Exhaust gas purification device for an internal combustion engine
    41.
    发明授权
    Exhaust gas purification device for an internal combustion engine 失效
    内燃机用废气净化装置

    公开(公告)号:US5974794A

    公开(公告)日:1999-11-02

    申请号:US54172

    申请日:1998-04-02

    摘要: The exhaust gas purification device includes a NO.sub.x absorbent disposed in an exhaust gas passage of an internal combustion engine. The engine is mainly operated at a lean air-fuel ratio. The NO.sub.x absorbent absorbs NO.sub.x in the exhaust gas from the engine when the exhaust gas flowing into the NO.sub.x absorbent is at a lean air-fuel ratio, and releases the NO.sub.x absorbed therein and reduces it when the air-fuel ratio of the exhaust gas becomes a rich air-fuel ratio. A control circuit is provided for controlling the operating air-fuel ratio of the engine. When the ignition switch of the engine is turned off, the control circuit continues the engine operation for a predetermined period before terminating the engine operation. During this engine operation, the operating air-fuel ratio of the engine is controlled at a rich air-fuel ratio to supply exhaust gas with a rich air-fuel ratio to the NO.sub.x absorbent. Therefore, NO.sub.x absorbed and held therein when the ignition switch is turned off is released and reduced by the rich air-fuel ratio exhaust gas from the engine. Since the NO.sub.x absorbent is maintained at the condition where no NO.sub.x remains in the NO.sub.x absorbent after the engine has stopped, unreduced NO.sub.x is not released from the NO.sub.x absorbent even if the NO.sub.x absorbent is cooled after the engine has stopped.

    摘要翻译: 废气净化装置包括设置在内燃机的废气通道中的NOx吸收剂。 发动机主要运行在稀薄的空燃比。 当排入NOx吸收剂的排气处于稀薄的空燃比时,NOx吸收剂吸收来自发动机的废气中的NOx,并且当排气的空燃比变为 丰富的空燃比。 提供控制电路用于控制发动机的运转空燃比。 当发动机的点火开关关闭时,控制电路在终止发动机运转之前,继续发动机运转一段预定的时间。 在该发动机运转中,将发动机的运转空燃比控制在较大的空燃比,以向NOx吸收剂供给浓空燃比的排气。 因此,当点火开关关闭时吸收并保持的NOx被释放并由来自发动机的富空燃比废气减少。 由于NOx吸收剂在发动机停止之后保持在NOx吸收剂中不存在NOx的状态,所以即使在发动机停止后NOx吸收剂被冷却,未还原的NOx也不会从NOx吸收剂中释放。

    Apparatus and method for purifying exhaust gas in an internal combustion
engine
    42.
    发明授权
    Apparatus and method for purifying exhaust gas in an internal combustion engine 失效
    一种用于净化内燃机废气的装置和方法

    公开(公告)号:US5848529A

    公开(公告)日:1998-12-15

    申请号:US933618

    申请日:1997-09-08

    摘要: An apparatus for, and a method of, purifying exhaust gas emitted from an internal combustion engine reduces fuel consumption under a lean operating condition and generates high torque under a rich operating condition without deteriorating the cleanness of exhaust gas and the driveability of the engine. The apparatus and method improve the durability of a variable valve timing mechanism of the engine. The engine operation involves lean and rich operating conditions. The variable valve timing mechanism of the apparatus changes the open and close timing of at least one of intake and exhaust valves of the engine. The apparatus further has a catalytic converter in an exhaust system, to occlude NOx under the lean operating condition and discharge and reduce the occluded NOx under the rich operating condition. The apparatus also has a prohibition unit for prohibiting the variable valve timing mechanism from changing the valve open and close timing of the valves when the air-fuel ratio of the engine is changed from lean to rich to discharge and reduce the occluded NOx.

    摘要翻译: 用于净化从内燃机排出的废气的装置和方法,在稀薄运行状态下降低燃料消耗,并且在丰富的运行状态下产生高扭矩,而不会降低排气的清洁度和发动机的驱动性。 该装置和方法提高了发动机的可变气门正时机构的耐久性。 引擎操作涉及精益和丰富的操作条件。 该装置的可变气门正时机构改变发动机的进气门和排气门中的至少一个的打开和关闭正时。 该装置还具有排气系统中的催化转化器,以在稀薄运行状态下封闭NOx,并在富运行条件下排放并减少封闭的NOx。 该装置还具有禁止单元,用于当发动机的空燃比从稀燃变为浓度以排出并且减少封闭的NOx时,禁止可变气门正时机构改变阀的开阀和关闭正时。