engines, an ai intake manifold, a throttle valve for said manifold, means for adjusting said throttle valve, a main governor responsive to the vacuum in said manifold for controlling the quantity of fuel supplied to said engine according to the variation of the vacuum in said manifold, and a second governor having a vacuum chamber which communicates with said manifold and has a movable wall operatively connected to said throttle valve adjusting means for moving said valve towards closed position in all positions of adjustment thereof at a predetermined vacuum in said manifold to thereby increase the manifold vacuum and thus accelerate the movement of said main governor in the direction of reduced fuel feed, a spring cooperating with said movable wall for returning said throttle valve to its position of initial adjustment when the manifold vacuum falls below said predetermined vacuum, means for varying the force of said spring to render said movable wall responsive to different degrees of manifold vacuum, said manifold having a Venturi air inlet opening therein between said valve and engine, a passageway leading from said vacuum chamber to said opening, and a removable closure for said opening and said passageway. I

4. In an automatic fuel feed control for combustion engines, on air intake manifold, an air inlet fitting for said manifold having a Venturi air inlet passageway, an adjustable throttle valve in said Venturi passageway, a main governor communicating with said Venturi passageway and responsive to the vacuum in said manifold for controlling the quantity of fuel supplied to said engine according to the variation of the vacuum in said manifold, and a second governor having a vacuum chamber in said fitting that communicates with said Venturi passageway and has a movable wall operatively connected to said throttle valve for moving the same towards closed position from any open adjusted position thereof at a predetermined vacuum in said manifold to thereby increase the manifold vacuum and thus accelerate the movement of said main governor ascents in the direction of reduced fuel feed, and for re turning said throttle valve to its position of initial adjustment when the manifold vacuum falls below said predetermined vacuum.

5. In an automatic fuel feed control for combustion engines, an air intake manifold, an air inlet fitting for said manifold having a Vcnturi air inlet passageway, anadiustable throttle valve in said ll'enturi passageway, a. main governor communicating with said Venturi passageway and responsive to the vacuum in said manifold for controlling the quantity of fuel supplied to said engine according to the variation of the vacuum in said manifold, and a second governor having a vacuum chamber in said fitting that communi-' cates with said Venturi passageway and has a -movable wall operatively connected to said throttle valve for moving the same towards closed position from any open adjusted position thereof at a predetermined vacuum in said manifold to thereby increase the manifold vacuum and thus accelerate the movement of said main governor in the direction of reduced fuel feed, and for returning said throttle valve to its position of initial adjustment when the manifold vacuum falls below said predetermined vacuum, said inlet fit ting having a second Venturi air inlet opening and a passageway leading from said second venturi to said vacuum chamber, and a removable closure for said second venturi and said last mentioned passageway.

6. In an automatic fuel feed control for an internal combustion engine, an air intake maulfold for said engine, s. butterfly throttle valve for said manifold, a main governor responsive to the vacuum in said manifold for controlling the quantity of iuel supplied to said engine according to the variation of the vacuum in said manifold, a shaft for said throttle valve, an arm rigid with said shaft, a throttle shaft disposed parallel with said valve shaft, an operative connection between said throttle shaft and said valve I shaft including a crank arm on said throttle shaft, a crank pin on said crank shaft, a pivot disposed parallel with said shafts and movable transversely thereof, a rock lever pivotally supported on said pivotand pivotally connected atv one end to said crank pin, a link connecting the other end of said rock lever to the arm on said valve shaft, and a second governor including a diaphragm operatively connected to said pivot fold having a main air inlet opening and auxiliary Venturi air inlet opening, an adjustable throttle valve in said manifold between said main and auxiliary air inlet openings, a pump for supplying fuel to said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a vacuum chamber, a conduit laminar outing at one end with said chamber and at the other end with said manifold adjacent to said throttle valve, said chamber having a movable wall operatively connected to said control memher and responsive to a predetermined vacuum for moving said control member in the direction of reduced fuel feed, a check valve in said con= duit held open by the vacuum in, said manifold during the forward running of said engine, said I conduit communicating at one end with the vacand responsive to a predetermined vacuum in said manifold to shift said stud transversely and to thereby swing said rock lever about the axis of said crank pin and thus move said valve towards closed position from any open adjusted position thereof through the link connections between said rock lever and the arm on said valve shaft.

vacuum chamber of said main governor and having a movable wall operatively connected to said throttle valve for moving the same towards closed position from any open adjusted position thereof at a. predetermined vacuum in said manifold to thereby increase the manifold vacuum and thus accelerate the movement of said main governor in the direction or reduced fuel feed, and for returning said throttlevalve to its position oi initial adjustment when the manifold vacuum falls below said predetermined vacuum, said'inlet fitting having an auxiliary Venturi air inlet opening between said throttle valve and said manifold, a passageway leading from said auxiliary air inlet opening to said vacuum chamber of said second governor, and a. removable closure for said auxiliary air inlet opening and said last

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