US2403865A - Supercharging control for internal-combustion engines - Google Patents

Description

July 9, 1946.* P. LEBE T SUBERCHARGING CONTROL FOR INTERNAL-COMBUSTION ENGINES Filed Mardh 1:5, 194s width or the main supercharging ports control slots. On the other hand the number Patented July 9, 1 946 CONTROL FOR IN TER- NAL-COMBUSTION ENGINES SUPERCHARGIN G Pierre Lebet, Arbon, Akticngcsellschaft A zerland A Switzerland, dolph Saurer,

r3 OFFICE assignor to Arbon, Swit- Application March-13, 1943, Serial No. 479,023 In Germany January 9, 1942' v 7 Claims. (Cl. 12375) This invention relates to internal. combustion engines provided with superchargingmeans.

It is an object of this invention to improve the supercharging ing any separate control mechanism.

Since the time interval required for the supereharging coincides with the compression stroke, this interval must be kept as short as possible, since otherwise the supercharging effect wouldbe impaired by the inevitable shortening of the effective compression stroke. Therefore a prerequisite for a satisfactory supercharging effect is the provision of large inlet portsin conjunction with high opening and closing speeds.

It hasalready beenproposed to provide supercharging ports in the cylinder wall which are controlled by a ring valve formed with corresponding slots, in order to obtain higher opening and closing speeds.

According to the present invention in engines of this latter type thecrossesectional area of passage of the supercharging. ports is increased considerably and.hiehopenin and closing speeds are obtained'without additional control members being required, by forming thatportion oi the; cylinder wall which adjoins the row at sunercharging ports and has not v.y tteen am by the working piston when the sup chargine period. is ended. with an addition l row of p rt controlled by additional slots in the ring valve, these additional ports and slots being however so. dimensioned, that during each stroke of the ring, valve whereby the first row of supercharging ports isuncovered, the additional ports are first uncovered and then covered again. In other Words, the circumferential width of the addi than the tional orts and slots. is made smaller and their of additional ports and slots and also their axial length may be greater than, the number and length of the main supercharging ports and their control slots.

In the drawing affixed to this specification and forming part thereof, an embodiment of the invention is illustrated diagrammatically by way of example.

In the drawing Fig. 1 is a section of the lower part ofthe combustion cylinder of an engine according to this invention.

Fig. 2 is a. section on the line IIII i rig. '1'

and

Figs. 3, 4 and 5 are cylinder deevlopments ilof the cylinders without addlustratine the different phases of the supercharg ing; period according to the invention.

Referring to the drawing and first to-Figs. 1 and 2, in the cylinder reciprocation is shown in its outer dead centre position, in which it, uncovers the scavengin ports 3 to which scavenging air is supplied throu h a conduit ,4. v

Above the scaven ing ports .3 a row f main superchargin p rts 5 and a s cond row or additional superchar ing ports '6 are provided. Compressed supercharging air is fed to these ports in a manner well known in the art. The ports 5 are arranged in that portion of the cylinder wall which isswept by the piston edge during the supercharging period, while the wall p01- tion, in which the ports 6 are formed, is not yet swept by the piston when the supercharging period, has come to an end.- The circumferential widthof the ports 5 6 than the width of. the. intervening wall portion The slots Ill and and the width of "the additional ports 6 is only about half that of themain'po'rts 5.

0n the other hand thehumber of additional ports 6 is. greater than the number of main ports 5. .Theicylinder .l is surrounded by a ring valve 8 which is formed with two rows of slots 10 and H which correspond in number, size and spacing to the ports 5 and 6, respectively, in the cylinder. I! are so staggered relative to circumferential direction, that the ring valve all port 5 and valve is oscillated by means of a driving lu 9 acted upon by a rod I 4 oprat ng a ainst the action of a spr ng 5 a d bein actuated by a cam shait IBQm unted for rotation in the engine fr me nd carry n m e s I! (Fig. 2).. The lug 9 is arranged on the ring valve 8 on the level of the interstice between the ports 5 that. are controlled by the piston and the p r s 6 hat are controlled exclusively by theslide valve, whereby the stress exerted by the lug 9 on the sleeve is appropriately distributed.

The stroke of the ring valve is greater than the width of the ports 5 by the amount required for closing said ports in a pressure-tight manner and on the other hand completely uncovering them. The additional ports 6 and each ther in the in one position of 6 re clos d- The wide as the ports 5 and therefor are completely I a piston 2 arranged for I is somewhat smaller working piston,

, to the compression Figs. 3 to 5 illustrate the relative positions of the working piston and the ring valve relative to the supercharging ports at three consecutive times, the ports 5 and 6 in the cylinder wall being schematically illustrated for different time moments. In thesefigures the slots 3, 5 and 6 in the cylinder wallare shown in full lines, while the slots Ni, ii in the valve ring are shown in dash lines. The contour of the portion of the cylinder wall swept by the piston are indicated by the chain-dotted line [2 and the hatched surface l3 respectively.

Fig. 3 illustrates the positionofthe parts at piston and the the end of the scavenging period.- Here the su-- percharging ports 5 and 6 are still covered by the ring valve and the piston moving away from the outer dead centre is on the verge oiclosing the. scavenging ports 3. Approximately at the same time the exhaust ports arranged at the upper end of the cylinder are closed by the valves 2|.

