US3875909A — Process and apparatus for scavenging the swirl co…

Claim 1

Independent Claim 316 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine having at least one cylinder including a working chamber, a swirl combustion chamber, a flow aperture through which the swirl combustion chamber communicates with the working chamber, a single reciprocating piston, and at least one gas inlet port and at least one exhaust port in communication with the working chamber which are free of any valve control, the process comprising: a. forming the flow aperture to include a plurality of partial regions laterally adjacent each other and at least one upstream edge section; b. forming the at least one inlet port and the at least one exhaust port in the cylinder wall in the vicinity of the bottom dead center of the piston so that they are opened only when the piston is in its bottom dead center, c. establishing a main scavenging stream within the working chamber from a gas entering the working chamber through the at least one gas inlet port when the piston is at its bottom dead center; and d. splitting-off a portion of the main scavenging stream also when the piston is at its bottom dead center and as a result of the main scavenging stream contacting said at least one upstream edge section to thereby effect redirection of said split-off portion of the main scavenging stream through one of said plurality of partial regions and into the swirl combustion chamber, said redirected split-off portion of the main scavenging stream effecting a reverse, cross scavenging according to which said split-off portion is laterally displaced with the flow aperture so that the exhaust gases stream out of the swirl combustion chamber alongside of said incoming split-off portion and through another one of said plurality of partial regions to thereafter combine with the main scavenging stream flowing within the working chamber toward the at least one exhaust port.

Claim 2

Dependent Claim 316 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine having at least one cylinder including a working chamber, a swirl combustion chamber, a flow aperture through which the swirl combustion chamber communicates with the working chamber, a single reciprocating piston, and at least one gas inlet port and at least one exhaust port in communication with the working chamber which are free of any valve control, the process comprising: a. forming the flow aperture to include a plurality of partial regions laterally adjacent each other and at least one upstream edge section; b. forming the at least one inlet port and the at least one exhaust port in the cylinder wall in the vicinity of the bottom dead center of the piston so that they are opened only when the piston is in its bottom dead center, c. establishing a main scavenging stream within the working chamber from a gas entering the working chamber through the at least one gas inlet port when the piston is at its bottom dead center; and d. splitting-off a portion of the main scavenging stream also when the piston is at its bottom dead center and as a result of the main scavenging stream contacting said at least one upstream edge section to thereby effect redirection of said split-off portion of the main scavenging stream through one of said plurality of partial regions and into the swirl combustion chamber, said redirected split-off portion of the main scavenging stream effecting a reverse, cross scavenging according to which said split-off portion is laterally displaced with the flow aperture so that the exhaust gases stream out of the swirl combustion chamber alongside of said incoming split-off portion and through another one of said plurality of partial regions to thereafter combine with the main scavenging stream flowing within the working chamber toward the at least one exhaust port.

Claim 3

Dependent Claim 78 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine as defined in claim 1, wherein said plurality of partial regions is formed to include at least one lateral region, and wherein said split-off portion is redirected through said lateral partial region so that it traverses a loop-like path within the swirl combustion chamber, said redirected stream having a single axial component in the direction of the axis of curvature of the path.

Claim 4

Dependent Claim 83 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine as defined in claim 1, wherein said plurality of partial regions is formed to include a middle region, and wherein said split-off portion is redirected through said middle region so that it traverses a loop-like path within the swirl combustion chamber, said redirected stream having two opposite axial components thereby displacing the exhaust gases to either side of said middle region and out of the swirl combustion chamber.

Claim 5

Dependent Claim 36 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine as defined in claim 1, wherein the exhaust gases stream out of the swirl combustion chamber separated from the split-off portion.

Claim 6

Dependent Claim 77 words

A process for scavenging a swirl combustion chamber of a two-stroke cycle internal combustion engine as defined in claim 1, wherein said plurality of partial regions is formed to include at least one primary partial region and at least one secondary partial region, and wherein said split-off portion is redirected through said at least one primary partial region and the exhaust gases stream out of the swirl combustion chamber through said at least one secondary partial region.

Claim 7

Dependent Claim 292 words

In a two-stroke cycle internal combustion engine having at least one cylinder provided with at least one inlet port and at least one exhaust port which are free of any valve control, a cylinder head, a piston, a working chamber defined by the cylinder, the piston and the cylinder head, a swirl combustion chamber, and a flow aperture providing communication between the working chamber and the swirl combustion chamber, the improvement wherein the at least one inlet port and the at least one exhaust port are located in the cylinder so that they are opened when the piston is at its bottom dead center, and wherein said flow aperture is constructed to include at least one primary partial region and at least one secondary partial region, said regions being constructed and disposed relative to each other in such a way that said at least one secondary partial region presents a lesser resistance to the movement of gas out of rather than into the swirl combustion chamber, as a result during scavenging of the cylinder a main gas stream within the cylinder upon reaching said flow aperture has a portion thereof split-off at an acute angle to the direction of said main stream and streams at least substantially into the swirl combustion chamber through said at least one primary partial region, said at least one secondary partial region being disposed, when viewed in the direction of said main gas stream, laterally to said at least one primary partial region, said at least one secondary partial region serving to guide the gas leaving the swirl combustion chamber so that it attaches itself to said main gas stream with substantially no deviation and moves therewith in the direction toward the at least one outlet port.

