JP3919741B2 - Exhaust purification device - Google Patents

Description

  The present invention relates to an exhaust emission control device.

  Particulate matter (particulate matter) discharged from a diesel engine as an internal combustion engine is mainly composed of carbonaceous soot and SOF (Soluble Organic Fraction) composed of high-boiling hydrocarbon components. As a component, the composition further contains a trace amount of sulfate (mist-like sulfuric acid component). As a measure for reducing this type of particulates, a particulate filter is placed in the middle of the exhaust pipe through which the exhaust gas flows. It has been traditionally equipped.

  This type of particulate filter has a porous honeycomb structure made of a ceramic such as cordierite, and the inlets of the flow paths partitioned in a lattice pattern are alternately sealed, and the inlets are not sealed. About the flow path, the exit is sealed, and only the exhaust gas which permeate | transmitted the porous thin wall which divides each flow path is discharged | emitted downstream.

  Then, the particulates in the exhaust gas are collected and deposited on the inner surface of the porous thin wall, so that the particulates are appropriately burned and removed before the exhaust resistance increases due to clogging. It is necessary to regenerate, but in normal diesel engine operating conditions, there are few opportunities to obtain exhaust temperatures that are high enough for the particulates to self-combust. For example, an appropriate amount for platinum-supported alumina A catalyst regeneration type particulate filter in which an oxidation catalyst formed by adding a rare earth element such as cerium is integrally supported is being put to practical use.

  That is, if such a catalyst regeneration type particulate filter is employed, the oxidation reaction of the collected particulates is promoted to lower the ignition temperature, and the particulates can be burned and removed even at an exhaust temperature lower than the conventional one. It becomes possible.

  However, even when such a catalyst regeneration type particulate filter is employed, the oxidation catalyst supported by the particulate filter has an active temperature region, and the exhaust temperature is below the lower limit of activation temperature. In the low operating range, the particulates are not burned and removed well, and the trapped amount exceeds the processing amount of the particulates, so if the operating state at such a low exhaust temperature continues, the oxidation catalyst becomes active. Since the particulate filter may not be regenerated well and the particulate filter may fall into an over-collected state because the particulate filter is not collected. It is considered to regenerate the particulate filter by adding fuel to the exhaust gas.

  In other words, if fuel is added upstream of the particulate filter, the added fuel undergoes an oxidation reaction on the oxidation catalyst of the particulate filter, and the heat of the reaction raises the filter bed temperature, causing the particulate to burn out. Thus, regeneration of the particulate filter is achieved.

  Here, when fuel is added upstream from the particulate filter, it is informed that the particulate filter has fallen into an over-collected state by flashing a notification lamp provided on the instrument panel of the driver's seat, etc. At the same time, it is considered to start regeneration of the particulate filter by pressing a regeneration switch provided on an instrument panel or the like of the driver's seat.

Here, some examples of general exhaust gas purifying devices including such a notification lamp and a regeneration switch have already been disclosed as patent publications (see, for example, Patent Document 1).
JP 2003-155914 A

  However, when the notification lamp is lit to notify that the particulate filter has fallen into the excessive collection state, a command is transmitted from the accumulated amount of particulates through an engine control computer (ECU: Electronic Control Unit). When the information lamp cannot be transmitted from the engine control computer to the notification lamp due to a blowout of the notification lamp or due to some trouble, there is a problem that it is not possible to notify the state of being over-collected. In addition, when regeneration of the particulate filter is started by turning on the regeneration switch, a regeneration command is given from the regeneration switch to the engine control computer, so that the command cannot be transmitted from the regeneration switch to the engine control computer due to some trouble. However, there is a problem that the particulate filter cannot be regenerated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exhaust emission control device capable of checking the operation of the notification means regardless of the excessive collection state of the particulate filter.

According to a first aspect of the present invention, there is provided a catalyst regeneration type particulate filter installed in the middle of an exhaust pipe through which exhaust gas circulates, and forcibly burning and removing the particulates collected by the particulate filter. A forced regeneration means for regenerating the curative filter, an operation means provided in a driver's seat to operate the forced regeneration means, and a notification means capable of receiving and displaying a regeneration request signal from the forced regeneration means,
When the operation means is turned on, it is determined whether or not the engine is stopped, the notification means is turned on in the power supply state under the engine stop, and the operation of the notification means can be checked. This relates to an exhaust emission control device.

  According to a second aspect of the present invention, the operation check of the notification means can be ended when the operation means is turned off or when the notification means is turned off by starting the engine. The present invention relates to an exhaust purification device.

