Catalyst unit and exhaust structure of engine including same
AssigneesKawasaki Jukogyo Kabushiki Kaisha, Nichidai Filter Corporation, Shinba Iron Works Corporation
InventorsKazuki Masui, Takaharu Minami, Tadashi Kato, Hideki Takatsuka, Noboru Ishizawa
Life of this patent
Estimating the term…
Abstract
A muffler is detachably attached to an engine. A catalyst for purifying exhaust gas is provided upstream of the muffler, and a secondary air valve for supplying air to an exhaust passage is provided upstream of the catalyst. The catalyst and the secondary air valve are integrally unitized. A catalyst unit including the catalyst and the secondary air valve is provided between the engine and the muffler.
Claims17
A catalyst unit comprising:
- a pipe member forming an exhaust passage from an engine and including a connection portion to which a muffler is connected;
- a catalyst which is provided in the pipe member and purifies exhaust gas;
- an air mixing chamber which is formed upstream of the catalyst in the pipe member and in which the exhaust gas and outside air are mixed;
- an air supply portion which is stored in the pipe member and supplies the outside air to the air mixing chamber;
- a part, where the air supply portion is stored in the pipe member, that protrudes from the exhaust passage laterally outward;
- and
- a cover for fitting to a cylinder and a cylinder head of the engine and which supplies a cooling wind to the air supply portion, the cover being configured such that the cooling wind is guided to the catalyst.
An exhaust structure of an engine to which a muffler is detachably attached, comprising:
- a catalyst which is disposed upstream of the muffler and purifies exhaust gas;
- a secondary air valve which is disposed upstream of the catalyst and supplies air to an exhaust passage;
- an air mixing chamber disposed upstream of the catalyst in the exhaust passage, the exhaust gas and the air supplied from the secondary air valve being mixed in the air mixing chamber;
- and
- a cover which supplies a cooling wind to the secondary air valve, the cover being configured such that a cooling wind is guided to the catalyst, wherein
- the catalyst and the secondary air valve are integrally unitized to form a catalyst unit,
- apart of the secondary air valve protrudes from the exhaust passage laterally outward, and
- the cover is fitted to a cylinder and a cylinder head of the engine.
An exhaust structure of an engine to which a muffler is detachably attached, comprising:
- a catalyst which is disposed upstream of the muffler and purifies exhaust gas;
- a secondary air valve which is disposed upstream of the catalyst and supplies air to an exhaust passage;
- an air mixing chamber formed upstream of the catalyst in the exhaust passage, the exhaust gas and the air supplied from the secondary air valve being mixed in the air mixing chamber;
- a secondary air introducing passage communicating with the air mixing chamber in the exhaust passage and being separate from the air mixing chamber, via the secondary air introducing passage the air from the secondary air valve being supplied to the air mixing chamber;
- and
- a cover which supplies a cooling wind to the secondary air valve, the cover being configured such that the cooling wind is guided to the catalyst, wherein
- the catalyst and the secondary air valve are integrated with a cylinder head, to form a catalyst unit,
- a part of the secondary air valve protrudes from the exhaust passage laterally outward, and
- the cover is fitted to a cylinder and a cylinder head of the engine.
Dependencies are inferred from the claim text.