Claim 8

Dependent Claim 292 words

In a two-stroke cycle internal combustion engine having at least one cylinder provided with at least one inlet port and at least one exhaust port which are free of any valve control, a cylinder head, a piston, a working chamber defined by the cylinder, the piston and the cylinder head, a swirl combustion chamber, and a flow aperture providing communication between the working chamber and the swirl combustion chamber, the improvement wherein the at least one inlet port and the at least one exhaust port are located in the cylinder so that they are opened when the piston is at its bottom dead center, and wherein said flow aperture is constructed to include at least one primary partial region and at least one secondary partial region, said regions being constructed and disposed relative to each other in such a way that said at least one secondary partial region presents a lesser resistance to the movement of gas out of rather than into the swirl combustion chamber, as a result during scavenging of the cylinder a main gas stream within the cylinder upon reaching said flow aperture has a portion thereof split-off at an acute angle to the direction of said main stream and streams at least substantially into the swirl combustion chamber through said at least one primary partial region, said at least one secondary partial region being disposed, when viewed in the direction of said main gas stream, laterally to said at least one primary partial region, said at least one secondary partial region serving to guide the gas leaving the swirl combustion chamber so that it attaches itself to said main gas stream with substantially no deviation and moves therewith in the direction toward the at least one outlet port.

Claim 9

Dependent Claim 78 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is defined by an edge section having edge sectors which are located both upstream and downstream, with reference to said main stream passing through said flow aperture, said edge section being associated with said primary and secondary partial regions, with those edge sectors associated with said primary partial region having a different construction than those edge sectors associated with said secondary partial region.

Claim 10

Dependent Claim 103 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is defined by an edge section, the upstream portion of which, with reference to said main stream passing through said flow aperture, is equipped with staggered portions for the gas which streams into the swirl combustion chamber and the gas which streams out of the swirl combustion chamber, and wherein said staggered portions are associated with said primary and secondary partial regions, with those staggered portions associated with said primary partial region being further from the working chamber than those staggered portions associated with said secondary partial region.

Claim 11

Dependent Claim 47 words

A two-stroke cycle internal combustion engine as defined in claim 8, wherein those staggered portions associated with said secondary partial region include at least one partial sector which is located at the level of the orifice which lies in the direction of the top of the piston.

Claim 12

Dependent Claim 21 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture contains a single secondary partial region.

Claim 13

Dependent Claim 44 words

A two-stroke cycle internal combustion engine as defined in claim 10, wherein approximately one-half of the flow aperture is constructed as a gas inlet for the swirl combustion chamber and the other half is constructed as a gas outlet for the swirl combustion chamber.

Claim 14

Dependent Claim 56 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is constructed to include a middle region and two further regions with one on each side of said middle region, said middle region being constructed as a primary partial region and said two further regions being constructed as secondary partial regions.

Claim 15

Dependent Claim 76 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is defined by an edge section including convexly curved sections associated with said primary and secondary partial regions which are located downstream, with reference to said main stream passing through said flow aperture, said convexly curved sections associated with said secondary partial region having a substantially larger radius of curvature than said convexly curved sections associated with said primary partial region.

Claim 16

Dependent Claim 93 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is defined by an edge section which includes staggered portions associated with said primary and secondary partial regions and has associated therewith a guiding surface leading to said staggered portions, said guiding surface being inclined at an angle with respect to a plane normal to the longitudinal axis of the cylinder and being located upstream, with reference to said main stream passing through said flow aperture, with respect to said staggered portion associated with said primary partial region.

Claim 17

Dependent Claim 38 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the cross section of said flow aperture has an elongated form defining a longitudinal axis which is inclined to the longitudinal axis of said outlet port.

Claim 18

Dependent Claim 59 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the working chamber includes two gas inlet ports and one gas outlet port, and wherein said gas inlet ports and said gas outlet port are symmetrical with respect to a symmetry plane containing the longitudinal axis of the working chamber, said symmetry plane intersecting said flow aperture.

Claim 19

Dependent Claim 24 words

A two-stroke cycle internal combustion engine as defined in claim 16, wherein said symmetry plane intersects said flow aperture approximately through the center thereof.

