Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L11/00—Valve arrangements in working piston or piston-rod
  • F01L11/02—Valve arrangements in working piston or piston-rod in piston
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/36—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle
  • F01L1/38—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle for engines with other than four-stroke cycle, e.g. with two-stroke cycle

Definitions

• This invention relates to a valve control for a combustion engine. More particularly, it concerns the control of an inlet valve arranged in the piston of a two-stroke engine.
• the piston valve can open and close to flow from the underside of the piston in that it is influenced by the differential pressure across the piston.
• US patent 5603291 discloses a combustion engine, in which the piston is provided with an exhaust valve.
• the exhaust valve is controlled via a push rod by an eccentric surface of the crankshaft.
• the design is not suitable for a two-stroke engine provided with a flush air chamber in the cylinder below the piston.
• the invention has as its object to remedy the drawbacks of the prior art.
• a piston with a preferably fixedly connected piston rod is movably arranged in a combustion engine cylinder.
• the piston rod extends through a sealing in the lower portion of the cylinder.
• the cylinder volume located below the piston is supplied with flush air, preferably through a check valve in the lower portion of the cylinder.
• the combustion engine cylinder is provided with the necessary devices according to techniques known per se for cooling and for the supply of fuel and also an outlet for waste gases .
• the piston rod is connected to a slide.
• the slide running in a guide, is movable in the direction of movement of the piston rod, and the slide is arranged to absorb forces acting on the slide in other directions .
• the piston, piston rod and slide together are arranged to perform a reciprocating movement along the axial centre axis of the piston.
• an intermediate rod is articulated with the slide by means of an articulated axle.
• the piston valve is movable between an open position and a closed position relative to the piston.
• An axial bore extending through the piston rod forms a communication opening between the piston valve and an actuator at the opposite portion of the piston rod relative to the piston valve.
• the connection between the piston valve and actuator can be mechanical, for example.
• the piston valve is provided with a guide portion extending into the through bore of the piston rod.
• a plunger is arranged in the through bore of the piston rod, at the opposite lower end portion of the piston rod.
• the volume of the through bore is filled with fluid, typically with oil, which can advantageously be supplied from the pressure lubrication system of the engine through the intermediate rod.
• the actuator affecting the piston valve via the through bore of the piston rod is arranged to control the relative position of the piston rod valve relative to the piston at least over part of the length of stroke of the piston.
• Figure 1 shows schematically an engine according to the invention, in which the piston is on its way down in the work- ing stroke of the engine.
• the active part of an actuator is in its active position moved towards the piston rod;
• Figure 2 shows the engine of Figure 1, but here the piston is in its lower position, the plunger of the lower portion of the piston rod being prevented by the actuator from moving to its lower position;
• Figure 3 shows the same as Figure 2 , but here the active part of the actuator is in its lower inactive position
• Figure 4 shows the same as Figure 3, but here the piston is shown as it is on its way up in its compression stroke, while at the same time the piston valve is about to close.
• the reference numeral 1 denotes a combustion engine, in the following referred to as the engine, comprising a cylinder 2 provided with a piston 4.
• the engine 1 is a two-stroke engine, in which, in a known manner, the combustion air is compressed in a flush air volume 6 below the piston 4 before flowing into the combustion space 8 of the cyl- inder 2 through a piston valve 10 which opens/closes a through opening 12 in the piston 4.
• a piston rod 13 is fixedly connected to the piston 4 and extends in a known way through a stuffing box 14 arranged in the lower end portion of the cylinder 2.
• the piston rod 13 is connected at its opposite lower end portion to a slide 16.
• the slide 16, running in a guide 18, is movable in the direction of movement of the piston rod 13 and is arranged to absorb forces acting on the slide 16 in other directions.
• an intermediate rod 20 is articulated with the slide 16 by means of a pin bolt 22, the pin bolt 22 also extending through a corresponding bearing bore 25 in the piston rod 13.
• the piston rod 13 is provided with a centred through bore 24.
• the piston valve 10 is restrictedly movable relative to the piston 4, as the piston valve is provided with a guide portion 26 projecting into the bore 24 and being movable between two corresponding shoulders 28 in the bore 24.
• the inward- facing part 30 of the guide portion 26 forms an essentially sealing piston in the bore 24.
• the piston rod 13 is provided with a plunger 32 movable in the bore 24. The plunger 32 is prevented from being moved out of the bore 24 by means of a shoulder 34 in the bore 24.
• the plunger 32 forms an essentially sealing piston in the bore 24.
• the plunger 32 projects somewhat from the lower end portion of the piston rod 13 and is arranged to come to contact on the anchor/active part 38 of an electromagnet/actuator 36 when the piston rod is close to its lower position and the anchor 38 of the electromagnet 36 is in its active posi- tion.
• the bore 24 of the piston rod 13 is supplied with pressurized fluid from the lubrication oil system of the engine 1 through the intermediate rod 20 and the pin bolt 22.
• An exhaust valve 40 is arranged to open to the outflow of combustion gases.
• piston valve 10 is released and can close flow through the opening 12 in the piston 4 as soon as the piston 4 starts its movement in the compression stroke, see Figure 4.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=29417534

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (2)

• 2003
  • 2003-09-22 NO NO20034203A patent/NO319652B1/no unknown
• 2004
  • 2004-09-21 WO PCT/NO2004/000279 patent/WO2005028820A1/en active Application Filing
  • 2004-09-21 EP EP04775063A patent/EP1668229A1/en not_active Withdrawn

Patent Citations (2)

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