US2113101A - Combustion chamber - Google Patents

Description

April 5, 1938. 1 F, WHITE 2,113,101

COMBUSTION CHAMBER I Filed June 4, 1957 INVENTOR. f .fmes ,Qn/#6 E E- BY ATTORNEY.

Patented Apr. 1938 UNITED STATE s PATENT oFFlcE f A cormUsTroN grumman. James F. White/Amarillo, Tex. applicati@ June 4, 1937, sei-m No. 146,435

s (c1. 12s-191) 'I'his invention relates to combustion chambers of internal combustion engines.

The main object 'of my invention is the provision of means for controlling combustion in 5 internal combustion engines in such manner that higher compression pressures may be used than formerly and in such manner that maximum pressure is carried beyond the point in regard to the crank angle that is possibleA with the combustion chambers heretofore used.

The basic cause of detonation, ping or spark knock, is the lack of available expansion space in the combustion chamber. pressure and resultanttemperature is reached, blanket ignition takes place. In other words, if you had a combustion chamber or clearance space having a total capacity of 60 c. c., when the piston is at top center orpoint of highest compression pressure and the fuel charge contained therein were ignited by means of the common spark plug or other suitable means under a pressure of 180 poundsper square inch the following would take place in the standard form of automobile engine now in use:

AStarting with the 180 lbs. pressure at time of ignition, the pressure will rise. in direct pr0. portion to the amount of fuel burned. This rise is subject to be modiiied by the rate of increase of available expansion space. The rate of increase of available expansion space is a question of crankshaft and piston speed, which is variable. The-rate .at which fuel will burn, under a given pressure, is a nxed thing, only variable with the temperature and other causes to a small degree.

The rate of burn and the resultant pressure rise are so fast that, except in extreme engine speeds, by the time 45 to 50 c. c., of fuel have been burned, a pressure will be obtained .high enough to produce blanket ignition and the remaining to,15 c. c. of fuel will burn all at once, explode as it were. This latter fuel is .thus wasted, because the piston is not giving way fast enough to provide expansion space for a pressure rise so sharp.

' In order to prevent this explosion and waste, the pressure rise must be kept down or'in some way it must be reconciled to the piston speed. Therefore one of the objects of this invention 50 is to provide means for preventing such an explosion and waste.

I propose to bring about this improvement by dividing the combustion chamber into two portions or parts. separating the two parts, so far as ignition is concerned, by using a part When a certain of the piston head and apart of the combustion chamber ceiling or roof, and shaping and mating them in such manner as to form a quench wall or barrier to ignition therebetween which will be maintained until the crankshaft is well 5 past top center and the resulting piston speed provides a much higher rate of increase in available expansion space. w v

The value of the above can be shown by making this comparison. If one had a compression 10 ratio that would give a compression pressure of 200 lbs. per square inch at which pressure the fuel were ignited, and supposing that the burning fuel gives a pressure rise of 20 lbs. per degree of crank angle -for the ilrst 20 degrees, the result would be a 400 1b. increase. This would make a total of 600 lbs. which would be certain to produce detonation.

On the other hand, if one were to take the same volume under the same pressure and divide it so that the ilrst portion of the fuel to burn will generate 10 lbs. pressure rise per degree of crankangle for the nrst 20 degrees, the result .would be a total of 400 lbs. which would not produce detonation, and if, at or near this point, the remaining portion of the fluid were ignited under 400 lbs. pressure, the resulting very fast rate of burn and pressure rise will be turned into crank eifort instead of being wasted, vbecause the piston speed, at the latter point,l is fast enough to provide expansion space rapidly 'enough to keep the maximum pressure well under the detonating point.

In the accompanying drawing:

Fig. 1 is a sectional elevation of the upper end-of the cylinder of an internal combustion engine embodying my invention on the line -l Fig. 2, the piston, inlet valve and 'spark plug being shown in full except that the iirst is broken away to show the relative construction of the cylinder head and piston at the section line;

Fig. 2 is a section on the line 2-2 Pig. l.

I is the cylinder; 2, the intake valve; 3, the spark plug and l, the piston shown as at the upper vend of its stroke.

5 isthe cylinder head so formed as to'afiord the intake passage l and the compression ch'amber 1, when in place.

The lower surface of the cylinder head i is in the plane of the upper edge of the cylinder and at the right where it borders the explosion chamber 1 it is circular in form concentric with the cylinder bore as indicated by the broken line in Fig. 2. At the left of the diameter, the cylinder head presents a wall 0-8-4. the lower 55 cally to an appreciable extent.

