US2120012A - Internal combustion engine - Google Patents

Description

June 7, 1938. J'. E. NDREAU INTERNAL COMBUSTION ENGINE.

2 sheets-sheet 2 Filed April l0, 1935 @im N f Patented June 7, 1938 UNITED STATESv PATENT OFFICE INTERNAL COMBUSTION ENGINE Application April 10,1935, serial No..15,651

nl Belgium April 14, 1934 11 Claims. (Cl. 123-48) .'Ihe present invention relates to internal combustion engines and also to vehicles, such as automobile vehicles (on road or on'rail) or aircrafts, provided with such engines.

q Up to the 'present time, enginesof this kind had, in a general Way, a cylinder capacity and a clearance space which were geometrically xed. It follows from this arrangement that the utilization of the gases admitted into the engine is' very bad for low loads.

The reason is that, for such loads, it is necessary to utilize a considerable portion of the 'compression stroke for restoring atmospheric pressure in the cylinder and that the true ratio of compression decreases more and more as the load decreases. v

'I'he consumption of fuel then increases, be-

coming as high as 700 or even 800 grammes per.

horse-power hour for the engines of motor-cars running at speeds ranging between 20. and 30 kms. -per ho'ur.

The object of the present invention is to -provide an engine o f the t'ype above referred tov in which the drawbacks above mentioned are obviated.,

The essential feature of 4the present-invention consists in providing an engine of the type above referred to` with means whereby theyolumetric ratio of compression 'is automatically varied within certain limits in such manner as to keep the true ratio of compression substantially constant under all conditions of working oi' the engine corresponding with these limits.

Other features of the present invention' will be apparent from the following detailed descripand its piston, serving to illustrate the principle of the present invention;

Fig. 2 is a diagrammatic Iaxial sectional view.

of the head of a cylinder made -according to the present invention;

Figs. 3 and 4 are views similar to Fig. 2, show? ing two other embodiments of the device according to the presentinvention;

Fig. 5 is a dlagrammatical view of a system including an engine and means for controlling.

said engine, the wholebeing devised \accordl .ing to the present invention,the view being in general a plan view but many of the parts being .desired value (for instance shown in section,` while the intake manifold is shown in elevation, for the sake' of clarity;

' Fig. 5a is a. fragmentary top view of the conf trol mechanism oi' the throttle valve 23 shown in Fig. 5.

Fig. 6` shows a modiilcation of the system of Fig. 5, this modiflcationfbeing more especially .intended for aircraft engines;

Let us rst consider a normal engine, as shown in Fig. 1, in which the piston I moves between an upper extreme position A and a lower extreme position Br while the plane O represents the lower face of the cylinder head. Let it be irst assumed that this engine is running under normal conditions (the throttle valve full opened). During the compression stroke, atmospheric pressure is established in the cylinder when the piston is at level B not very far from point B. The true ratio of compression is then This ratiofof compression may be, for instance, 8 to 1.

0n the contrary, when the engine is running 'with' the throttle valve closed or nearly closed, there is aconsiderable degree of vacuum in the intake pipe and, consequently, when the piston passes the position B during the compression stroke the pressure ol' the charge is even lower than atmospheric pressure. A supplementary piston travel B'B" is therefore necessary before atmospheric pressure is restored in the cylinder. In this caseI the true ratio of compression is equal to OBI! that is to say much lower than in the preceding case. It may even happen that the pressure in the cylinder at the end of the compression stroke islower than atmospheric pressure.

If, under the last mentioned conditions of running,l the cylinder head had been in position O', that is to say at a level lower than'- O, then the ratio of compression would have -been OIBII and therefore might have been made equal to the 6 to 1) by suitably .choosing position O'.

In such an engine, the effective cylinder cag pacity, would correspond to the stroke AIB", and, furthermore, in the course of the -expansion 70 p vided .for "keeping the cylinderhead applied` against said cam, or any other equivalent organ.v

. valve engines having a single sliding sleeve valve,

stroke, the piston of such an engine, instead of stopping at B", as would be the case with the piston oi' an ordinary engine of the same compression ratio, movesifuther down as vfary as the vicinity of B' (normal *exhaust opening). It follows that the ratio of expansion, and therefore the eillciency, is the higher asvtheicharge is smaller. I g

According to the present invention, an` internal combustion engine of any kind whatever,

for instance a multi-cylinder combustion engine for an automobile vehicle, is provided with means whereby the volumetric ratio of compression of said engine varies automatically within certain limits so as to maintain the true ratio of com- 'pression constant forv all conditions of illling of the engine cylinders corresponding with these limits, which are preferably wider apart than the limits of utilization.'

