Exhaust gas purification device
AssigneeSubaru Corporation
InventorYasuyoshi Sasaki
Life of this patent
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Abstract
An exhaust gas purification device includes a first catalyst, a second catalyst, a bypass pipe, a hydrocarbon adsorbent, and a switching controller. The first catalyst is provided in an exhaust pipe. The second catalyst is provided downstream of the first catalyst in the exhaust pipe. The bypass pipe branches from a first portion of the exhaust pipe. The first portion is located upstream of the second catalyst. The bypass pipe is recoupled to a second portion of the exhaust pipe. The second portion is located upstream of the second catalyst. The hydrocarbon adsorbent is provided in the bypass pipe. The switching controller is configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst.
Claims10
An exhaust gas purification device comprising:
- a first catalyst provided in an exhaust pipe;
- a second catalyst provided downstream of the first catalyst in the exhaust pipe;
- a bypass pipe branching from a first portion of the exhaust pipe, the first portion being located upstream of the second catalyst, the bypass pipe being recoupled to a second portion of the exhaust pipe, the second portion being located upstream of the second catalyst;
- a hydrocarbon adsorbent provided in the bypass pipe;
- and
- a switching controller configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst when the deterioration degree of the first catalyst is equal to or higher than a deterioration threshold, wherein
- the deterioration degree is derived based on a detected value of an air-fuel ratio sensor and another detected value of a downstream air-fuel ratio sensor, and
- the deterioration threshold is an upper limit value of the deterioration degree of the first catalyst at which the first catalyst can remove hydrocarbons to a target value even during an engine start.
An exhaust gas purification device comprising:
- a first catalyst provided in an exhaust pipe;
- a second catalyst provided downstream of the first catalyst in the exhaust pipe;
- a bypass pipe branching from a first portion of the exhaust pipe, the first portion being located upstream of the second catalyst, the bypass pipe being recoupled to a second portion of the exhaust pipe, the second portion being located upstream of the second catalyst;
- a hydrocarbon adsorbent provided in the bypass pipe;
- and
- circuitry configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst when the deterioration degree of the first catalyst is equal to or higher than a deterioration threshold, wherein
- the deterioration degree is derived based on a detected value of an air-fuel ratio sensor and another detected value of a downstream air-fuel ratio sensor, and
- the deterioration threshold is an upper limit value of the deterioration degree of the first catalyst at which the first catalyst can remove hydrocarbons to a target value even during an engine start.
Dependencies are inferred from the claim text.