Two stroke fuel inject engine with scavenged pre-combustion chamber

Claim 2

An engine comprising a main cylinder having a head end, a main piston reciprocable in said main cylinder relative to a position adjacent to said head end, an auxiliary cylinder extending from and communicating with said head end of said main cylinder, an auxiliary piston free of connection with said main piston and including a face in opposing relation to said main piston and a rear side remote from said main cylinder head end, said auxiliary piston being movable in said auXiliary cylinder between an extended position with said face adjacent to said head end of said main cylinder and a retracted position with said face spaced from said head end of said main cylinder, said auxiliary piston defining, when in said retracted position, an initial combustion chamber in said auxiliary cylinder extending between said main cylinder head end and said auxiliary piston and said auxiliary piston effecting full scavenging of said initial combustion chamber in response to travel from said retracted position to said extended position, said auxiliary cylinder including a portion extending from said rear side of said auxiliary piston and being closed to prevent fluid flow therethrough relative to said auxiliary cylinder portion, and a valveless means permitting restricted fluid flow between said auxiliary cylinder portion and the space adjacent to said auxiliary piston face.

Claim 3

An engine in accordance with claim 1 wherein said engine is a two stroke engine and further including an air inlet port and an exhaust port in said cylinder remote from said head end, said air inlet and exhaust ports being opened and closed in response to main piston movement.

Claim 4

An engine in accordance with claim 1 wherein said auxiliary cylinder extends co-axially from said main cylinder and each of said main piston and said auxiliary piston includes a piston face with a centered protuberance extending toward the other piston face to cause turbulence in the gases in said initial combustion chamber upon movement of said main piston to adjacent to said head end of said main cylinder.

Claim 5

An engine comprising a main cylinder having a head end, a main piston reciprocable in said main cylinder relative to a position adjacent to said head end, a closed auxiliary cylinder extending from said head end of said main cylinder, and including a first bore adjacent to said main cylinder and a concentric axially adjacent second bore remote from said main cylinder and having a diameter larger than the diameter of said first bore, an auxiliary piston, having a face, a skirt extending from the circular periphery of said face and having a diameter closely approximating the diameter of said first bore, and a radially outwardly extending flange projecting from said skirt remote from said face and having an outer cylindrical surface with a diameter approximating the diameter of said second bore, said auxiliary piston being movable in said auxiliary cylinder between an extended position adjacent to said main cylinder when said main piston is remote from said head end of said main cylinder and a retracted position remote from said head end of said main cylinder when said main piston is adjacent to said head end of said main cylinder, whereby to define, when said auxiliary piston is in said retracted position, an initial combustion chamber between said auxiliary piston and said main piston, a by-pass slot extending radially outwardly from and axially of said second bore and terminating, at one end, in axially spaced relation from the end of said second bore adjacent to said first bore and, at the other end, beyond said flange in the direction away from said head end of said main cylinder when said auxiliary piston is in said retracted position, and fuel injection means communicating with said initial combustion chamber.

Claim 6

An engine comprising a main cylinder having a head end, a main piston reciprocable in said main cylinder relative to a position adjacent to said head end, a closed auxiliary cylinder extending from said head end of said main cylinder, and including a first bore adjacent to said main cylinder and a concentric axially adjacent second bore remote from said main cylinder and having a diameter larger than the diameter of said first bore, an auxiliary piston, having a face, a skirt extending from the circular periphery of said face and having a diameter closely approximating the diameter of said first bore, and a radially outwardly extending flange projecting from said skirt remote from said face and having an outer cylindrical surface with a diameter approximating the diameter of said second bore, said auxiliary piston being movable in said auxiliary cylinder between an extended position adjacent to said main cylinder when said main piston is remote from said head end of said main cylinder and a retracted position remote from said head end of said main cylinder when said main piston is adjacent to said head end of said main cylinder, whereby to define, when said auxiliary piston is in said retracted position, an initial combustion chamber between said auxiliary piston and said main piston, a by-pass slot extending radially outwardly from and axially of said second bore and terminating, at one end, in axially spaced relation from the end of said second bore adjacent to said first bore and, at the other end, beyond said flange in the direction away from said head end of said main cylinder when said auxiliary piston is in said retracted position, and fuel injection means communicating with said initial combustion chamber.

Claim 7

An engine in accordance with claim 1 including a water jacket in close proximity to said auxiliary cylinder.

Claim 8

An engine in accordance with claim 5 including a head cap including a portion projecting into said auxiliary cylinder from the end thereof remote from said main cylinder.

Claim 9

An engine in accordance with claim 6 wherein said projecting part includes water jacket means communicating with said first mentioned water jacket.

Claim 10

An engine comprising a main cylinder having a head end, a main piston reciprocable in said main cylinder relative to a position adjacent to said head end, a closed auxiliary cylinder extending from said head end of said main cylinder, and an auxiliarY piston movable in said auxiliary cylinder between an extended position adjacent to said main cylinder and a retracted position remote from said head end of said main cylinder, whereby to define, when said auxiliary piston is in said retracted position, an initial combustion chamber between said auxiliary piston and said main piston, fuel injection means communicating with said initial combustion chamber, and means for affording gas flow from one side to the other of said auxiliary piston including a bleed hole in said piston face from one side to the other thereof.

