JP2012193701A - Particulate-matter processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a particulate-matter processing device that suitably executes aggregation of PM in exhaust gas by charging the PM while using an electrode.SOLUTION: The particulate-matter processing device is configured to aggregate particulate matter in exhaust gas. The device includes: an exhaust gas purifier provided in an exhaust passage of an internal combustion engine in order to purify exhaust gas discharged from the internal combustion engine; and a processing part that has an electrode, whose applied voltage can be changed, and allows a current to flow into a space, where the exhaust gas flowing out from the exhaust gas purifier flows through, between the electrode and the exhaust passage located on the downstream side of the exhaust gas purifier by a voltage, applied to the electrode, in the exhaust passage located on the downstream side of the exhaust gas purifier.

Description

  The present invention relates to a particulate matter processing apparatus having an electrode in an exhaust passage and aggregating particulate matter in the exhaust by applying a voltage to the electrode.

  A technique is known in which a discharge electrode is provided in an exhaust passage of an internal combustion engine, and corona discharge is generated from the discharge electrode to charge particulate matter (hereinafter also referred to as PM) to agglomerate PM (for example, (See Patent Document 1). By aggregating PM, as a result, the number of PM particles contained per unit volume can be reduced. Moreover, since the particle diameter of PM as a result of aggregation increases, for example, when a filter is provided on the downstream side of the discharge electrode, it becomes easy to collect PM by the filter.

JP 2006-194116 A

  An electrode is provided in the exhaust passage of the internal combustion engine, and by applying a voltage to the electrode, the PM in the exhaust gas flowing through the exhaust passage is charged and aggregated, thereby reducing the number of PM per unit volume contained in the exhaust gas. It can be reduced. This greatly contributes to reducing the environmental load caused by the number of PM particles. Here, the flow rate of the exhaust gas discharged from the internal combustion engine varies depending on the engine load of the internal combustion engine, etc., but the reason is that the inertial force of the PM increases as the exhaust flow rate increases. PM charge aggregation is difficult to be performed satisfactorily.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a particulate matter processing apparatus that suitably performs PM aggregation by charging PM in exhaust using an electrode.

  In the present invention, in order to solve the above-described problem, a processing unit for performing PM aggregation by charging PM in exhaust using an electrode is provided downstream of the exhaust purification device in the exhaust passage connected to the internal combustion engine. It was decided to be provided in the exhaust passage located on the side. By disposing the processing unit on the downstream side of the exhaust gas purification apparatus, exhaust with reduced flow velocity is caused to flow into the processing unit, and efficient PM aggregation is attempted.

  More specifically, the present invention relates to a particulate matter processing apparatus that agglomerates particulate matter in exhaust gas, and is provided in an exhaust passage of an internal combustion engine and purifies exhaust gas exhausted from the internal combustion engine. And an exhaust passage located on the downstream side of the exhaust purification device, and an electrode whose applied voltage can be changed, and the exhaust purification device between the electrode and the exhaust passage by the applied voltage to the electrode. And a processing section for passing an electric current through a space through which the exhaust gas flowing out passes.

In the particulate matter processing apparatus according to the present invention, by providing the processing unit, voltage application to the electrode is controlled in the exhaust passage, and the space between the electrode and the exhaust passage, that is, the space in which exhaust flows ( Hereinafter, the current flows in the “charging space”), and the PM in the exhaust is charged. As a result, PM aggregates due to electrostatic force, or charged PM is attracted to the exhaust passage side, and as a result, the PMs aggregate together. As a result, the particle size of the PM in the exhaust gas increases, It is possible to reduce the number of particles per unit volume contained.

  And in the said particulate matter processing apparatus, this process part is provided in the downstream of the exhaust gas purification apparatus for exhaust gas purification. In the exhaust gas purification device provided in the exhaust passage, it comes into contact with the exhaust gas to purify NOx and the like contained in the exhaust gas, and is a place where a physical and chemical reaction necessary for exhaust gas purification occurs. Therefore, although there is a slight difference depending on the specific mode of the exhaust purification device, the exhaust purification device can be a resistance to the flow of exhaust gas. Since the flow velocity is reduced as compared with the above, the inertial force of the PM contained therein can be reduced. Aggregation between PMs is realized on the balance between the electrostatic force (Coulomb force) acting between the PMs and the inertial force of the PMs. Therefore, if the PM inertial force is reduced by passing through the exhaust purification device, Therefore, the electrostatic force between the PMs is strengthened, and the aggregation of the PMs is promoted.