Claim 20

Dependent Claim 57 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the working chamber includes two gas inlet ports and two gas outlet ports, and wherein said gas inlet ports and outlet ports are symmetrical with respect to a symmetry plane containing the longitudinal axis of the working chamber, said symmetry plane intersecting said flow aperture.

Claim 21

Dependent Claim 24 words

A two-stroke cycle internal combustion engine as defined in claim 18, wherein said symmetry plane intersects said flow aperture approximately through the center thereof.

Claim 22

Dependent Claim 32 words

A two-stroke cycle internal combustion engine as defined in claim 15, wherein said symmetry plane extends approximately through the center of said at least one primary partial region of said flow aperture.

Claim 23

Dependent Claim 49 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the middle of said flow aperture is displaced from the longitudinal axis of the working chamber and is located in that half of the cylinder which contains said at least one outlet port of the working chamber.

Claim 24

Dependent Claim 34 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is formed as a single penetration connecting the working chamber with the inside space of the swirl combustion chamber.

Claim 25

Dependent Claim 23 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture is formed as at least two displaced penetrations.

Claim 26

Dependent Claim 29 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the height of said flow aperture is substantially less than the height of the swirl combustion chamber.

Claim 27

Dependent Claim 23 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the entire flow aperture lies above the top of the piston.

Claim 28

Dependent Claim 27 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the swirl combustion chamber is at least substantially located above the top of the piston.

Claim 29

Dependent Claim 38 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the volume of the swirl combustion chamber is approximately 40 to 90% of the volume of the cylinder when the piston is at its top-dead-center position.

Claim 30

Dependent Claim 38 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the volume of the swirl combustion chamber is preferably 60 to 90% of the volume of the cylinder when the piston is at its top-dead-center position.

Claim 31

Dependent Claim 38 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the volume of the swirl combustion chamber is preferably 80 to 90% of the volume of the cylinder when the piston is at its top-dead-center position.

Claim 32

Dependent Claim 36 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the smallest open cross section of said flow aperture is approximately 20 to 95% of the maximum cross section of the swirl combustion chamber.

Claim 33

Dependent Claim 36 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the smallest open cross section of said flow aperture is preferably 40 to 90% of the maximum cross section of the swirl combustion chamber.

Claim 34

Dependent Claim 36 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the smallest open cross section of said flow aperture is preferably 60 to 80% of the maximum cross section of the swirl combustion chamber.

Claim 35

Dependent Claim 77 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture includes an edge region part of which is assigned to said primary partial region, said assigned edge region, being that region where said split-off portion is generated, having a channel-shaped bay area surface associated therewith, with said channel-shaped bay area surface being formed in the cylinder head and extending to said assigned edge region in such a manner that its depth increases.

Claim 36

Dependent Claim 85 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the piston at its top-dead-center position defines along with the cylinder head a squeezing zone of the working chamber, said squeezing zone being defined to begin at the circumference of the piston top and extend inwardly towards the longitudinal axis of the cylinder and be connected to a guide zone leading to said flow aperture and wherein the open height of said guide zone increases from said squeezing zone toward said flow aperture.

Claim 37

Dependent Claim 50 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the radial distance from the center of said flow aperture to the longitudinal axis of the cylinder is greater than the radial distance from the center of the swirl combustion chamber to the longitudinal axis of the cylinder.

Claim 38

Dependent Claim 83 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture includes an edge section part of which is assigned to said primary partial region and another part of which is assigned to said secondary partial region, said part being assigned to said primary partial region being that region where said split-off portion is generated, both parts of said edge region having radii of curvature which are as small as is permitted by the thermodynamic loading in the cylinder.

Claim 39

Dependent Claim 105 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein said flow aperture includes an edge section part of which is assigned to said primary partial region and another part of which is assigned to said secondary partial region, said edge section assigned to said primary partial region having a first sector where said split-off portion is generated and an opposite sector, and said edge section assigned to said secondary partial region having a first sector and an opposite sector, and wherein said first sectors are located generally at a lesser distance from the longitudinal axis of the cylinder than said opposite sectors.

Claim 40

Dependent Claim 20 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the internal combustion engine is a spark-ignition engine.

Claim 41

Dependent Claim 20 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the internal combustion engine is a self-igniting engine.

Claim 42

Dependent Claim 20 words

A two-stroke cycle internal combustion engine as defined in claim 6, wherein the internal combustion engine is a diesel engine.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-04-07	1978-10-07	1979-04-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-04-07	1982-10-07	1983-04-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-04-07	1986-10-07	1987-04-08	$7700.00	Window Closed / Lapsed

Process and apparatus for scavenging the swirl combustion chamber of two-stroke cycle internal combustion engines

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