Stratified Scavenging Two-Stroke Internal Combustion Engine, Air Cleaner Of The Same, And Intake Method
AssigneeYamabiko Corporation
InventorsHisato OSAWA, Takahiro YAMAZAKI, Hidekazu TSUNODA, Yuuta KOBAYASHI
Life of this patent
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Abstract
An amplitude of a pressure fluctuation in a vicinity of a main nozzle of a carburetor (32) is decreased. An air cleaner (30) has a first inlet (60) that feeds air to an intake system air channel, and a second inlet (62) that feeds air to an intake system air-fuel mixture channel. A channel formation member (70) is attached to the second inlet (62). A channel length (L2) of an extension channel (72) formed by the channel formation member (70) is 110 mm or more.
Claims16
A stratified scavenging two-stroke internal combustion engine configured to feed a combustion chamber with first leading air and subsequently with air-fuel mixture from a crank chamber in a scavenging stroke of the engine, comprising:
- an intake device having an air channel and an air-fuel mixture channel, the air channel feeding the leading air to an engine body, and the air-fuel mixture channel generating the air-fuel mixture and feeding the air-fuel mixture to the crank chamber of the engine body;
- and
- an opening portion provided in the intake device to make communication between the air channel and the air-fuel mixture channel,
- wherein one of the air channel and the air-fuel mixture channel is longer by 110 mm or more than the other of the air channel and the air-fuel mixture channel when viewed in an upstream side of the opening portion.
An air cleaner for a stratified scavenging two-stroke internal combustion engine, the engine having
- an engine body configured to feed a combustion chamber with first leading air and subsequently with air-fuel mixture from a crank chamber in a scavenging stroke of the engine,
- an air channel for feeding air for the leading air to the engine body,
- an air-fuel mixture channel for feeding the air-fuel mixture to a crank chamber of the engine body,
- a carburetor including a main nozzle for feeding fuel to the air-fuel mixture channel, and
- an opening portion making communication between the air channel and the air-fuel mixture channel,
- the air cleaner comprising:
- a cleaner element for filtering outside air;
- a first inlet for feeding purified air filtered through the cleaner element to the air channel;
- a second inlet for feeding the purified air filtered through the cleaner element to the air-fuel mixture channel;
- and
- a channel formation member attached to one of the first inlet and the second inlet to extend said one of the first inlet and the second inlet,
- wherein a channel length of an extension channel formed by the channel formation member is 110 mm or more.
An intake method of a stratified scavenging two-stroke internal combustion engine configured to feed a combustion chamber with first leading air and subsequently with air-fuel mixture from a crank chamber in a scavenging stroke of the engine,
- wherein the engine has
- an air channel for feeding purified air filtered through an cleaner element to an engine body,
- an air-fuel mixture channel for feeding the purified air to a carburetor to generate air-fuel mixture with fuel from a main nozzle in the carburetor, and feeds the air-fuel mixture to the crank chamber, and
- an opening portion making communication between the air channel and the air-fuel mixture channel, the opening portion being located in a vicinity of the main nozzle,
- wherein one of the air channel and the air-fuel mixture channel is longer than the other of the air channel and the air-fuel mixture channel when viewed in an upstream side of the opening portion, and
- wherein the intake method comprises
- a first step for generating air flow in in the air channel,
- a second step for generating air-fuel mixture flow in the air channel,
- a third step for making contact of the air flow and the air-fuel mixture flow through the opening portion to make pressure fluctuations of these flows to interfere with each other and thereby decrease a pressure fluctuation in a vicinity of the main nozzle.
Dependencies are inferred from the claim text.