US2303317A - Engine control mechanism - Google Patents

Description

Dec. 1, 1942. D. M. BERGES ENGINE CONTROL MECHANISM lllllllflll r/II Filed Jan. 17, 1941 71451!!! Il a!!! mvamon. 'Dona/d 5 yes NEY.

Patented Dec; 1,

ENGINE coN'raoL MECHANISM Donald M. Borges, Alpine, N. 1., assignor to Bendix Aviation Corp ration, South Bend, 1116., a corporation of Delaware Application January 17, 1941, Serial No. 374,924

1 Claim. (01. 123-108) This invention relates to internal combustion engines, and particularly to the control of the power developed by such an engine.

It is well understood that the throttle setting of an aircraft propelling internal combustion engine must be varied at frequent intervals during the flight of a craft, because of changes in the conditions which the craft encounters. Changes in altitude, for example, or in the-angle of flight, impose new load conditions upon the propeller or propellers of a craft, and there is a consequent necessity for shifting the engine throttle (to supply a larger or smaller quantity of fuel, as the conditions may require) if the developed power of the engine is to be held constant.

I am aware of the existence of devices and systems for automatic regulation of throttle setting; but there is disclosed herein a novel system of throttle regulation which (as will appear more clearly as the description of the invention proceeds) possesses certain definite advantages over those of the prior art. Thus, for example, instead of connecting the control mechanism to the intake manifold, as is done with many of the prior art devices, the present invention involves taking advantage of the torque measuring appliance that is now a standard engine accessory, and providing throttle regulating means operating in parallel relationship to said torque measuring mechanism. Since the torque develever, that the drawing is for the purpose of iilustration only, and is not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawing, I

Fig. 1 is a view, partly diagrammatic andpartly in mechanical section, of a system embodying the invention; and 1 Fig. 2 is a sectional view of a modified form of valve controlling cylinder.

In Fig. 1 there is shown diagrammatically, at

' 9, an internal combustion engine whose developed torque is measured by the customary torquemeter ID; the engine 9 having a throttle ll oped is in direct proportion-to fuel supplied, it

will be seen that a fuel regulating mechanism which functions directly in response to torque conditions, as measured on a torque-meter, will be just as accurate as one that involves tapping into the intake manifold. Moreover, the elimination of the need for physical contact with the intake manifold is a distinct advantage. In fact, for some time engineers have sought to obtain some means for getting automatic throttle regulation independently of tapping into the intake manifold, and therefore thepresent disclosure will be of definite utility in pointing out a new mode of achieving this objective.

Objects of the invention, therefore, are to provide a novel method of fuel regulation and an improved fuel regulating mechanism forintemal combustion engines, the advantages of which method and mechanism are pointed out herein, to a certain extent, but include others which will suggest themselves to those skilled in the art, after examinationv of the accompanying drawing illustrating one embodiment of the invention described herein. It is to be understood, howcated in the intake manifold H, a manual control lever l3 for the throttle, and a linkage l4, l5, and I6 connecting said lever and'throttle. The link extends above and below the link 14 and at one end receives a pin for pivotal connection with a rod-l1 constituting part of the novel throttle regulating mechanism now to be described.

The supply line 2| (leading from source l8 by way' of one-way valve l9 in line connects the torque meter ID with the cylinder 22 (in which is located the engine-controlled piston 23 whose movement reflects the torque conditions, in the manner known in the art); and from said line 2| I propose to install a tap-oil line 26, at the end of which line there is a cylinder 21 containing a piston 28, a spring 29, and a rod 3011f sufficient length to control flow of liquid, 'under pressure, to and from opposite chambers 33 and 34 of the servo-motor having a cylinder 36 containing a piston 31 in which the rod I1 is secured. To effect such control the rod is supplied with valve elements 4| and 42 having fluidtight, sliding relationship to a valve cylinder 43 from which lead the conduits 44, 45, 46, 41 and 48. 'Conduit 45 leads from a source of liquid under pressure, as for example, the engine oil pump; conduits 44 and-46 lead back to the oil sump or other pressure outlet; and conduits 41 and 48 lead to chambers 33 and 34 respectively.

With the foregoing arrangement it will be seen that as long as the developed torque is unchanged, valve rod 30 will not move from its setting as shown; the liquid pressure in the meter line being just balanced by the pressure of spring 29. In the setting shown ports 41 and 48 are both covered, hence there can be no fluid movement in cylinder 36 and therefore no movement of 'rod .l! or of the throttle linkage (except, of course, that manual intervention can cause the link ii to swing, at any time, about its pivotal connection with rod I 1).. Now in the event of a change in developed torque, for any reason, the corresponding change in the reaction upon stationary annulus gear 5| (of the conventional torque measuring mechanism) will create a change in pressure in cylinder 22 corresponding to the increase or decrease in developed torque; and this pressure change (as indicated on meter l) will create an unbalance in cylinder 21, which unbalance willmove valve rod 30 to allow liquid to flow from one chamber of cylinder 36, and a corresponding amount into the opposite chamber. The resulting movement of rod I! will shift link l about its central pivot 25 and thus change the setting of throttle The ensuing rise or fall in the developed torque (depending on the direction of throttle movement) will restore equilibrium and the ports 41 and 48 will again be covered, thus bringing movement of the piston 31 to an end. The throttle II will accordingly remain in the new position, assuring maintenance of the desired constant torque development by the engine, until such time as oocurrence of some new condition necessitates a readjustment, at which time the above-described cycle of action will be repeated.

The spring 29 is actually in abutment with a spring adjusting member 3| (Fig. 2) rather than the end wall of the cylinder 21; the purpose being to afford the aircraft pilot with means for selecting the desired value of torque to be maintained, it being understood that the amount of pre-compression of the spring 29 (by screw 3|) will control the pressure at which the valves ll, 42 are balanced, and hence the torque intended to be developed (and held constant) by the engine. As shown in Fig. 2, there is a pulley 32 integrated with screw 3|, and about this pulley there is wrapped a cable 33 leading to the cockpit of the craft, to aflord the pilot with a more convenient means of adjusting the position of screw 3| and hence the degree of compression of the spring 29. Source l8, I9, 20 is the source of fluid for operation of the elements (23, I0, 21) connected to line 2|. Fluid flows from It! to 2|, by way of IS and 20, whenever there is a vacuum, complete or partial, in said line 2| or the chambers connected therewith.

What is claimed is:

An automatic torque regulator for an engine having an adjustable fuel control comprising a reversible hydraulic piston operatively connected with said fuel control, a housing for said piston and two conduits leading thereto, a second piston responsive to the torque developed by said engine, a single valve mechanically connected to said second piston to move therewith, a housing for said second piston, said housing including a rotatable closure plate, and means responsive to rotation of said closure plate to vary the torque value maintained constant by said automatic torque regulator.

DONALD M. BERGES.

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