An exhaust gas purification device for an internal combustion engine
    11.
    发明公开
    An exhaust gas purification device for an internal combustion engine 有权
    一种内燃机的排气净化装置

    公开(公告)号:EP0974746A2

    公开(公告)日:2000-01-26

    申请号:EP99114075.7

    申请日:1999-07-20

    IPC分类号: F02D41/14 F01N3/20

    摘要: An NOx occluding and reducing catalyst is disposed in an exhaust gas passage of an internal combustion engine that operates at a lean air-fuel ratio. When the engine is operating at a lean air-fuel ratio, the NOx occluding and reducing catalyst absorbs NOx in the exhaust gas. To release NOx, the engine is operated at a rich air-fuel ratio so that the exhaust gas flowing into the NOx occluding and reducing catalyst acquires a rich air-fuel ratio. While the engine is operated in a region of moderate lean air-fuel ratios of from the stoichiometric air-fuel ratio to an air-fuel ratio of about 20 at the time when the engine operating air-fuel ratio is changing from a lean air-fuel ratio operation to a rich air-fuel ratio operation, an electronic control unit (ECU) of the engine injects secondary fuel, that does not contribute to combustion, into the cylinders of the engine through the direct cylinder fuel injection valves in the expansion stroke or the exhaust stroke of the cylinders, so that the exhaust gas flowing into the NOx occluding and reducing catalyst acquires a rich air-fuel ratio. This prevents unpurified NOx from flowing out of the NOx occluding and reducing catalyst at the time when the engine operating air-fuel ratio is changed.

    摘要翻译: NOx吸留还原催化剂设置在以稀空燃比运转的内燃机的排气通路中。 当发动机以稀空燃比运转时,NOx吸留还原催化剂吸收排气中的NOx。 为了释放NOx,发动机以浓空燃比运行,使得流入NOx吸留还原催化剂的排气获得浓空燃比。 当发动机在发动机运转空燃比从稀空燃比变化时开始在从理论空燃比到约20的空燃比的中等稀空燃比区域内运转时, 发动机的电子控制单元(ECU)在膨胀冲程中通过直列气缸燃料喷射阀向发动机的气缸内喷射不参与燃烧的辅助燃料 或气缸的排气冲程,使得流入NOx吸留还原催化剂的排气获得浓空燃比。 这防止了未净化的NOx在发动机工作空燃比变化时从NOx吸留还原催化剂流出。

    An exhaust gas purification device for an internal combustion engine

    公开(公告)号:EP0869267A2

    公开(公告)日:1998-10-07

    申请号:EP98106083.3

    申请日:1998-04-02

    IPC分类号: F02D41/14 F01N3/08

    摘要: The exhaust gas purification device includes a NO 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 x absorbent absorbs NO x in the exhaust gas from the engine when the exhaust gas flowing into the NO x absorbent is at a lean air-fuel ratio, and releases the NO 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 x absorbent. Therefore, NO 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 x absorbent is maintained at the condition where no NO x remains in the NO x absorbent after the engine has stopped, unreduced NO x is not released from the NO x absorbent even if the NO x absorbent is cooled after the engine has stopped.

    Exhaust gas purification system for an internal combustion engine
    16.
    发明公开
    Exhaust gas purification system for an internal combustion engine 失效
    内燃机废气净化系统

    公开(公告)号:EP0433772A2

    公开(公告)日:1991-06-26

    申请号:EP90123338.7

    申请日:1990-12-05

    IPC分类号: F01N3/20

    摘要: An exhaust gas purification system for an internal combustion engine includes a catalyst (4, 21A, 2B, 2C, 2D, 2E, 2F) installed in an exhaust conduit of an engine (2, 1A, 1B, 1D, 1E, 1F) and constructed of zeolite carrying at least one kind of metal selected from transition metals and noble metals to reduce nitrogen oxides included in the exhaust gas from the engine under an oxidizing gas condition and in the presence of hydrocarbons. The system further includes means for repeating a cycle of cooling the catalyst (4, 21A, 2B, 2C, 2D, 2E, 2F) and then stopping the cooling to allow the catalyst to rise in temperature so that the temperature rising courses of the catalyst are positively and repeatedly produced. Since the catalyst can show a higher nitrogen oxides reducing ability in the temperature rising course than in the temperature lowering course, the NOx purification rate is greatly improved due to the positive production of the temperature rising courses.

