US2759717A - Valve control mechanism - Google Patents

Description

3955 F. K. H. NALLENGER VALVE CONTROL MECHANISM Filed May 5. 1950 INVENTOR ERIEDRICH K. H. NALLINGER MW M c0;

AGENTS United States Patent VALVE CONTROL MECHANISM Friedrich K. H. Nallinger, Stuttgart, Germany, assignor to Daimler-Benz Aktiengesellschaft, Stuttgart-Unforturkheim, Germany Application May 5, 1950, Serial No. 160,235

Claims priority, application Germany May 9, 1949 2 Claims. (Cl. 261-41) This invention relates to the control of internal combustion engines, particularly of carburetor type internal combustion engines for motor vehicles.

More particularly, the present invention relates also to the control of internal combustion engines provided with carburetors which have one or more fuel jets. One of these jets serves, for example, as compensating jet which is opened or placed into operation as soon as the carburetor throttle valve is opened immediately following the idling speed and which remains effective until the throttling valve reaches a definite position. The second or even the third jet is opened or placed into operation only after a predetermined travel or movement of the throttle valve by means of a suitable control element or linkage, or, for example, by means of the variations of vacuum in the inlet manifold of the internal combustion engine.

Accordingly, it is an object of the present invention to provide operating controls for internal combustion engines which assure utmost economy in the operation thereof even when operated by drivers or operators with but little experience.

It is another object of the present invention to provide such a control arrangement for internal combustion engines as to advise the operator or driver of the vehicle when the point of most economical fuel consumption is reached.

A further object of the present invention resides in the provision of such an arrangement which enables the sequential opening or placing into operation of the different fuel jets in such a manner that one or several fuel jets are opened or placed into operation only after giving the driver a perceptible notice that the point of economic fuel consumption is about to be passed.

A still further object of the present invention resides in the provision of such a control arrangement which offers a definite perceptible resistance at the point of optimum fuel economy.

Accordingly, an important feature of the present invention consists essentially in that a predetermined resistance must be overcome by the driver or operator of the vehicle prior to the increase in fuel delivery beyond that available. at a definite intermediate control position which corresponds and assures an economical fuel consumption, or prior to the adjustment to a control position allowing increased fuel delivery to the engine beyond the predetermined point providing economic operation of the vehicle, for example, by opening or placing into operation a second or additional fuel jets.

Among the advantages secured by the present invention is the fact that the fuel consumption with a good average engine speed or average road speed of the vehicle, for example, with the transmission in high gear, may be kept very low by operating the engine only with that one or with those fuel jets which assure economic fuel consumption and by preventing that the addiitonal jet or additional fuel jets are normally opened or placed into operation by the driver unconsciously and inadverice tently by merely depressing the accelerator pedal down beyond a point of economic fuel consumption. Thus, by locating the point of resistance corresponding to this economic fuel consumption in such a manner that this point is made clearly perceptible to the driver when it is passed so that ordinarily the driver operates the vehicle within a range defined by this point, a most economical vehicle operation is made possible even for a less experienced driver which was unattainable to an equal degree even by a skilled driver with the ordinary control arrangements of the prior art.

Further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows for purposes of illustration only two embodiments in accordance with the present invention and wherein:

Figure 1 is a schematic arrangement of a control system in accordance with the present invention and,

Figure 2 is a partial view of a modified embodiment of the control system for internal combustion engines in accordance with the present invention.

Referring now to the drawing and more particularly to Figure l, the reference character a designates the air intake of the carburetor which intake a is provided with a venturi b and the usual throttle valve c. Two fuel jets d and e are arranged concentrically to one another within the venturi b. However, it is understood that other jets, not shown herein, such as an idling jet, starting jet, mixing nozzle or the like may be provided in addition to the jets shown herein. The jets d and e draw the fuel from the float chamber 1 and may be opened or placed into operation and closed or placed out of operation in any suitable manner, for example, by means of valves, stop-cocks, throttle valves or the like. The control levers of the schematically illustrated valves g and h are linked to the carburetor control rod k by means of linkage i and bell-crank 1' or in any other suitable manner. If necessary, suitable play may be provided in the linkage so that the various valves g and h are: moved or opened only sequentially, as is well known. The carburetor control rod k which operates the throttle valve c in the usual manner and which is spring biased by means of spring I is operated by the operator by means of the accelerator or gas pedal m. A spring loaded stop n which is retained in a definite predetermined position by means of spring 0 and counterstop p is arranged within the range of travel of the accelerator pedal m.

In Figure 1 of the drawing, the throttle valve 0 is shown in the idling position thereof corresponding to the posh tion co of its control lever, indicated in full lines. As the accelerator pedal m is depressed and moved from its idling position mo to the position 1111, throttle valve 0 is gradually opened up to the postion c1 of the control lever thereof. At the same time, the linkages i and the bell-crank j and possibly also at first only the linkage of the jet d, if a suitable play is provided in the linkage with jet e, are moved in unison with the throttle valve control rod k. As a result thereof, the valve g is gradually opened whereby the jet 0 is brought into communication with the float chamber f by the opening movement of the valve g, i. e., by the movement of the valve g from the closed position go to the position g1 of its control lever. At the same time, the fuel line for the additional jet e remains shut off as the valve h in the position I11 of its control lever fails to provide a communication between the additional jet 2 and the float chamber In the position ml the accelerator pedal rests against the stop it. In that position, the engine controls are adjusted for economical fuel consumption. The accelerator pedal can only be further depressed by overcoming the resistance of the resilient stop n, which, accordingly,

acts as a point of resistance. Such further depression, however, may be desired at times in order to obtain maximum power from the engine for either high-speed or low-speed, high-torque operation of the engine even though the fuel consumption is thereby affected detrimentally.