I have found that the desired result can be v obtained in a particularly advantageous manner Vby making the cylinder head of each `cylinder thelatter is guided by the cylinder, the cylinder head (or stationary piston) being entirely free to move.

In the following description, it will be assumed that the engine is of the sliding valve type with a single sliding sleeve valve 2.

Accordingto the embodiment shown yby Fig.

2, the cylinder head 3 of leach cylinder oi the engine is mounted in such manner, with respectto said cylinder, that it can be given trans- 'latory displacements parallel to the axis of said cylinder. Y

Said cylinder head l is provided with a screw threaded outer wall I, the threads being preferably irreversible, and on this partJ there is screweda nut 5 integral with a control lever 6.'

- This nut can begiven only 'rotary displacements owing to the provision of an upper stop;;1 and` a lower stop i, both carried by the upper part of the cylinder. v

It will be readily understood that, with such an arrangement, acting on lever l, nut i is caused to turn andconsequently'the cylinder head I is caused to move either upwardly or downwardly.`

In order wicooi said cylinder head, I advan-j.

tageously provide a cooling jacket communlcat ing with the water circulation of the engine, for

instance through screwed tubes I andv Il.

In the embodiment illustrated by Fig. 3, the

cylinder head is controlled by means of ;a. systemf *of wedges II which can l displacements. In the embodiment illustrated by 168.4; the cylinder head is actuated by means of a cam y I2. Springs II, lof suilcient lstrength,- are 'prowhen'the latter do not exert an operative action in .both directions.

order to engine proper mrd-- ing to the present invention, I provide means for controlling the position of the cylinder heads -in accordance with the loaii of the engine as indicated by the manifold suction. Assuming,A for instance, that the engine in- 5 cludes four cylinders (Fig. 5) and that the cylinder heads are controlled through a device of the kind shown by Fig. 2, the free ends of the respective levers 6 may be all operatively .con-- nected to a longitudinal control piece Il, springs 10 such as I5 and I6 being provided in connection with each arm. 6 as shown in the drawings. that isito say in a manner similar to the arrangement used in steering gears.

Owing to the presence of these springs, the

organ thatMacts on control member I4 shall not be required to displace the cylinder heads while the latter are subjected to the maximum lpressures of the cycles.

This is due to the fact that the cylinder heads 2o are subjected to the action of alternating forces and can therefore be caused to undergo elementary displacements nearly without` resistance during the favorable periods of the cycles. In

this manner, the displacement of the cylinder heads, which necessitates several cycles, if it is of a certain amplitude, takes place very easily.

I have found that it is advantageous, in order to move control member Il, to make use of a servo-motor I1, of any kind whatever. For instance, according to the embodiment of Fig. 5, this servo-motor includes a piston I8 which is subjected, on either of its faces according to the position of a slide valve I9, to the action of oil under pressure-fed either by a usual compres- 35 'sion pump, or, preferably, by an accumulator having an air cushion at the top, 20, in which aV pump 2i maintains, at anytime, a reserve of oil under4 pressure sufllcient for ensuring a certain number of complete strokes lof member 40 I4, for instance ten of these strokes.'

Thus, according as the slide valve I9 is displaced in one direction or in the opposite `direction, the volumetric ratio of compression of all' the cylinders of the engine will vary in one direc- 45,

tion or the opposite one.

It sumces, now, to establish for the control of said slide valve I9. a device such that the condition Aabove stated is complied with.

Theoretically, if the variations of load and 50 lspeed of the engine were sufficiently slow, it would ,suillce to control slide valve I9 through a manometric box subjectedto the suction existing in the intake pipe of the engine beyond the throttle valve, for obtaining the desired working, provided, of course, that the whole is deg-f" visedA in such manner that, at least within certain limits, to each value of this lsuction there corresponds, for the engine, a volumetric ratio of compression, itself corresponding to the de- .60

sired true ratio of compression.

' lBut every time 'the variations of load and speed of theengine must be quick, which is, for instance, the case with automobile vehicles, vit is necessary, in orderto avoid accidents as might result .iromexcessive ratios of compression (dus. for instance to the fact that, in the case of a sudden opening of the throttle valve, the cylinder heads would not move upwardly suiiiciently of fuel mixture to the 4engine (and which'will be; hereinafter called throttle pedal). This operative connection between the throttle pedal and V quickly), to submit. they-,cylinder heads to the 30 `action. of the organ that controls the admission the; cylinder heads is so devised that, in the l5.