    摘要翻译: 一种用于内燃机的排气净化系统包括安装在发动机(2,1A,1B,1D,1E,1F)的排气管道中的催化剂(4,21A,2B,2C,2D,2E,2F)和 由携带选自过渡金属和贵金属中的至少一种金属的沸石构成,以在氧化气体条件下和在烃存在下还原发动机排气中包含的氮氧化物。 该系统还包括用于重复冷却催化剂(4,21A,2B,2C,2D,2E,2F)并然后停止冷却以使催化剂升温的循环的装置,使得催化剂的升温过程 积极和反复产生。 由于催化剂在升温过程中的氮氧化物还原能力高于降温过程中的氮氧化物还原能力,所以由于升温过程的积极产生,NOx净化率大大提高。

    Exhaust gas purification system for an internal combustion engine using alcohol blended gasoline for fuel
    17.
    发明公开
    Exhaust gas purification system for an internal combustion engine using alcohol blended gasoline for fuel 失效
    使用汽油 - 醇混合物作为燃料的内燃机排放控制系统。

    公开(公告)号:EP0430269A2

    公开(公告)日:1991-06-05

    申请号:EP90122902.1

    申请日:1990-11-29

    发明人: Katoh, Kenji

    IPC分类号: F01N9/00 F01N3/20

    摘要: An exhaust gas purification system for an internal combustion engine using an alcohol blended gasoline fuel includes a lean NOx catalyst (2) capable of reducing nitrogen oxides under an oxidizing gas condition and in the presence of hydrocarbons. A bypass conduit (3) is provided with a bypass valve (4) so as to bypass the lean NOx catalyst (2). Opening of the bypass valve (4) to cause the exhaust gas to flow through the bypass conduit (3) is controlled in accordance with the alcohol concentration of the fuel. When the alcohol concentration (C AL ) is low, the bypass valve opening range is limited to a high engine speed and high engine load range, so that the exhaust gas is caused to flow through the lean NOx catalyst (2) at low and medium engine speeds and low and medium engine loads, and the catalyst (2) is utilized at a maximum. On the other hand, when the alcohol concentration (C AL ) is high, the bypass valve opening range is determined so as to include a medium to high engine speed and medium to high engine load range, so that the exhaust gas is caused to flow through the bypass conduit (3) at medium engine speeds and medium engine loads, and useless degradation of the lean NOx catalyst (2) is prevented.

    摘要翻译: 用于内燃发动机的排气净化系统,使用酒精汽油混合燃料包括稀燃NOx催化剂(2),其能够在氧化性气体的条件下和在烃类的存在下将氮氧化物还原的。 旁通管道(3)上设置有旁通阀(4),以便绕过稀燃NOx催化剂(2)。 旁通阀的开口(4),以使废气通过旁通管道(3)在雅舞的燃料的酒精浓度来控制流动。 当醇的浓度(CAL)是低时,旁通阀开度范围限制在高发动机速度和高负载范围内,所以没有排气气流经稀燃NOx催化剂(2)在低和中等的发动机流 速度和低和中等发动机负荷,及催化剂(2)在最大利用。 在另一方面,当醇的浓度(CAL)是高时,旁通阀开度范围是确定性的开采,以便包括到高的发动机转速和中等至高发动机负载范围内的介质中,所以没有排气气流经流 在中等发动机速度和中等发动机负荷和稀燃NOx催化剂(2)的无用降解的旁路导管(3)被防止。