US2904025A - Internal combustion piston engine - Google Patents

Description

Sept. 15, 1959 SCHERENBERG ETAL INTERNAL COMBUSTION PISTON ENGINE Filed March 23, 1954 ,8 27 30 :6 2a (2a J: 29 32 3 35 35 /3 a u 3" 2a m 3 8 I m 2/ INVENTORS.

HANS 0.5CHERENBERG 8 RUDOLF E. UHLENHAUT.

. ATTORNEYS.

air intake duct.

States Patent INTERNAL COMBUSTION PISTON ENGINE Hans 0. Scherenberg, Stuttgart-Heumaden, and Rudolf ,E. Uhlenhaut, Stuttgart, Germany, assignors to Daimler-Benz .Aktiengesellschaft, Stuttgart-Unterturkheim, Germany Application March-2s, 1954, Serial No. 418,194 Claims priority, application Germany March 26, 1953 14 Claims. (Cl. 123-140 Our invention relates to an internal combustion piston engine of the type in which the fuel is injected into the cylinder, preferably during the compression stroke of the piston for compression and subsequent ignition by a spark plug. More specifically, the present invention is concerned with the means for controlling the admission of air and fuel to the cylinder.

In engines of this type, the temperature has a considerable influence on the ratio measured by weight of the air charge to the quantity of fuel injected into and mixed with such air. at the instant of ignition.

This influence is of a dual nature: On the one hand, the specific weight of the air charge and thus the number of oxygenmolecules per space unit varies as the temperature changes so thatcold air will result in a more meager mixture thanwarm air if the pressure of the air charge and the quantity of the fuel injected per ignition remain constant. On the other hand, the temperature of the walls contacted by the combustion air is of controlling influence, because it will influence the temperature of the air charge prior to the ignition and it may cause a smaller or larger proportion of the quantity of fuel injected to condense on the walls and to be thus absent in an ignitable form within the air charge at the instant of ignition.

'In'piston engine of the type to which the present invention relates, there are provided an adjustable control member coordinated to the fuel pump and adapted to variablydetermine the quantities of fuel intermittently injected into the cylinder and a main throttle valve in the Moreover, there are means responsive to the adjustment of the main throttle valve and adapted to adjust the pump control member. Consequently, when the adjustment of the main throttle is altered to thereby vary the pressure and consequent weight of the air charge, the quantity of fuel injected is varied accordingly so as to keep the ratio of mixture at an optimum value.

More. particularly, the means responsive to the adjustment of the main throttle valve includes a linkage connecting 'the'main .throttle valve to the control member. Alternatively, the means responsive to the adjustment of the main throttle valve may comprise a vacuum-responsive diaphragm or piston connected to the adjustable pump jected to the vacuum prevailing in the intake duct, such vacuum depending on the position of the main throttle valve which, as a rule, is formed by a butterfly valve. It is the object of the present invention to provide improved means for controlling the air charge in relation to the quantity of fuel injected into the cylinder preparatory to any ignition, such control to be effected in de- 2,904,025 Patented Sept. 15, 1959 pendence on the temperature so as to avoid any undesired influence of the temperature onthe ratio of the air-fuelmixture.

More specifically, it is an object of the present invention to provide an auxiliary air throttle valve controlled by temperature-responsive means so as to automatically adjust the desired ratio of the air-fuel-mixture when the temperature of the combustion air and/ or of the walls contacted thereby changes.

Further objects of the invention are to provide an auxiliary air throttle valve for easy adjustment by the temperature-responsive means so that the latter must produce a slight force only for effecting the adjustment, as distinguished froman arrangement in which the temperature-responsive means are effective to adjust the fuel pump and, therefore, must produce a powerful adjusting force. Expressed in other words, it is the object of the present invention to effectuate a temperature control by means of a simple thermostat of the bi-metal type.

Further objects of the invention are to minimize the reaction of the auxiliary throttle valve on the vacuum tap connected with the pump-adjusting diaphragm chamber, and to minimize the dimensions of the auxiliary throttle valve.