-besides control member i4 and'servo-motor I1,

the intake pipe 22, its throttle valve 23, and also the throttle pedal 24. l

On pipe 22, beyond throttle valve 23, I pro-v vide a manometric box communicating with said pipe and including a. diaphragm '28.

I x to control member I4, on the one hand an element 21 adapted to limit the displacements of a lever 28 keyed on the spindle of the throttle valve in the direction that corresponds to the opening of said throttlev (so that the opening of 'resistance decreases, the suction increases, the

to reduce the torque.

said throttle can neverbe greater than that co'r- I throttle pedal can be moved in the direction corresponding to the opening of the vthrottle even when said throttle is prevented from opening at this time by the fact that lever 23 is in vcontact with nement 21.

This throttle isv further subjected to the action of a spring 35 tending to open it. Finally I interpose, between throttle pedal 24 and the free end of lever 3i, a connecting rod 3B 4-an intermediate point 31 of which, for instance ,its middle point. is operatively connected with diaphragm 2B. e

The systemy above described works inV the fol-h lowing manner:`

supposing, mst, that the'tnrbtue' pedal 1s actedv of the cylinder, heads. But, at the same time,-

pivot 3|) is moved through the action of the servo-y motor I1 in such manner as to bring .back slide valve I9 into its neutral position and the' servo,A

motor stops. @uring this time, the element V21 against which lever 23.was, applied also moves, thus permitting the throttle to open 4the desired amount. 'I'he engine therefore gives a` greater torque than before.

If now, on the contrary,'the throttle valve is'A acted upon in such manner as to close thethrottle valve, the operationsy above described take place in the reverse order, but in this case the throttle valve' is closed directly by the. throttle pedal and the rate of feed is immediately re'- duced. The displacement of the cylinder heads diaphragm of box 25 'acts on point 31, so as to produce a reduction of ther clearance spaces and The vmovement of control member I4 produces, through the displacement ,of pivot 30, the return of slide valve I9 to its neutral position, at the same time as element 21 reduces the opening of-the throttle valve to the i proper degree. y

' An equilibrium is thus established which corresponds to a lower rate of feed and the automatic regulation of the capacity of the cylinders and of the turques is obtained.

In the preceding description I have been referring to the case of internal combustion engines. The invention is of course applicable to any type of such engines, provided that they include a simultaneous control of air and fuel. Thus these engines will no longer require the pumping o f air which is necessary at the present time under low loads. This pumping reduced the emciency and prevented the fuel from being utilized under the optimum conditions.

When applied to aircraft engines, the present invention makes it possible to obtain a `better A'utilization of the fuel at all altitudes.

low speeds. It is thus possible to wholly dispense with a change speed device and to have awhollly autostationary.

It suillces, in this case, in order to obtain the desired eect, to complete the mechanism shown by Fig. 5 by adding thereto a manometric box 39 (Fig. 6) the diaphragm of which is mechanically connected with point 31 and inside which the pressure is equal to the atmospheric pressure on the ground level.

This box then dilates more and more as the external pressure decreases and actsin. the same manner as' an increase of the suction in the intake pipe of the engine, that is to Asayreduces the clearance spaces and restores the normal pressure .of explosion. e

`This solution isbelieved to be superior tothe usual constantunder-feed or to the provisionl of compressors.

When devising an automobile vehicle according to the present invention, it will be preferable to interpose, lbetween the engine and the driving' wheels an automatic clutch 33, for instance of the hydraulic type, capable of transmitting the maximum torque of the engine when the vehicleis I may, for this purpose, make.. use of a clutch such as those called fluid y-wheeis", which lensure a.- nearly complete release' at very matic control of the vehicle, 'since the: driver is concerned merely with the throttle pedal (or the equivalent) and the brake.

According to 'the present invention, an auto'- mobilevehicle provided with an engine such as that above described may be streamlined .fin such .manneras to reduce the head resistance.

As a matter .of fact, one of the most characteristic drawbacks o f streamlined bodies for automobile vehicles is'tthat said vehicles are nearly always running (except for the maximum speed corresponding to the'maximum power of their is then facilitated by the action of diaphragm engine) withv a power substantially lower than said maximum power.` "Thus, with an ordinary engine,- the specific consumption is not so good, for a giv'en speed, v"

than if the vehicle were. not streamlined. since the throttlevalve is less'opened and therefore the true ratio of compression. is lower. Therefore, due to the fact that the fuel is not so wellutilized. a portion of the benefit obtained by the reduction of the power necessary iorl propelling the vehicle is lost.