  Here, in the particulate matter processing device, the exhaust purification device has an exhaust purification catalyst group in which a plurality of exhaust purification catalysts for purifying exhaust discharged from the internal combustion engine are arranged in series, The processing unit may be provided further on the downstream side than the exhaust purification catalyst on the most downstream side in the exhaust purification catalyst group. As an exhaust purification device provided in the exhaust passage, an exhaust purification catalyst group formed so that exhaust flows sequentially into a plurality of exhaust purification catalysts depending on the purpose of exhaust purification may be employed. For example, an exhaust purification device may be formed by arranging in series an oxidation catalyst, a NOx catalyst for NOx purification, a filter carrying a predetermined exhaust purification catalyst, and the like. In this way, when the exhaust purification device is formed by the exhaust purification catalyst group, by disposing the processing unit further downstream of the exhaust purification catalyst located at the rearmost (most downstream side) of the group, Exhaust gas with a reduced flow rate can be effectively supplied to the processing unit, so that efficient PM aggregation is expected. The processing unit may be provided so as to be sandwiched between two catalysts constituting the exhaust purification catalyst group.

  Further, in the particulate matter treatment device, the exhaust passage downstream of the exhaust purification device is provided with a silencer that silences the exhaust sound of the exhaust gas flowing therethrough, and the processing unit is a part of the silencer. It may be formed as a part. In view of the fact that the silencer is a device that lowers the pressure of exhaust gas and reduces the flow velocity thereof, the processing unit is formed as a part of the silencer, in other words, the processing unit is included in the silencer. By forming the silencer as described above, exhaust gas having a reduced flow velocity is supplied to the processing unit itself, and efficient PM aggregation is expected.

  Moreover, when a silencer is provided similarly in the particulate matter treatment apparatus, the processing unit may be provided on the downstream side of the silencer. That is, a configuration is adopted in which the processing unit is arranged on the downstream side of the silencer so that the exhaust gas whose pressure is reduced and the flow velocity is reduced by the silencer is supplied to the processing unit thereafter. With this configuration, exhaust gas with a reduced flow rate is more reliably supplied, and efficient PM aggregation is expected.

  In the case described above, the processing unit itself can also exhibit a silencing function according to the shape and size of the exhaust passage of the processing unit. That is, the space in the processing section is also a charging space for charging the PM by emitting electrons from the electrodes, and can also be a silencing space for silencing if a decrease in the exhaust gas flow velocity can be expected due to the space. Therefore, by designing the respective capacities so that the removal frequency by the silencer for silencing and the removal frequency by the processing unit are different, in other words, the silencer and the processing unit cooperate to perform exhaust silencing. By designing to achieve, it is possible to reduce the capacity of the silencer. For example, if the silencer is designed to remove the low frequency region and the processing unit removes the high frequency region, the capacity of the entire device can be reduced compared to the case where the silencer itself removes both frequency regions. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the particulate matter processing apparatus which performs PM aggregation suitably by charging PM in exhaust gas using an electrode.

It is a figure which shows schematic structure of the particulate matter processing apparatus which concerns on the Example of this invention. It is a flowchart regarding the process which reduces the number of PM particle | grains in exhaust_gas | exhaustion performed with the particulate matter processing apparatus shown in FIG. It is the figure which showed an example of the map for calculating the number of PM particles from an engine speed and an engine load. It is the figure which showed an example of the map for calculating an applied voltage from the exhaust gas flow rate from an internal combustion engine, and the number of PM particles. It is a 2nd figure which shows schematic structure of the particulate matter processing apparatus which concerns on the Example of this invention. It is a 3rd figure which shows schematic structure of the particulate matter processing apparatus which concerns on the Example of this invention.

  Hereinafter, specific embodiments of the particulate matter processing apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a particulate matter processing apparatus 1 according to an embodiment of the present invention. The particulate matter processing apparatus 1 is provided, for example, in an exhaust passage 2 of a gasoline engine, or can be provided in an exhaust passage of a diesel engine. Regardless of whether it is provided in the exhaust passage of any internal combustion engine, the PM in the exhaust is charged by applying a voltage to the electrode 5 to promote the aggregation of the PM, thereby increasing the particle size of the PM particles in the exhaust. The accompanying number of particles can be reduced. Below, the detail of the particulate matter processing apparatus 1 is demonstrated.