Further objects of the present invention will appear from a detailed description following hereinafter of a number of embodiments of the present invention, and the features of novelty will be pointed out in the claims. It is to be understood, however, that such detailed description serves the purpose of illustrating the invention rather than that of limiting the same. In the drawings,

Fig. 1 shows a more or less diagrammatic axial section through a cylinder of an internal combustion piston engine provided with a fuel injection pump and a main throttle valve in the intake duct, means being provided to control the quantity of fuel injected at any time in direct dependence of the position of the main throttle valve,

Fig. 2 is a sectional view similar to that of Fig. 1 of an internal combustion piston engine differing from that shown in Fig. l in that the quantity of fuel injected at any time is controlled in indirect dependence of the position of the main throttle valve, both examples of the invention shown in Figs. 1 and 2 being characterized by the disposition of a thermostat-controlled auxiliary throttle valve in the intake duct,

Fig. 3 is a view similar to that of Figs. 1 and 2 of an internal combustion piston engine difiering from that shown in Fig. 2 by the disposition of the thermostat-controlled auxiliary throttle valve in a bypass duct communicating with the main intake duct,

Fig. 4 is an axial section taken through the outer end of the intake duct provided with the main throttle valve and with an auxiliary throttle valve in form of a needle valve disposed in a bypass duct, and

Fig. 5 is a view similar to that of Figs. 1 and 2 of an internal combustion piston engine in which the thermostate controlling the auxiliary throttle valve is responsive to the temperature of both the combustion air and the cooling liquid.

The internal combustion piston engine comprises a cylinder block '10 including four cylinders provided with a cooling jacket 11 and with a cylinder head 12 which has intake ducts 13 controlled by intake valves 14 and outlet ducts :15 controlled by outlet valves 16. The cylinder head is provided with a lateral bore located adjacent to the compression space 17 and adapted to accommodate a fuel injection device 23 of any suitable type which is connected by a fuel pipe 18 to one of the four outlets "19 of a fuel pump 20, one outlet being provided for each cylinder of the engine. The pump 20 is geared to the customary cam shaft controlling the valves 14 and 16, the cain shaft being geared in its turn to'the'crankshatt actuated by the piston 21 through the intermediary of a connecting rod 22. The fuel pump feeds intermittently quantities of fuel to the injection deviee23ofeach cylinder and'isso timed that the injectionof the fuel takes place while the'intake valve 14 is open and the piston 21 sucks air into the cylinder thrQ i'gh the intake duct '13.

'The intake duct '13 communicates with an inlet duct 24 'in which a main'throttle valve inform of a'butterfly valve 25 is inserted.

epump is provided with an adjustable control member in form of a control rod 26which,'for' the purpose of varying the quantities of fuel, is shiftably mounted 'i'njih pump 20 in the direction of its axis.

The power produced by the engine may be controlled 'by a'threje-armed lever '27 having one'arm provided with ahandle 28 and adapted to be rocked'about a stationary ftilcriim 29. Another arm of lever 27 is connected 'by 'alink to the control rod 26, and a third of the lever 2 7'is connected by a link 31 to an arm-32 "fixed to the outer end'of the shaft of the butterfly valve 25. Ifdesired, lever 27 may be connected with a governor. When the'handle 28'is depressed to reduce the power output of the internal combustion piston engine, the throttle is moved towards its closed position, whereby the weight of the air charge admitted into'the cylinder 10 is reduced. By the same adjustment of the threea'rnied lever 27 control rod 26 is moved to the left, whereby the fuel'quan'tities intermittently fed by pump 20 through pipe 18 to the injection device '23 are rediiced accordingly to thereby keep the ratio of mixture ofair and fuel'constant irrespective of the power output. y

Thus, it will appear that the linkage 31, 27, con- 'necting the main throttle valve '25 to the control member 26 eonstitut'es, in effect, a means which is responsive to the adjustment of the main throttle valve 25 and is adapted to" adjust the control member 26.