  According to the third aspect of the present invention, when it is determined whether or not the engine is stopped, the particulate filter can be regenerated if the operating means is in an ON state while the engine is driven. The exhaust emission control device according to claim 1.

  Thus, according to the present invention, when the operation means is turned on, the presence or absence of the engine stop is determined, and the notification means is turned on in the power supply state under the engine stop. Regardless of the state of being in an overcollected state, it is possible to suitably check the operation of the notification means. At the same time, since the operation means is turned on, the operation means can be suitably checked regardless of the regeneration of the particulate filter.

  When the operation means is turned off, or when the notification means is turned off by starting the engine, the operation check of the notification means can be completed, regardless of the excessive collection state of the particulate filter, It is possible to easily return the notification means to the original state, and preferably finish the operation check of the notification means.

  When it is determined whether or not the engine is stopped, if the operating means is in the ON state while the engine is running, the particulate filter can be regenerated. Since the operation check of the notification means and the regeneration of the particulate filter are separated, the regeneration of the particulate filter can be prevented during the operation check of the notification means.

  According to the exhaust gas purification apparatus of the present invention described above, when the operation means is turned on, the presence or absence of the engine stop is determined, and the notification means is turned on in the power supply state under the engine stop. Regardless of the state in which the filter is trapped, it is possible to achieve an excellent effect that the operation of the notification means can be suitably checked.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show an example of an embodiment of the present invention, FIG. 1 is a schematic view showing an example of an embodiment of the present invention, and FIG. 2 is a sectional view showing details of the particulate filter of FIG. FIG. 3 is a perspective view showing a detail of the oxidation catalyst of FIG. 1 with a part cut away, and FIG. 4 is a flowchart showing an example of checking the operation of the notification lamp and the operation switch.

  In the exhaust emission control device of this embodiment, reference numeral 1 in FIG. 1 denotes a diesel engine of a vehicle equipped with a turbocharger 2 and equipped with an automatic transmission (not shown), and intake air 4 led from an air cleaner 3. Is introduced into the compressor 2a of the turbocharger 2 through the intake pipe 5 and pressurized, and the pressurized intake air 4 is distributed and introduced to each cylinder of the diesel engine 1 via the intercooler 6.

  Further, the exhaust gas 8 discharged from each cylinder of the diesel engine 1 through the exhaust manifold 7 is sent to the turbine 2b of the turbocharger 2, and the exhaust gas 8 driving the turbine 2b passes through the exhaust pipe 9 to the outside of the vehicle. To be discharged.

  A filter case 10 is interposed in the middle of the exhaust pipe 9, and a catalyst regeneration type particulate filter 11 that integrally carries an oxidation catalyst is provided in the rear stage in the filter case 10. As shown in an enlarged view in FIG. 2, the particulate filter 11 has a porous honeycomb structure made of ceramic, and the inlets of the respective flow paths 11a partitioned in a lattice pattern are alternately arranged. For the flow path 11a that is sealed and whose inlet is not sealed, its outlet is sealed, and only the exhaust gas 8 that has permeated through the porous thin wall 11b that defines each flow path 11a is downstream. It is designed to be discharged to the side.

  Further, a flow-through type oxidation catalyst 12 having a honeycomb structure as shown in an enlarged view in FIG. 3 is accommodated in a position immediately before the particulate filter 11 in the filter case 10.

  A temperature sensor 13 is provided between the oxidation catalyst 12 and the particulate filter 11 in the filter case 10 to measure the temperature of the exhaust gas 8 as a substitute value for the catalyst bed temperature. The detection signal 13a is input to a control device (forced regeneration means) 14 constituting an engine control computer (ECU: Electronic Control Unit). In this control device 14, each cylinder of the diesel engine 1 is provided. A fuel injection signal 15a for instructing the fuel injection timing and the injection amount is output to a fuel injection device (forced regeneration means) 15 for injecting fuel.

  Further, the control device 14 includes a differential pressure sensor (not shown) connected to a pipe taken from the inlet side and the outlet side of the filter case 10, and the pressure difference between the inlet side and the outlet side of the particulate filter 11. Thus, the particulate accumulation amount in the particulate filter 11 may be obtained and detected. Alternatively, the particulate discharge amount may be estimated from various conditions of the diesel engine 1 and integrated to detect the particulate deposition amount. Here, in the control device 14, a threshold value is set in advance so that the amount of accumulated particulate matter in the particulate filter 11 needs to be regenerated.