Fig. 4. illustrates the position of the parts in the middle of the supercharging period. The main ports 5 are half opened, the additional ports 6, beingnarrower, are open altogether. In the sec- 0nd half of the supercharging period the ring valve uncovers the ports 5 completely, whereas the narrower ports 6 are closed again.

Fig. 5 illustrates the condition existing at the end of the supercharging period. The ports 6 are closed by the ring valve, and the ports 5 are left open by the valve, but are covered by the working piston. As the working piston moves on, the compression stroke begins. After the additional ports 6 have been covered also by the the ring valve 8 is returned into its initial position shown in Fig. 3.

The mechanism above described as forming an object of the invention acts towardimproving' the supercharging of the cylinders-by increasing during the first part, for instance during the first half, of a normal supercharging period the crosssectional area of the passage admitting th supercharging medium into the cylinders.

I wish it to be understood that I do not desire V to be limited to the exact details shown and described, ior obvious modifications will occur. to a person skilled in the art.

I claim:

1. An internal combustion engine comprising in combination, a cylinder and a piston arranged for reciprocation therein, exhaust ports in said cylinder near the compression stroke end of said piston, exhaust valve for said ports,'a ring valve concentric with and contacting said cylinder, and two pairs of registering belts of intake ports arranged in axial alignment in said valve and in the part of the cylinder wall swept by said piston respectively, said pairs of parts being controlled by said ring valve, the ports in the belts nearer stroke end of said cylinder being materially narrower than the ports in the belts farther away from said cylinder end, and means for oscillating said ring valve.

2. An internal combustion engine comprising in combination, a combustion cylinder and a, piston'arranged for reciprocation therein, exhaust ports in said cylindernear the compression stroke end of said piston, exhaust valve for said ports, a ring valve concentric with and contacting said cylinder, and two pairs of registering belts of intake ports arranged in axial alignment in said valve and in the part of the cylinder wall swept by said piston, respectively, said pairs of ports being controlled by said ring valve, the ports in the belts nearer to the compression stroke end of said cylinder being materially narrower and of greater axial length than the ports in the belts farther from said cylinder end, and means for oscillating said ring valve.

3. An internal combustion engine comprising in combination, a combustion cylinder and a piston arranged for reciprocation therein, exhaust ports in said cylinder near the compression stroke end of said piston, exhaust valves for said ports, a ring valve concentric with ing said cylinder and two pairs of registering belts of intake ports arranged in axial alignmentin saidvalve and in the part of the cylinder wall sweptby said piston respectively, said pairs of ports being controlled by said ring valve, the ports the belts nearer to the compression stroke end of said cylinder being materially narrower and of greater axial length and more narrowly spaced than the ports in the belts farther from said cylinder end, and means for oscillating said .ring valve.

4. An internal combustion engine comprising in combination, a combustion cylinder and a piston arranged for reciprocation therein, exhaust ports in said cylinder near the compression stroke end of said piston, exhaust valve for said ports, a ring valve concentric with and contacting said cylinder and two pairs of registering belts of intake ports arranged in axial alignment in said valve and in the port of the cylinder wall swept by said piston respectively, said pairs of ports being controlled by said ring valve, the ports in the belts nearer to the compression stroke end of said cylinder being about half as wide and about double as long as the ports in the belts farther from said cylinder end, and means for oscillating said ring valve.

5. An internal combustion engine comprising in combination, a combustion cylinder and a piston arranged for reciprocation therein, exhaust ports in said cylinder near the compression stroke end of said piston, a belt of intake ports in the cylinder wall near the suction-stroke end of the cylinder and{ two additional belts of intake ports in the cylinder wall in axial alignment with said first belt, a ring valve concentric with and contacting the part ofsaid cylinder formed with said two additional belts of intake ports, said-valve being formed with two belts of ports registering with said additional cylinder ports, the intake ports in said cylinder and said valve which are next to the compression stroke end of said cylinder being narrower than the intake ports forming the axially adjoining belts and means for oscillating said ring valve.

6. An internal combustion engine comprising in combination, a cylinder and a piston arranged for reciprocation therein, exhaust ports in said cylinder near the compression stroke end of said piston, an oscillatory ring valve concentric with and contacting said cylinder and two pairs of registering belts of intake ports arranged in axialaligmnent' in said valve and in the part of the cylinder wall swept by said piston, respectively, the width of the ports in the belts nearer to the compression stroke end of said cylinder in the direction of the movement of the ring valve, being about one half of the width of the ports in dthe belts farther remote from said cylinder en '7. An internal combustion engine comprising in combination, a cylinder and a piston arranged for reciprocation therein, exhaust portsin said cylinder near the compression stroke end of said piston, an oscillatory ring valve concentric'with and contacting said cylinder and two pairs of registering belts of intake ports arranged in axial alignment in said valve and in the part of the cylinder wall swept by said piston, respectively, the width of the ports in the belts nearer to the compression stroke end of said cylinder in the direction of the movement of the'ring valve, being about one half of the width of the ports in the belts farther remote from said cylinder end, 1; e stroke of the ring valve being about equal to the width of the latter ports.

PIERRE LEBET.

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