For the purposes of the present invention we have providd an auxiliary throttle valve which may take the form of a butterfly valve '33 mounted in the inlet duct 24, and we have furthermore provided temperature-responsive means in form of'a thermostat 34 of the bi-metal type, the movablearm 35 of the latter being connected by a link '36 to an arm 37 fixed to the outer end of the shaft of the butterfly valve 33, the latter being so adjusted thatit is adapted to unthrottle the flow of air through the'inlet duct 24 and the intake 13 intothe-cylinder 10 'when the temperature of the thermostat 34 increases. In the embodiment shown the thermostat member '34 is mounted in a bore provided in the wall of duct 24, and its temperature-sensitive element 38 projectsinto the duct 24 to be subjected to the flow of air-therethrough.

Hence, the temperature-responsive means is mounted to respond to the temperature of the air sucked into the inlet duct 24.

The operation of the controlling system is as follows:

A'predetermined position of the main throttle valve 25 and of the adjustable control member 26 is allotted to any position of lever 27. In this manner, such quantity Qt'fuel will be injected into the cylinder 10 for any ignition as corresponds to'the weight of the air charge determined by the position of the main throttle valve 25.

Should the temperature of the air drop, the auxiliary throttle 33will be so turned as to increase its throttling efiect upon the flow of'air through the inlet duct 24. As 'a' result,the volume of the air charge supplied to the cylinder 10 will 'be somewhat reduced without affecting the quantity of fuel injected. Under normal conditions, the throttling effect produced by the auxiliary throttle valve 33-can be 'so selected that the weight of the air charge supplied to the cylinder 10 for any ignition will remain constant, thus ensuring an invariable ratio of mixture of fuel and air. Should the'temperature of the air flo'wing through inlet duct 24 'rise, the auxiliary throttle valve 33 will be so adjusted by the temperatureresponsive means 34 as to 'unthrottle the flow'of air.

The embodiment of the t-present invention illustrated in Fig. 2 is identical with that shown in Fig. 1 in many respects, and, therefore, the same reference numerals have been applied to the corresponding elements. This embodiment, however, differs from that shown in .=Fig. by the absence of the lever 27, the controlmember 26 being connected 'to a movable"wall*member,"suchasfa diaphragm 39, ofla'vacuum chamber 40 connected by a tapping pipe 41 with the inlet duct 24 'at a'point 42vwhere the vacuum prevailing in the duct 24 depends on the position ofthe main throttle'valve 25.' Therefor-efithe vacuum prevailing-at the point 42;depending on the position of the throttle valve 25 will be transferred to the vacuum chamber 40. Depending onthe degree of such vacuum, the diaphragm 39 will be bent thereby adjusting control member 26 accordingly. In this manner, the quantity of fuelinjected will increase 'when'the absolute amount of' the pressure prevailing in the inlet-ductfl at the point42increases. Thus, vthe di'aphragm"39constitutes a meansrespons'ive'to the adjustment-ofthemai'n throttle valve 25 andadaptedto'adjustthe control member '26. i

A third embodiment of the'prese'nt'invention is illustrated in Fig. 3 which'in'many respects is identical with that shown'in Fig. 2, asindicatedby theuse of the same reference numerals for the corresponding elements. Thus, the controlmember 26 isadju'sted by a diaphragm 39 of a vacuum chamber'40 connected to apoi'ntf42 of inlet duct 24 by a pipe 41. I-Iov'vever, thisembodiment differs from that shown in 'Fig. j2by'the disposition of the auxiliary throttle'valve; Thisjauxiliar'y'thiottle valve 333 is contained in a'n-aiixiliary duct" 43 which bypasses the main throttle valve 25 preferably br'anchesofi the inlet duct '24 at a'poi'nt'44 located outside the'main throttle valve 25. Alternatively, however, duct qs'may open'into'the atmosphere at any desired point. The exterior end of the shaft of the. throttle 'va1 ve 333 has an arm 337 which is connected'by a link 336 to the 'movable end of the thermostat 334, the arrangement i'bein'g such that a contraction'of the temperatiire responsi've'ele; ment 334 caused by a drop of the temperature of thefair passing through duct '24 will 'throttleduc't 43 "thereby reducingthetotal volume of air's'ucked intocyliiider 10 through both of the'ducts 24and43.