  Here, the fuel injection device 15 is constituted by a plurality of injectors (not shown) provided for each cylinder, and the solenoid valve of each injector is controlled to open by the fuel injection signal 15a, and the fuel injection timing. In addition, the injection amount (valve opening time) is appropriately controlled. Further, an exhaust brake 16 capable of adjusting the opening degree is provided at an appropriate position upstream of the particulate filter 11 so as to narrow the flow path of the exhaust pipe 9 to an appropriate opening degree. The opening degree is controlled by an opening degree command signal 16 a from the control device 14.

  The accelerator of the driver's seat (not shown) is provided with an accelerator sensor 17 (load sensor) that detects the accelerator opening as a load of the diesel engine 1, and the rotational speed is set at an appropriate position of the diesel engine 1. A rotation sensor 18 for detection is provided, and an accelerator opening signal 17a and a rotation speed signal 18a from the accelerator sensor 17 and the rotation sensor 18 are also input to the control device 14.

  In addition, an alarm signal from the control device 14 is displayed on the instrument panel or the like in the driver's seat when the control device 14 determines that the particulate filter 11 has fallen into an overcollected state via various calculation means or sensors. A notification lamp 19 of a notification means that flashes in response to 19a is provided, and a regeneration switch 20 of an operation means that interlocks with the notification lamp 19 and gives an operation command of the fuel injection device 15 or the like via the control device 14 is provided. Is provided.

  In the control device 14, the fuel injection signal 15a in the normal mode is determined based on the accelerator opening signal 17a and the rotational speed signal 18a, while the regeneration command signal 20a is input when the regeneration switch 20 is turned on. When this is done, the normal mode is switched to the regeneration mode, and post-injection is performed at a non-ignition timing later than the compression top dead center following the main injection of fuel performed near the compression top dead center (crank angle 0 °). A fuel injection signal 15a is output.

  That is, in the illustrated example, the control device 14 and the fuel injection device 15 constitute the forced regeneration means of the particulate filter 11, and as described above, from the compression top dead center following the main injection. When post-injection is performed at a timing that does not ignite late, unburned fuel (mainly HC: hydrocarbon) is added to the exhaust gas 8 by the post-injection, and this unburned fuel is added to the particulate filter 11. The oxidation reaction is carried out on the surface oxidation catalyst, and the catalyst bed temperature rises due to the reaction heat, and the particulates in the particulate filter 11 are burned and removed.

  The operation of the embodiment of the present invention will be described below.

  When the vehicle is shipped from the factory or inspected for maintenance or the like, the operation of the regeneration switch 20 and the notification lamp 19 is checked. The operation check is performed by turning on the regeneration switch 20 and performing a predetermined check. Whether or not the notification lamp 19 is turned on under the above conditions, and whether or not the notification lamp 19 is turned off by an operation of turning off the regeneration switch 20, or whether the notification lamp 19 is turned off by starting the engine. Judgment.

  Here, the case where the operation check of the regeneration switch 20 and the notification lamp 19 is checked will be described in detail. As shown in FIG. 4, in the operation check, the state of the regeneration switch 20 is initially OFF by the control device 14 in step S1. If the regeneration switch 20 is in the OFF state (notification lamp 19 extinguished), the process proceeds to step S2 to check whether the regeneration switch 20 is pressed (whether the regeneration switch 20 is turned on) If the regeneration switch 20 is pressed, a signal indicating that the regeneration switch 20 has been turned from OFF to ON is sent to the control device 14, and the process proceeds to step S3. It is determined whether or not the engine is stopped (whether or not the engine is stopped). When the power is supplied under the engine stop, step S4 is performed. Proceeds, it is lit notifying lamp 19 by a command of the control unit 14 ends the operation check of the lighting of the notification lamp 19.

  On the other hand, if the regeneration switch 20 is in the ON state (notification lamp 19 is lit) in step S1, the process proceeds to step S5 to check whether the regeneration switch 20 is pressed again (whether the regeneration switch 20 is turned off). If the regeneration switch 20 is pressed again, a signal indicating that the regeneration switch 20 has been turned on again is sent to the control device 14, and the process proceeds to step S6. It is determined whether or not the engine 1 is stopped (whether or not the engine is stopped). When the power is supplied under the engine stop, the process proceeds to step S7, and the control device 14 automatically switches the regeneration switch 20 from ON to OFF. Then, the notification lamp 19 is turned off, and the operation check for turning off the notification lamp 19 is completed.

  Here, if the regeneration switch 20 is not pressed while the notification lamp 19 is turned off in step S2, the operation proceeds to step S6 without any signal being sent to the control device 14 because there is no operation, and the rotation is similarly performed. It is determined whether or not the diesel engine 1 is stopped by the sensor 18 or the like (whether or not the engine is stopped). When the power is supplied under the engine stop, the process proceeds to step S7, and the state of the regeneration switch 20 is OFF and notification is made. The lamp 19 remains off and the process ends.