' On the contrary, with an engine according to the present invention, as the specific consumption is not inuenced ina detrimental manner by thel reduction of the load, it is possibleto obtain the maximum benet of the advantages of streamlined bodies and the consumption of fuel will remain very low at all speeds. Y.

Ina general manner, while I have, in the above description, disclosed what I deem to be practical movablein one direction for enlarging the comand eillcient embodiments of the present invention, it should be well understood that I do not wish to be. limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within thescopeof the accompanying claims.

what Iclaim is:

1. An internal combustion engine comprising means forming a compression chamber the size of: which is capable of`being changed, a power Apiston movable in sai@ chamber. a valve for feed- Aing -fuel to said chamber, means for eifecting a change in the size of said chamber and for operating said valve when the size of the chamber has been changed, means for delaying the motion of said changing means and a one-way connection between said changing means and said valve, whereby said changing means will operate said valve directly only when'said changing means move in one d ection.

2. An internall com ustion engine comprising.

means forming a compression chamber, a piston movable in said chamber, regulating means for varying the size of said chamber and including va member movable in said chamber, a valve for feeding a fuel mixture to said engine, and actuating means connected to said regulating means and pression chamber and in the opposite direction for reducing.thesame, means connecting said actuating means to -said valve and comprising a one-way connection-for moving said valve toward openv position when the compression chamber is enlarged and for engaging the valve with said connecting means for moving the same toward A closed position when the compressicn'fchamber is reduced.

3, In an internal combustion engine according to claim 2, having an intake manifold, means connected to said manifold and said'resulating means li'or automatically controlling said regulating means and said valve, said control means be-,. ing under the influence of and operated by varia-A tions'in the degree of vacuum in said manifold.

-4. A n internal combustion engine according to claim 2, means for automatically adjusting said regulating means and said valve, said means being under control oi' the pressure of the outer atmosphare Afor adjusting thesize of said compression chamber andadjusting said valve in accordance with variations of said pressure.

5. An'internal combustion engine according to,

claim 2 having an intake manifold, said actuating means comprising an element i'or automatically "controlling said regulating means and said valve.

A said element being under the innuence of and ing lsaid regulatingmeans and*y operated by variations in the degree .of vacuum in said manifold-means for. automatically adjust-- d valve. said adjusting means being under control of the pressure oi' the outer atmosphere for the size of said compression chamber and adjusting said valve in accordance with variations of saidpressure.

6. An internal combustion-engine according to claim 2, further comprising resilient means connecting said movable member to said regulating means for delayingv the movement of said member in said compression chamber when the pressure withinv said chamber exceeds a certainlim-it.

7. An internal combustion engine comprising means forming 'a compression chamber, a piston movable with a vreciprocating motion in said chamber, regulating means for adjusting the size of' said compression chamber and including a member movable in said chamber, a 'valve for feeding fuel mixture to said engine, and actuating means connected to said regulating means and movable in one direction for enlarging said compressionl chamber and in opposite direction for reducing the size of said4 chamber, means integrally connected with said regulating means for controlling the degree of opening of said valve, means connected to said valve for normally holding the same in opened position and in contact with said control means, said valve being independent of the movement of said actuating means -tor enlarging the compression chamber, and

means independent of the movement of said regulating and control means, for operatively connecting said valve to said actuating means during said reducing movement.

8. In an internal combustion engine according tovclaim 7, said independent means comprising an element slidably arranged with respect to said valve and being secured to said actuating means, whereby, at the movement of said actuating means for enlarging the compression chamber,

said element slides with respect to said valve said stop immediately moves said valve toward a closing position.,l

10. An internal combustion engine according to claim 2', said regulating means including la system of levers and a servo-motor including a slide valve connected to said levers, whereby upon movement of said actuating means, said slide -valve is returned to a neutral position'- as soon as the compression chamber has been adjusted to 'the desired extent.

11. An internal combustion engine having for adjusting the size of said chamber, said means comprising a servo-motor, a member actuated by said servo-motor, a mechanism ,operatively connected with said chamber for varyingv the size thereof, and lresilient means interposed lbetween said mechanismL and said member connecting the same vfor delaying the varying movement of said mechanism when the pressure within "said combustion chamber exceeds a certain limit,

said resilient means being Aoperative in both directions of movement of said adjusting means.

JEAN EDOUARD ANDREAU.

'means forming a compression chamber, means

Images