The embodiment illustrated infFig. 4v is 'similar in many respects'to that shown inFig. 2' differing therefrom, however, by'the absence of 'thebutterfly [van e33 and by the provision of the following means:"The'pipe 41 leading to'th'e diaphragm ohambe'r'40communicates with a radial bore "45 provided'inthe wall ofthe inltduct '24 leading to point-42 which, ssailedabove, 'is 'located between the main throttle valve 25 and the 'intake'13 of the engine. Bore 45has a'bran'ch '4'6i'which themain throttle valve 25 leading to a bore47"comm'unieating-With the atmosphere, forihstance' at a 48"of duct 24 outsideof main throttle'valve '25. Theboi'e'j' t l is provided witha valves'eati'coope'rating Witha needle valve 433fvv'h'ereby the newer through meanes and 46 maybe rammed. '"Ntwo' aimedflever'fiilcrunied on a bracket 50 rigid with'the'wallof duct 24 has 'one arm 49 connected to the'inovable"end of a bifmetal'thermediate those'pressures which prevail 'at'th'e points 42 and 48. Therefore, thevacuumin pipe 41jis less'povvertul than that prevailing at fthe'point 42 I When the'tempeiiat e i r e t sii ifiist istre ilt i ltl asstat 434 wil l contract rocking lever 49, 51 anti-clockwise, whereby bore 47 will be unthrottled thereby further reducing the vacuum in pipe 41. As a result, the control member 26 is shifted to the right thereby increasing the quantity of fuel injected in proportion to the increase of theweight of the air charge, the latter increase being due to the drop of the temperature of the air. Hence, it appears that the bores 46 and 47 constitute an auxiliary duct which bypasses the main throttle valve 25 and contains the auxiliary throttle valve 433.

' Fig. shows an'alternative disposition of the temperature-responsive element, the same being formed by a bi-metal thermostat 534 mounted in thecoolingjacket 511 of the cylinder head, its temperature-responsive member 538 extending through a bore in the lower wall of the intake 13- so as to be responsive to both the temperature of the cooling medium circulating through the jacket 511 and to the temperature of the air flowingthrough inlet duct 24 and the intake 13. Otherwise, the embodiment shown in Fig. 5 may be similar to any one of those described with reference to Figs. 1, 2, 3 and 4, a suitable linkage 536 being' provided to connect the movable element of thermostat 534 to the auxiliary throttle valve 33 or 333 or 433.

While We have described our invention with reference to'a number of specific embodiments thereof, we wish it to be clearly understood that the same is capable of numerous modifications within the scope of the appended claims and is in no way restricted to the details shown. Thus, the injection device 23 need not be located at the point illustrated.

What we claim is: n 1

1. In an internal combustion piston engine, the combination comprising a cylinder, a fuel injection device mounted to inject fuel into said cylinder, inlet and outlet valves mounted on said cylinder, an inlet duct controlled by said inlet valve, a fuel pump geared to the engine and connected with said injection deviceand adapted to intermittently feed quantities of fuel to said injection device, a main throttle valve in said inlet duct, an adjustable control member operatively connected to said pump and'adapted to variably determine said quantities of fuel, means responsive to the adjustment of said main throttle valve for adjusting said control member, means in said engine responsive only to temperature changes within said engine that are proportional to the temperature of the air fed to the cylinder, an auxiliary throttle valve controlled by said temperature-responsive means to vary the air charge admitted to the cylinder through said duct in relation to said quantity of fuel when said temperature changes.

2. The combination claimed in claim 1 in which said means responsive to the adjustment of said main throttle valve includes a linkage connecting said main throttle valve to said control member.

3. The combination claimed in claim 1 in which said means responsive to the adjustment of said main throttle valve comprises a chamber having a movable wall member connected to said adjustable control member and a conduit connecting said chamber to said inlet duct at a point where the vacuum prevailing in said =duct depends on the position of said Imain throttle valve.