The piston 4 has a projection 4a rising from its upper end'and ilttingin close proximity to the inner surface of 8a of the wall s so that the intake passage is thereby separated from the combustion chamber by this quench-wall until the upper edge of the projection 4a passes beneath the lower surface of the wall 8 a distance sufilcient tov permit flame penetration into combustion chamber 1.

The operation of the above described construction is as follows:

The charge is compressed into the combustion chamber and valve passage by therising piston and at the upper end of the piston stroke the portion of the charge in the intake passage is ignited. The piston then descends until the upper edge of the projection la comes below the lower surface of the wall 8a a sumcient distance to permit flame penetration into combustion chamber 1 at which point the crank has reached a considerable angle on its down, or working, stroke. The portion of the charge in the. intake valve passage i previously has risen to a very high temperature and pressure because of its compression and because of the burning gases therein, and now is admitted to the combustion chamber 1, progressively igniting the charge therein,

which causes 'further rise of the temperature and pressure. This consequent rise in pressure thus takes place when the crank is at a more advantageous working angle.

What I claim is: u

1. In an internal combustion engine, a cylinder having a combustion chamber, an ignition means in a portion of said chamber, and means on the ceiling of said combustion chamber cooperating with means on said piston to separate said portion from the rest of the combustion chamber and to effectively prevent flame propagation therein during the early portion of the working stroke.

2. In an internal combustion engine, a cylinder having a combustion chamber and an intake passage and an ignition means in said passage, and means on the ceiling of said combustion chamber cooperatingA with means on said piston to separate said intake passage from saidcombustion chamber and to effectively prevent flame propagation therein during the early portion of the working stroke.

3. In an internal combustion engine, a combustion chamber having a wall having a substantially vertical surface dividing the same into two portions, an ignition means in one of said portions, a piston having a wall having a substantially vertical surface, said walls being so formed andlocated that said surfaces shall move into close proximity to each other to form a quench wall at the upper end of the piston stroke.

4. In an internal combustion engine, a comlbustion chamber, an intake passage, said coma,ns,1o1 y A bustionchamberhavingawall withasubstantially vertical surface separating the 'same from saidintake passage, an ignition means in said passagc.andapistonhavingawallwithasub stantially vertical surface, said wallsbeing so formed and located that said surfaces shall move into close proximity to each other to form a quench wall at the upper end of the piston stroke and separate said combustion chamber from said intake passage.

5. In an internal combustion engine, a combustion chamber, said combustion chamber having means for dividing it substantially into two chambers when the piston is at the upper end of its stroke. an ignition means in one chamber and none in the other, said dividing means comprising a quench wallformed by a portion of. the combustion chainber ceiling and a portion` of the piston, said quench wall having a suillcient clearance between the portions forming it to eliminate surface contact and insumcient to permit flame penetration from one chamber to the other.

6. In an internal combustion engine, a cylinder, a combustion chamber in the upper end of said cylinder, a piston in the bore of said cylinder, a valve passage at one side of said cylinder, a wall having a vertical surface extending as a chord to the bore of said cylinder, and between said combustion chamber and valve passage, said piston having an upward projectionA having a surface adapted to coact with said wall surface in forming a ilame penetration barrier effectively separating said combustion chamber and valve passage for aI short distance at the upper end of the piston stroke.

7. In an internal combustion engine, a cornbustion chamber having a wallhaving a substantially vertical surface dividing the same into two chambers, an ignition means in one of said chambers, a piston having a wall having a substantially vertical surface, said walls being so formed and located that said surfaces shall move into close proximity with each other at the upper end of the piston stroke, so as to form a quench wall that will effectively prevent flame penetration from the first chamber to the second chamber, said surfaces having a clearance therebetween thatremains substantially Vconstant. until the piston has moved downward to a point where said vertical surfaces are no longer opposite each other.

8. In an internal combustion engine, a combustion chamberrhaving a wall having a substantially vertical surface dividing the same into two portions, an ignition means in one of said portions, a piston having a wall having a substantially vertical surface, said walls being so formed and located that-said vertical surfaces shall be substantially parallel to each other with suillcient clearance between said vertical surfaces i to 'eliminate actual contact of said vertical surfaces ing substantially constanttuntil said piston has moved downward to a point where said vertical surfaces are no longer opposite each other.

. JAMES F. WHITE.

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