  If the regeneration switch 20 is not pressed in step S5 when the notification lamp 19 is lit, the process proceeds to step S8, and whether or not the diesel engine 1 is stopped by the control device 14 via the rotation sensor 18 or the like (engine In the power supply state under the engine stop, the process further proceeds to step S9 to determine whether or not to start the diesel engine 1. If the diesel engine 1 is not started, it is controlled that no operation is performed. The process proceeds to step S4 while maintaining the state of the apparatus 14, and the state of the regeneration switch 20 is ON and the notification lamp 19 is kept on, and the process ends. When the diesel engine 1 is started in step S9, the process proceeds to step S10, and the controller 14 determines whether or not the current particulate accumulation amount (PM accumulation amount) is within a predetermined threshold range. If the particulate accumulation amount is not within the predetermined threshold range, the process proceeds to step S7, the notification lamp 19 is turned off by an instruction from the control device 14, and the operation check for turning off the notification lamp 19 is completed.

  As described above, when the operation of the regeneration switch 20 and the notification lamp 19 is checked, an operation for turning on the regeneration switch 20 is performed to turn on the notification lamp 19 under the above conditions, and to turn off the regeneration switch 20. The notification lamp 19 is turned off under the above conditions, or the diesel engine 1 is started to recognize that the notification lamp 19 is turned off under the above conditions. It is confirmed that there are no malfunctions such as a breakage, a failure in which the command cannot be transmitted from the engine control computer of the control device 14 to the notification lamp 19, and a failure in which the command cannot be transmitted from the regeneration switch 20 to the engine control computer.

  On the other hand, the notification lamp 19 indicates that the particulate filter 11 is being reproduced or that the particulate filter 11 is being reproduced, and the indication such as that the particulate filter 11 is being reproduced is linked with the operation check process described above. Yes.

  Here, the display operation during the regeneration of the particulate filter 11 or the regeneration request of the particulate filter 11 will be described in detail. Similarly, as shown in FIG. 4, the diesel engine 1 is stopped by the rotation sensor 18 or the like in step S3. When determining whether or not the engine is stopped (whether or not the engine is stopped), when the diesel engine 1 is being driven, the process proceeds to step S11, and the current particulate accumulation amount (PM accumulation amount) is set by the control device 14 to a predetermined value. It is determined whether or not the amount is within the threshold range, and if the particulate accumulation amount is within the predetermined threshold range, the process proceeds to step S12, and whether the vehicle is stopped or traveling by the accelerator sensor 17 or the like. When the vehicle is stopped, the process proceeds to step S4, where a notification lamp is sent in accordance with a command from the control device 14. 9 is lit, the particulate filter 11 is completed to indicate that a playing. On the other hand, if it is determined in step S11 that the particulate accumulation amount is not within the predetermined threshold range, the process proceeds to step S7, where the notification lamp 19 is turned off by a command from the control device 14, and the particulate filter 11 is assumed not to be regenerated. It is displayed that the curate filter 11 is not being regenerated, and the process ends. Further, if the particulate accumulation amount is within the predetermined threshold range in step 11 and the vehicle is traveling in step S12, the process proceeds to step S13, and the notification lamp 19 is blinked by a command from the control device 14, and the particulates are displayed. It is displayed that there is a regeneration request for the particulate filter 11 because it is necessary to regenerate the curative filter 11, and the process ends.

  Similarly, when the diesel engine 1 is being driven in step S6, the process proceeds to step 10, and in step 10, if the particulate accumulation amount is within a predetermined threshold range, the process proceeds to step S13, where control is performed. The notification lamp 19 is blinked according to the command of the device 14, and it is displayed that the particulate filter 11 is requested to be regenerated, and the process is terminated. If it is determined in step S10 that the particulate accumulation amount is not within the predetermined threshold range, the process proceeds to step S7, where the notification lamp 19 is turned off by a command from the control device 14, and the particulate filter 11 is assumed not to be regenerated. It is displayed that the curate filter 11 is not being regenerated, and the process ends.