4. In an internal combustion piston engine, the combination comprising a cylinder, a fuel injection device mounted to inject fuel into said cylinder, inlet and outlet valves mounted on said cylinder, an inlet duct controlled by said inlet valve, a fuel pump geared to the engine and connected with said injection device and adapted to intermittently feed quantities of fuel to said injection device, a main throttle valve in said inlet duct, an adjustable control member operatively connected to said pump and adapted to variably determine said quantities of fuel, means responsive to the adjustment of said main throttle valve for adjusting said control member, means in said engine responsive only to temperature changes 6 within said engine, an auxiliary throttle valve controlled by said temperature-responsive means and adapted to vary the air charge admitted to the cylinder through said duct in relation to said quantity of fuel when said temperature changes, said temperature-responsive means being mounted in said engine to respond to the temperature of the air sucked into said inlet duct.

5. The combination claimed in claim 1 in which said means responsive to the adjustment of said main throttle valve comprises a chamber having a movable wall member connected to said adjustable control member and a conduitconnecting said' chamber to said inlet duct at a point where the vacuum prevailing in said duct depends on the-position of said main throttle valve, said auxiliary throttle valve beingdisposed in 'said inlet duct-between said point and said inlet valve.

I 6. The combination claimed in claim 1 in which said inlet duct communicates with-an auxiliary duct bypassing said main throttle valve and containing said auxiliary throttle valve.

7. The combination'claimed in claim 1 in which said means responsive to the adjustment of said main throttle valve comprises a chamber having a movable wall member connected to said adjustable control member and a conduit connecting said chamber to said inlet duct at a point where'the vacuumprevailing in said duct depends on the position of said main throttle valve, and in which said inlet duct between said point and said inlet valve communicates with an auxiliary duct bypassing said main throttle valve and containing said auxiliary throttle valve.

8. The combination claimed in claim 1 in which said means responsive to the adjustment of said lmain throttle valve comprises a chamber having a movable wall member connected to said: adjustable control member anda conduit connecting said chamber to said inlet du'ct at a point Where the vacuum prevailing in said ductdepends on the position of said main throttle valve, and in which said inlet duct between said point and said inlet valve communicates with an auxiliary duct which bypasses said main throttle valve and contains said auxiliary throttle valve and branches off said inlet duct at a point outside of said main throttle valve.

9. In an internal combustion piston engine, a cylinder, 2. fuel injection device for injecting fuel into said cylinder, inlet and outlet valves mounted on said cylinder, an air inlet duct controlled "by said inlet valve, a=fuel pump geared to the engine and connected with said injection device and adapted to intermittently feed quantities of fuel to said injection device, a main throttle valve in said inlet duct, an adjustable control member operatively connected with said pump to variably determine said quantities of fuel, vacuum-responsive means connected to said control member for the adjustment thereof, a conduit connecting said vacuum-responsive means to a point of said inlet duct, said conduit being provided with an inlet port, a control valve controlling said inlet port, and temperature-responsive means in said engine responsive only to temperature changes within said engine that are proportional to the temperature of the air fed to the cylinder and connected with said control valve to throttle said inlet port when the temperature increases.