  The particulate matter processing apparatus 1 includes a housing 3 whose both ends are connected to an exhaust passage 2. The material of the housing 3 is a stainless steel material. The housing 3 is formed in a hollow cylindrical shape having a diameter larger than that of the exhaust passage 2. Both ends of the housing 3 are formed in a tapered shape in which the cross-sectional area decreases as the distance from the end increases. In FIG. 1, the exhaust flows through the exhaust passage 2 in the direction of the arrow and flows into the housing 3. For this reason, the housing 3 may be a part of the exhaust passage 2. In this embodiment, the space inside the housing 3 is the above-described charging space.

  Here, the exhaust passage 2 and the housing 3 are connected via an insulating portion 4. The insulating part 4 is made of an electrical insulator. The insulating portion 4 is sandwiched between a flange 21 formed at the end of the exhaust passage 2 and a flange 31 formed at the end of the housing 3. The exhaust passage 2 and the housing 3 are fastened by bolts and nuts, for example. In addition, these bolts and nuts are also insulated so that electricity does not flow through these bolts and nuts. In this way, an electrically insulated state is formed between the exhaust passage 2 and the housing 3.

An electrode 5 is attached to the housing 3. The electrode 5 penetrates the side surface of the housing 3, extends from the side surface of the housing 3 toward the central axis of the housing 3, bends in the vicinity of the central axis, and upstream of the flow of exhaust gas, and is parallel to the central axis It extends toward the upstream side of the exhaust flow. For this reason, the end of the electrode 5 is located near the central axis of the housing 3. Further, an insulator 51 made of an electrical insulator is provided on the electrode 5 so that the electrode 5 and the housing 3 are in direct contact with each other so that electricity does not flow. The insulator 51 is located between the electrode 5 and the housing 3, and has a function of insulating electricity and fixing the electrode 5 to the housing 3. In this way, the electrode 5 is attached to the housing 3 via the insulator portion 51, so that the electrode 5 is positioned in the charging space in the housing 3.

  The electrode 5 is connected to the power source 6 via the power source side electric wire 52. The power source 6 can energize the electrode 5 and change the applied voltage. The power source 6 is connected to the control device 7 and the battery 8 through electric wires. The control device 7 controls the voltage that the power source 6 applies to the electrode 5.

  A ground side electric wire 53 is connected to the housing 3, and the housing 3 is grounded via the ground side electric wire 53. The ground side electric wire 53 is provided with a detection device 9 that detects a current passing through the ground side electric wire 53. For example, the detection device 9 detects a current by measuring a potential difference between both ends of a resistor provided in the middle of the ground-side electric wire 53. The detection device 9 is connected to the control device 7 via an electric wire. With such a configuration, the current detected by the detection device 9 is input to the control device 7.

  Note that an accelerator opening sensor 71, a crank position sensor 72, a temperature sensor 73, and an air flow meter 74 are connected to the control device 7. The accelerator opening sensor 71 outputs an electric signal corresponding to the amount of depression of the accelerator pedal by the driver of the vehicle equipped with the internal combustion engine to which the particulate matter processing device 1 is connected, and detects the engine load. The crank position sensor 72 detects the engine speed of the internal combustion engine. The temperature sensor 73 detects the temperature of the internal combustion engine by detecting the temperature of the coolant of the internal combustion engine or the temperature of the lubricating oil. The air flow meter 74 detects the intake air amount of the internal combustion engine.

  In the particulate matter processing apparatus 1 configured as described above, by applying a negative DC high voltage from the power source 6 to the electrode 5, electrons are emitted from the electrode 5, and charging between the electrode 5 and the housing 3 is performed. Current flows through the space. That is, electrons are emitted from the electrode 5 by making the potential of the electrode 5 lower than that of the housing 3. The electrons in the exhaust gas can be negatively charged by the electrons. Negatively charged PM moves due to Coulomb force and gas flow. When the PM reaches the housing 3, the electrons negatively charged with the PM flow through the housing 3 and flow to the outside through the installation-side electric wire 53. As a result, the PMs that have released electrons to the housing 3 are aggregated with each other to increase the particle diameter. Further, the aggregation of PM reduces the number of PM particles per unit volume in the exhaust gas. Thus, by applying a voltage to the electrode 5, the particle diameter of PM can be increased and the number of PM particles per unit volume in the exhaust gas can be reduced.

