Abstract: A regeneration device for a filter (13) which traps particulate matter in an exhaust gas of an engine (1) is disclosed. The regeneration device has a sensor (25) which detects an engine running point containing an engine load and a controller (22) storing a map which defines a low load region (A) relating to engine running points. The controller (22) determines whether or not the detected engine running point is in the low load region referring to the map, when the deposition amount of particulate matter is more than a first reference amount (PMn). Further, the controller (22) immediately start a first filter regeneration control by raising a temperature of the exhaust gas, when the detected engine running point is not in the low load region, and start a second filter regeneration control by raising the temperature of the exhaust gas after the deposition amount of particulate matter exceeds a second reference amount (PMe), when the detected engine running point is in the low load region.

Abstract: A filter (41) traps particulate matter in the exhaust gas of a vehicle diesel engine (1). A vehicle speed sensor (51) detects a vehicle speed, and a controller (31) determines a vehicle running pattern from the vehicle speed. In the regeneration of the filter (41) to eliminate trapped particulate matter by burning, the controller (31) controls the exhaust gas temperature of the diesel engine (1) to a different target temperature according to the running pattern. As a result, there are less opportunities for regeneration of the filter (41) to be interrupted due to exhaust gas temperature drop, and regeneration of the filter (41) is ensured.

Abstract: An exhaust gas purifying system for an automotive internal combustion engine. The exhaust gas purifying system comprises a particulate filter disposed in an exhaust gas passageway of the engine to collect particulate in exhaust gas flowing through the exhaust gas passageway. The collected particulate is burnt off to be removed by raising a temperature of exhaust gas in a condition in connection with the particulate filter. A plurality of devices are provided for raising the temperature of exhaust gas to be introduced into the particulate filter through the exhaust gas passageway when the collected particulate is burned off to be removed. Additionally, a control unit is configured to select at least one of the devices in accordance with an engine operating region and preferentially operate the selected at least one of the devices for raising the exhaust gas temperature.

Abstract: In regeneration apparatus and method for a particulate filter that collects a particulate in exhaust gas of an internal combustion engine, a timing at which an accumulated particulate is combusted to regenerate the particulate filter is determined and a control is performed for a combustion of the particulate, during the control for the combustion of the particulate, a temperature of the engine exhaust gas is raised to a first target temperature set at a temperature equal to or higher than a criterion temperature which provides a criterion of whether the particulate is combusted to regenerate the particulate filter when the engine falls in a first driving region, and the engine exhaust gas temperature is raised to a second target temperature set at a temperature lower than the criterion temperature when the engine falls in a second driving region different from the first driving region.

Abstract: An exhaust gas purifying system of a diesel engine comprises a PM filter installed in an exhaust passage line of the engine to collect particulate matter (PM) in the exhaust gas from s the engine; a pressure difference sensor for detecting a pressure difference between upstream and downstream portions of the PM filter; a control unit which comprises a collected PM amount estimating section that estimates an amount of collected PM in the PM filter based on the pressure difference; and a reactivation timing judging section that, based on the estimated amount of the collected PM, judges a reactivation time when the reactivation of the PM filter is needed; and a reactivation carrying out system that, upon judgment of the reactivation time, carries out a predetermined operation to increases the temperature of the PM filter thereby to burn the collected PM.

Abstract: An exhaust gas purification system includes a particulate filter, a sensor that detects a filter differential pressure and a controller that controls regeneration of the particulate filter. The controller is programmed to execute a control for burning particulate accumulated on the particulate filter, determine whether regeneration of the particulate filter is completed, detect, in cooperation with the sensor, a filter differential pressure immediately after it is determined that regeneration of the particulate filter is completed, and estimate an ash accumulation amount based on the detected filter differential pressure. An exhaust gas purification method is also provided.

Abstract: An exhaust passage (2) of a diesel engine (1) is provided with a filter (41) for trapping particulate matter. Regeneration of the filter (41) is divided into first to third phases. In the first phase the filter temperature is raised to the combustion temperature of the particulate matter in a short period of time through control of the exhaust gas temperature. In the second phase, the oxygen concentration of the exhaust gas is held at a predetermined low level while the filter temperature is maintained so as to prevent excessive combustion of particulate matter. In the third phase, wherein the amount of trapped particulate matter has been reduced, the oxygen concentration of the exhaust gas is held at a predetermined high level while the filter temperature is maintained so as to complete the combustion of the trapped particulate matter.

Abstract: A color image forming apparatus includes a carrier belt which runs along a transport path of a recording medium to transport the recording medium. A number of image-forming sections are aligned in the transport path. Each of the plurality of image-forming sections forms a toner image of a corresponding color included in an image signal. A plurality of transfer units are provided, with each being disposed to oppose a corresponding one of the number of image-forming sections. Each of the number of transfer units transferring the toner image of the corresponding color to the recording medium. A fixing unit is provided that fixes the toner image to the recording medium. A controller is provided that detects a number of colors in the image signal. The controller sets one set of speeds from a plurality of different sets of speeds in accordance with the number of colors.

Abstract: A color image forming apparatus provides the prolonged life of the photosensitive drums, carrier belt, and toner of the respective colors and improves the quality of the printed color image. A carrier belt transports a recording medium placed thereon so that the recording medium passes through a plurality of printing mechanisms which print images of different colors on the recording medium in superposition. Each printing mechanism prints an image of a corresponding color. The printing mechanism is adapted to be moved into its operative position where the photosensitive drum of the printing mechanism is in contact with the carrier belt to print the image on the recording medium, and into its non-operative position where the photosensitive drum of the printing mechanism is not in contact with the carrier belt.