10. In an internal combustion piston engine, a cylinder, a fuel injection device for injecting fuel into said cylinder, inlet and outlet valves mounted on said cylinder, an air inlet duct controlled by said inlet valve, a fuel pump geared to the engine and connected with said injection device to intermittently feed quantities of fuel to said injection device, a main throttle valve in said inlet duct, an adjustable control member operatively connected with said pump to variably determine said quantities of fuel, vacuum-responsive means connected to said control member for the adjustment thereof, a duct connecting said vacuum-responsive means to a point of said inlet duct located downstream of said main control valve, said duct being provided with an inlet port tenminating Q in,;'said;duct upstream of said main controlvalve, a fureontrol valve controlling said .-inlet vporhsand-temprimate-re pon ive means in. i eng neconne t .i BSiQg'WI'xCODiIOl.'VBlW/6 to throttle said, inlet port lpon increases in :temperature within said engine that are proportional ,to the @temperature efthe air fed .to the cylinder. 1 II n. 1-1xIn-'an.-imemal combustionv piston engine, the'comv'comprising a cylinder, -a -fuel injection devicev mounted toln'jcet :fuel into .said cylinder, inlet and outlet; valves mounted on said :cylinder, an inlet duct con-, trollodbysaid ,i'nlet. valve,,-a*fuel pump geared tothe connected with said injectiondevice and adapt c'dato. intermittently Efeed quantities of fuel to said injecv tiohldevice, a mainathrottle valvein said, inlet-duct, an adjustable control member-nperativelyconnected to said pump and adapted. to, variably determine said. quantities obfuel, means responsiveto the adjustment-of said rnain throttle valve for adjusting said :control. member, means in said engine responsive only to temperature changes within'sdid engine, an auxiliarythrottle.valve-controlled byn'said."temperature-responsive. means and adapted to vary the xair oharge admitted to the cylinder vthrough said ductnin relationto said quantity of fuel when said temperature changes, said ftemperature-responsive, means being mountedlin said engine to respond to the temperaturecftihe wall ofsaidinlet duct. 12. Iran internal co'mbustionrpiston engine having a coolingjackt thro'ughwhich a :coolingmedium circulates,- the combination.- comprising arcylinden; a fuel injection idevicc mounted .to inject fuel into said cylinder, inlet'andzoutlet valves imounted onv said. cylinder, an inletiductcontrolled'bysaid inlet'valve, a fuel-'pump'geared toirhe engine.-and.connected.:v vith' said injection device and. adapted :to intermittently, 'feed,;quantities .of fuel .to said injection device, a mainthrottle valve in said inlet ductgan adjustable co'ntrol member operatively connectedkto said' pumpand adapted to variably determine said 'qixantitiesqof fuel, means responsive to the adjustment ofv'said main throttle valve for adjusting said control number, means in said engine responsive only -to temperature changes within said; engine, an auxiliary throttle valves-controlled. by said temperature-responsive "means and adapted -to vary the-air charge admitted. to the cylinder 'through said' ductin relation to said quantityof fuel when said temperature changes, said temperature-responaive means being mounted to respond to the temperature of saidcoolin'g-medium.

13.5111 an internal combustion piston engine, the'combinatidncomprising a cylinder, a -'fuel injection device moimted -to inject -fuel into. said cylinder, inlet and outlet-valves mounted; on said cylinder, .an -inlet duct contIOllQdfiby said-inlet yalve,;a fuel ;pump geared -to the engineandconnected with saidinjectiondevice and adapt ed to intermittently iced quantities {Of -;f;l1 LtO said-injection device, a main throttle ,valve in sa d inlet duct, an adjustable control member operatively connected to said p mpa a ap dnv a y determine d quan ti s of fuel, means-responsive to the adjustment of said main throttle valveior, adjusting said control member, means in said engine responsive only. to temperature changes Withinsaid engine, an auxiliary throttle valve controlled by. said temperature-responsive means and adapted to y the 1; air; cha g admitted t h tcy nde thr said -duct in-relation to said, quantity of fuel when said temperature changes, :sai'd temperature-responsive means being a thermostatic element responsive to temperature changes only and exposed to the-air flowing in said inlet duct. v

-14. Inqan internal combustion piston engine having a cooling jacket through which a cooling medium circulates, =the-combination comprising a cylinder, a fuel injection device mounted to -injectv fuel into said cylinder, inlctrand'outlet valves mounted on 'saidcylinder, aninlet duct controlled by said inlet valve, 21 fuelpump geared -to the engine and-connected with said injection device and adapted to intermittently-feed quantities of fuelto injection-device, amain throttle valve in said inletduct,v

anadjustable'control memberoperatiyely connected to said pump and adapted to variably determine said quantities of fuel, means responsive -to the adjustment of said main throttle valve for adjusting said control member, means in said engine responsive only to temperature ohangesrwit-hin said engine, an auxiliary throttle valve controlled by,saidtemperature-responsive means and adapted to =vary=theair charge admittedto the cylinder through said duct. in relation to said quantity of fuel when said temperature changes, said temperature-responsive means being mounted to respond'to the temperature of both said cooling, medium and the, air flowing through said inletqduct'. v v

-Referen ces Cited in the file of this patent UNITED STATES PATENTS I 'OTHER "REFERENCES Serial No. 376,679, Fuscaldo (A. P.C.),. -published May 11, 1943.

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