  In the present embodiment, the electrode 5 is bent toward the upstream side of the exhaust flow, but instead, it may be bent toward the downstream side. Here, when the electrode 5 is bent toward the upstream side of the exhaust flow as in the present embodiment, PM hardly adheres to the insulator portion 51. That is, since PM can be charged on the upstream side of the insulator portion 51, the PM moves toward the inner peripheral surface of the housing 3. For this reason, since PM colliding with the insulator part 51 decreases, it becomes difficult for PM to adhere to the insulator part 51. However, if the electrode 5 is bent toward the upstream side of the exhaust flow, the electrode 5 is easily deformed by receiving a force from the exhaust flow. For this reason, it is suitable when the electrode 5 is short. On the other hand, when the electrode 5 is bent toward the downstream side of the exhaust flow, PM is likely to adhere to the insulator portion 51, but the electrode 5 is not easily deformed even if a force is received from the exhaust flow. For this reason, durability and reliability are high and the electrode 5 can be lengthened.

Here, with respect to the particulate matter treatment apparatus 1 according to the present invention, an exhaust purification device 10 for purifying NOx and the like in the exhaust is provided in the exhaust passage 2, and the particulate matter treatment apparatus 1 is disposed downstream thereof. Has been. Specifically, the exhaust gas purification device 10 is installed in the exhaust passage 2 to which the upstream end of the housing 3 when connected to the exhaust flow is connected, and the exhaust gas passing through the exhaust gas purification device 10 is on the downstream side. It is configured to flow into the housing 3. The exhaust purification device 10 can be formed of various known exhaust purification catalysts or a plurality of exhaust purification catalysts in order to perform exhaust purification. For example, in order to remove NOx in the exhaust gas, an exhaust purification device 10 is formed by arranging an oxidation catalyst 11 upstream and an NOx occlusion reduction catalyst (NOx catalyst) 12 downstream in the exhaust flow. Also good. In this case, an addition valve 13 for adding fuel as a reducing agent is disposed upstream of the oxidation catalyst 11. As another specific example, a configuration in which a hydrolysis catalyst, a NOx selective reduction catalyst, and an oxidation catalyst are sequentially arranged from the upstream side along the exhaust flow may be applied to the exhaust purification device 10. In this case, an addition valve for adding urea as a reducing agent is arranged on the upstream side of the hydrolysis catalyst. The NOx occlusion reduction type catalyst 12 and the NOx selective reduction type catalyst in these specific forms are also referred to as underfloor catalysts because they are arranged under the floor of a vehicle equipped with an internal combustion engine. Since control for exhaust gas purification in each specific form is known, detailed description in this specification is omitted.

  By disposing the particulate matter treatment device 1 on the downstream side of the exhaust purification device 10 in this way, the exhaust discharged from the internal combustion engine first passes through the exhaust purification device 10 and then the housing 3 of the particulate matter treatment device 1. Flows in. The oxidation catalyst 11 and the NOx catalyst 12 that form the exhaust purification device 10 are generally configured such that a catalyst metal or the like is supported on a carrier member, and the exhaust gas flows into the catalyst to come into contact with the catalyst metal. A predetermined reaction necessary for exhaust purification occurs. Therefore, each catalyst forming the exhaust gas purification device 10 can be resistant to the exhaust gas, and the flow rate of the exhaust gas flowing into the housing 3 is lower than the exhaust gas flow rate when flowing into the exhaust gas purification device 10. As a result, the inertial force of the PM contained in the exhaust is reduced. Aggregation of PMs caused by voltage application to the electrode 5 is realized on the balance between the electrostatic force (Coulomb force) acting between the PMs and the inertial force of the PMs. When the inertial force is reduced, the electrostatic force between the PMs is relatively strengthened, and thus aggregation of the PMs is promoted. As a result, the process of reducing the number of PM particles can be performed more efficiently, so that the power required for the PM process in the exhaust gas can be suppressed.

  Here, the process of reducing the number of PM particles in the cooled exhaust gas will be described with reference to FIG. FIG. 2 is a flowchart showing a control flow of the applied voltage for the process of reducing the number of PM particles according to the present embodiment. This routine is repeatedly executed every predetermined time by the control device 7 in conjunction with the operation of the internal combustion engine. The control device 7 is substantially equivalent to a computer including a CPU, a memory, a hard disk, and the like, and the control program is executed there to execute processing according to the flowchart shown in FIG. 2 and other processing.