  Further, when it is determined whether or not the diesel engine 1 is stopped by the rotation sensor 18 or the like in step S8 (whether or not the engine is stopped), when the diesel engine 1 is driven, the control proceeds to step S14. The apparatus 14 determines whether or not the current particulate deposition amount (PM deposition amount) is within a predetermined threshold range. If the particulate deposition amount is within the predetermined threshold range, the process proceeds to step S15. Then, it is determined whether the vehicle is running or stopped by the accelerator sensor 17 or the like, and when the vehicle is stopped, the process proceeds to step S4, the notification lamp 19 is turned on by the command of the control device 14, and the particulates It is displayed that the filter 11 is being reproduced, and the process ends. On the other hand, if it is determined in step S14 that the particulate accumulation amount is not within the predetermined threshold range, the process proceeds to step S7, where the notification lamp 19 is turned off by a command from the control device 14, and the particulate filter 11 is assumed not to be regenerated. It is displayed that the curate filter 11 is not being regenerated, and the process ends. Further, when the vehicle is traveling in step S15, the process proceeds to step S13, where the notification lamp 19 is blinked by the command from the control device 14, and the particulate filter 11 needs to be regenerated. Show that there is, and exit.

  As described above, the notification lamp 19 indicates that the particulate filter 11 is being regenerated when the particulate filter 11 is being regenerated or when the particulate filter 11 is being regenerated, and the particulate filter 11 is not being regenerated. Is turned off, and the regeneration request for the particulate filter 11 is indicated by blinking.

  As described above, according to the present embodiment, when the regeneration switch 20 of the operation unit is turned on, the presence or absence of the engine stop is determined, and the notification lamp 19 of the notification unit is in a power supply state under the engine stop. Is turned on, so that the information is transmitted from the engine control computer of the control device 14 to the notification lamp 19 due to a blowout of the notification lamp 19 or any failure regardless of the particulate filter 11 in an overcollected state. The case where it cannot be confirmed is confirmed, and the operation of the notification lamp 19 can be suitably checked. At the same time, since the operation of turning on the regeneration switch 20 of the operation means is performed, the command cannot be transmitted from the regeneration switch 20 to the engine control computer of the control device 14 due to some trouble regardless of regeneration of the particulate filter 11. The case can be confirmed and the operation check of the regeneration switch 20 can be suitably performed. Furthermore, during the regeneration of the particulate filter 11 or the regeneration request of the particulate filter 11 can be performed in conjunction with the operation check of the regeneration switch 20 or the like.

  The particulate filter 11 is configured so that the operation of the notification lamp 19 can be ended by turning off the notification lamp 19 of the notification means when the operation switch is turned off or when the diesel engine 1 is started. Regardless of the over-collection state, the notification lamp 19 can be easily returned to the original state, and the operation check of the notification lamp 19 can be preferably completed.

  When it is determined whether or not the engine is stopped, if the operation means is in an ON state while the diesel engine 1 is driven, the particulate filter 11 is configured to be regenerated. The operation check of the notification lamp 19 of the notification means and the operation regeneration switch 20 and the regeneration of the particulate filter 11 are separated, so that the particulate filter 11 is not regenerated when the operation of the notification lamp 19 and the regeneration switch 20 is checked. can do.

  The exhaust emission control device of the present invention is not limited to the above-described embodiment, and the operating means may be other types such as a button type and a lever type in addition to the regeneration switch. In addition to the notification lamp, the means may be of other types such as a screen display, meter display, sound warning, etc. In addition, various changes can be made without departing from the scope of the present invention. is there.

It is the schematic which shows an example of the form which implements this invention. It is sectional drawing which shows the detail of the particulate filter of FIG. It is the perspective view which notched a part which shows the detail of the oxidation catalyst of FIG. It is a flowchart which shows an example which performs an operation | movement check of a notification lamp and an operation switch.

Explanation of symbols

1 Diesel engine (engine)
8 Exhaust gas 11 Particulate filter 14 Control device (forced regeneration means)
15 Fuel injection device (forced regeneration means)
19 Notification lamp (notification means)
20 Playback switch (operating means)

Claims (3)

A catalyst regeneration type particulate filter equipped in the middle of an exhaust pipe through which exhaust gas circulates, and a forced regeneration means for forcibly burning and removing the particulates collected by the particulate filter to regenerate the particulate filter And operating means provided in the driver's seat so as to operate the forced regeneration means, and notification means capable of receiving and displaying a regeneration request signal from the forced regeneration means,
When the operation means is turned on, it is determined whether or not the engine is stopped, the notification means is turned on in the power supply state under the engine stop, and the operation of the notification means can be checked. Exhaust gas purification device.   The exhaust emission control device according to claim 1, wherein the operation check of the notification means can be completed when the operation means is turned off or when the notification means is turned off by starting the engine.   3. The exhaust gas according to claim 1, wherein when determining whether or not the engine is stopped, the particulate filter can be regenerated if the operating means is in an ON state while the engine is driven. Purification equipment.

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