Claim 11

An engine comprising a main cylinder having a head end, a main piston reciprocable in said main cylinder relative to a position adjacent to said head end, a closed auxiliary cylinder extending from said head end of said main cylinder, and an auxiliarY piston movable in said auxiliary cylinder between an extended position adjacent to said main cylinder and a retracted position remote from said head end of said main cylinder, whereby to define, when said auxiliary piston is in said retracted position, an initial combustion chamber between said auxiliary piston and said main piston, fuel injection means communicating with said initial combustion chamber, and means for affording gas flow from one side to the other of said auxiliary piston including a bleed hole in said piston face from one side to the other thereof.

Claim 12

A two stroke fuel injection engine comprising an engine block including means defining a main cylinder having a head end, an exhaust gas port remote from said head end, and an air inlet port remote from said head end, a main piston reciprocable in said main cylinder relative to said ports to effect opening and closure thereof and relative to a position adjacent to said head end, a cylinder head fixed to said engine block and including means defining an auxiliary cylinder extending from said head end of said main cylinder, said auxiliary cylinder including a first bore adjacent to said main cylinder and a concentric axially adjacent second bore remote from said main cylinder and having a diameter larger than the diameter of said first bore, said cylinder head also including coolant jacket passages in close proximity to said auxiliary cylinder, an auxiliary piston movable in said auxiliary cylinder between an extended position adjacent to said main cylinder when said main piston is remote from said head end of said main cylinder and a retracted position remote from said head end of said main cylinder when said main piston is adjacent to said head end of said main cylinder, whereby to define in said auxiliary cylinder and when said auxiliary piston is in said retracted position, an initial combustion chamber in said auxiliary cylinder between said auxiliary piston and said main piston, said auxiliary piston having a face, a skirt extending from the circular periphery of said face and having a diameter closely approximating the diameter of said first auxiliary cylinder bore, and a radially outwardly extending flange projecting from said skirt remote from said face and having an outer cylindrical surface with a diameter approximating the diameter of said second auxiliary cylinder bore, fuel injection means in said cylinder head communicating with said initial combustion chamber, a by-pass slot in said cylinder head extending radially outwardly from and axially of said second auxiliary cylinder bore and terminating, at one end, in axially spaced relation from the end of said second auxiliary cylinder bore adjacent to said first auxiliary cylinder bore and, at the other end, beyond said flange in the direction away from said head end of said main cylinder when said auxiliary piston is in said retracted position, and a head cap connected to said cylinder head for closing the end of said auxiliary cylinder remote from said main cylinder and including a member projecting into said auxiliary cylinder from the end thereof remote from said main cylinder and within said auxiliary piston skirt when said auxiliary piston is in said retracted position, said projecting part including coolant water jacket means communicating with said coolant jacket passages in said cylinder head.

Claim 13

A two stroke fuel injection engine comprising an engine block including means defining a main cylinder having a head end, an exhaust gas port remote from said head end, and an air inlet port remote from said head end, a main piston reciprocable in said main cylinder relative to said ports to effect opening and closure thereof and relative to a position adjacent to said head end, a cylinder head fixed to said engine block and including means defining an auxiliary cylinder extending from said head end of said main cylinder, said auxiliary cylinder including a first bore adjacent to said main cylinder and a concentric axially adjacent second bore remote from said main cylinder and having a diameter larger than the diameter of said first bore, said cylinder head also including coolant jacket passages in close proximity to said auxiliary cylinder, an auxiliary piston movable in said auxiliary cylinder between an extended position adjacent to said main cylinder when said main piston is remote from said head end of said main cylinder and a retracted position remote from said head end of said main cylinder when said main piston is adjacent to said head end of said main cylinder, whereby to define in said auxiliary cylinder and when said auxiliary piston is in said retracted position, an initial combustion chamber in said auxiliary cylinder between said auxiliary piston and said main piston, said auxiliary piston having a face, a skirt extending from the circular periphery of said face and having a diameter closely approximating the diameter of said first auxiliary cylinder bore, and a radially outwardly extending flange projecting from said skirt remote from said face and having an outer cylindrical surface with a diameter approximating the diameter of said second auxiliary cylinder bore, fuel injection means in said cylinder head communicating with said initial combustion chamber, a by-pass slot in said cylinder head extending radially outwardly from and axially of said second auxiliary cylinder bore and terminating, at one end, in axially spaced relation from the end of said second auxiliary cylinder bore adjacent to said first auxiliary cylinder bore and, at the other end, beyond said flange in the direction away from said head end of said main cylinder when said auxiliary piston is in said retracted position, and a head cap connected to said cylinder head for closing the end of said auxiliary cylinder remote from said main cylinder and including a member projecting into said auxiliary cylinder from the end thereof remote from said main cylinder and within said auxiliary piston skirt when said auxiliary piston is in said retracted position, said projecting part including coolant water jacket means communicating with said coolant jacket passages in said cylinder head.

Claim 14

An engine in accordance with claim 9 wherein said auxiliary cylinder extends co-axially from said main cylinder, wherein said main piston also includes a transverse face and wherein said piston faces each include a centered protuberance extending toward the other piston face to cause turbulence in the gases in said initial combustion chamber upon movement of said main piston to adjacent to said head end of said main cylinder.

Claim 15

An engine in accordance with claim 1 wherein said valveless means comprises a bleed hole in said auxiliary piston.

Claim 16

An engine in accordance with claim 1 wherein said auxiliary cylinder extends substantially co-axially wiTh said main cylinder and has a diameter less then one-half of the diameter of said main cylinder.