As the accelerator pcdal m is moved from the position 1111 into the position m2 throttle valve is also moved to the fully opened position c2 of its control lever while the throttle valves g and h reach the positions corresponding to the positions gz and he of the respective control levers thereof. By moving the control lever of valve g from the position gr to g2 the fuel line for the jet d remains open. As the control lever of valve h is moved from its position hi to 122, the valve h is gradually opened and the additional jet 6 is thereby opened or placed into operation by being placed into communication with the float chamber f. If so desired, the opening or placing into the operation of the additional jet e may also take place only after the throttle valve 0 has already reached. or has almost reached its end position to provide the largest cross-sectional area for the passage of the air.

In the embodiment according to Figure 2, a disk cam s is arranged on the throttle valve shaft f. The carn s is provided with a cam portion s1 having a relatively smaller radius and a cam portion s2 of relatively larger radius, the cam portions s1 and sz being connected with each other by the rising cam portion s3. A cam roll or follower v is rotatably supported on a lever t which itself is swingably supported in any suitable manner, for example, in a bearing bracket secured to the inlet manifold. Continuous contact between the cam follower v and the cam surface of the cam s is assured by a spring 11.

In the lower control range, in which the first jet or corresponding group of jets d is opened or placed into operation, the cam follower v moves along the cam portion st of the cam s in such a manner that a carburetor control is assured within this control range for economic fuel consumption. If, however, the additional jet or jets e are to be opened or placed into operation by a further movement of the control rod k, then this can be accomplished only by rotating the cam s in such a way that the cam follower v rides along the rising portion .93 of the cam s until it reaches the portion 52 thereof.

As the cam follower v moves along the rising portion s3, its movement is resisted by the spring u. Consequently, the opening or placing into operation of the additional jet e or additional jets is also made clearly perceptible to the driver in that case by means of a point of resistance as soon as the cam follower v rides on the cam portion s3 and thereby tends to rotate clockwise, as viewed in Figure 2, against the action of the spring 11.

Moreover, the control arrangement according to the embodiment of Figure 2 offers the advantage that the resistance of the spring u is effective only during the passage of the cam follower v from its position along, the cam portion s1 to the cam portion s2, i. e., as it rides along the cam portion s3 when the cam is rotated in the clockwise direction, as viewed in Figure 2. Once the cam follower v reaches the cam portion s2, the effect of the additional stress in the spring u is not or practically not noticeable in the further operation of the control rod k. Consequently, ease in the operation of the controls is assured and weariness of the operators or drivers foot is obviated. Instead of being arranged on the throttle valve shaft r the cam s may also be arranged on the accelerator foot pedal. The constructional arrangements to provide the point of resistance and also for the opening of the jets may be made in any suitable manner.

It will be. obvious that the details of the construction according to my invention may be varied from those shown in the drawing. I, therefore, do not limit myself to the details as described herein and shown in the drawing except as defined by the appended claims.

What I claim is:

l. A control mechanism for carburetor type internal combustion engines comprising a single throttle, a control member actuatable to adjust the position of the throttle, at least two fuel jets, individual control means controlling the supply of fuel to said jets, means connecting a first one of said control means to said control member thereby to render a first one of said jets operative throughout the full range of adjustment of said throttle, means connecting another of said control means to said control member thereby to render another of said jets operative throughout only a portion of the said range defined by an intermediate position of the throttle corresponding to most economic fuel consumption and the fully open position of the throttle, and pre-tensioned resilient means perceptibly and yieldably opposing movement of said control member to actuate said throttle throughout the range of movement from said intermediate position to said fully open position.

2. A control mechanism for internal combustion engines comprising a carburetor having a single throttle, said carburetor being operative to provide most economical fuel consumption in a position intermediate the idling and full load positions thereof, linkage means connected to said throttle for adjusting the position thereof from an idling position to a full-load position, pre-tensioned resilient means co-operating with said linkage means to provide a definite predetermined force opposing adjustment of said throttle upon movement thereof in the direction from said idling position towards said full-load position at said intermediate position corresponding to the most economical fuel consumption and to thereby provide the driver with a clearly perceptible indication when said intermediate position is attained, a plurality of sequentially operable fuel supply valves, means connecting said valves to said linkage means for opening one of said valves throughout substantially the full range of adjustment of said linkage means and. for opening an additional one of said valves only in the limited range of adjustment of said linkage means substantially between said intermediate position and said full load position to thereby increase the fuel supply to said carburetor only after giving notice to the driver of passing said intermediate position.

References Cited in the file of this patent UNITED STATES PATENTS 1,120,185 Duff Dec. 8, 1914 2,043,514 Mennesson June 9, 1936 2,302,527 Coffey Nov. 17, 1942 2,313,366 Schwier Mar. 9, 1943 2,320,012 Rial] May 25, 1943 2,609,187 Scott Sept. 2, 1952

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