First, in the processing from S101 to S103, the number of PM particles (number / cm ³ ) contained in the exhaust gas is calculated. The number of PM particles is the number of PM particles per cubic centimeter. The number of PM particles is the number of PM particles discharged from the internal combustion engine, and is the number of PM particles before flowing into the housing 3. Since the number of PM particles is correlated with the engine speed, the engine load, and the temperature of the internal combustion engine (for example, the temperature of the lubricating oil or the temperature of the cooling water), the number of PM particles is calculated based on these values.

  For this reason, in S101, the engine speed and the engine load are acquired. The engine speed is detected by a crank position sensor 72, and the engine load is detected by an accelerator opening sensor 71. In S102, the temperature of the internal combustion engine is acquired. The temperature of the internal combustion engine is detected by a temperature sensor 73.

In S103, the number of PM particles is calculated. Here, FIG. 3 is a diagram showing an example of a map for calculating the number of PM particles from the engine speed and the engine load. A plurality of this relationship is stored in the controller 7 in accordance with the temperature of the internal combustion engine (FIG. 3 shows a map when the temperature of the internal combustion engine is 20 ° C.). Then, using the map corresponding to the temperature of the internal combustion engine detected in S102, the number of PM particles is obtained from the engine speed and the engine load. This map is prepared in advance by experiments or the like. Although the number of PM particles may be detected using such a map, a sensor for detecting the number of PM particles is attached to the exhaust passage 2 upstream of the housing 3, and the number of PM particles is directly measured by the sensor. It may be detected.

  Next, in S104, the applied voltage to the electrode 5 is calculated based on the number of PM particles calculated in S103. This applied voltage is a voltage that is first applied to the electrode 5 when the internal combustion engine is started and the exhaust gas starts flowing in the exhaust passage 2. Then, using the applied voltage calculated in S104 as an initial value, feedback control is performed so that the applied voltage is maximized within a range where no overcurrent occurs (processing in S105). Specifically, the voltage applied to the electrode 5 is feedback-controlled so that the current value detected by the detection device 9 does not exceed a predetermined threshold value. Here, the initial value of the applied voltage is set based on the map shown in FIG.

FIG. 4 is a diagram showing an example of a map for calculating the applied voltage (V) from the exhaust flow rate (g / sec) from the internal combustion engine and the number of PM particles (× 10 ⁵ particles / cm ³ ). . This map is prepared in advance by experiments or the like. Since the exhaust gas flow rate from the internal combustion engine has a correlation with the intake air amount of the internal combustion engine, it can be obtained based on the intake air amount detected by the air flow meter 74.

  Here, the smaller the exhaust flow rate flowing through the exhaust passage 2, the smaller the inertial force of the PM, so that the influence of electrostatic action becomes relatively large. For this reason, PMs tend to aggregate. Therefore, as the exhaust gas flow rate is smaller, the PMs are aggregated with a smaller applied voltage. In consideration of this point, in the map shown in FIG. 4, the applied voltage is reduced as the exhaust gas flow rate decreases. On the other hand, the larger the number of PM particles, the shorter the distance between the PM particles, so that the influence of electrostatic action becomes relatively large. Therefore, as the number of PM particles increases, PM aggregates with a smaller applied voltage. In consideration of this point, in the map shown in FIG. 4, the applied voltage is reduced as the number of PM particles is increased. The initial value of the applied voltage may be, for example, a voltage value at which the reduction rate of the number of PM particles becomes a predetermined value (for example, 40%), and the initial value of the applied voltage is defined in advance. It may be a value. This specified value can be a value with a margin so that no overcurrent occurs.

  In this way, by applying feedback control to the applied voltage to the electrode 5 as shown in FIG. 2, it is possible to make the applied voltage as high as possible without causing an overcurrent. Thereby, since aggregation of PM can be promoted more, the number of PM particles can be further reduced. In addition, as described above, since the particulate matter treatment device 1 is disposed on the downstream side of the exhaust purification device 10, the flow rate of the exhaust gas flowing into the housing 3 can be reduced. It will be realized efficiently.

  In the above-described embodiments, the exhaust purification device 10 is formed of a catalyst group composed of a plurality of exhaust purification catalysts. However, the exhaust purification device 10 formed from a single exhaust purification catalyst may be adopted. .

FIG. 5 shows a schematic configuration relating to the second embodiment of the particulate matter processing apparatus according to the present invention. Differences between the particulate matter processing apparatus 100 shown in FIG. 5 and the particulate matter processing apparatus 1 shown in FIG. 1 will be described. In the particulate matter processing apparatus 100 shown in FIG. 5, a detection device 9 that detects a current passing through the power supply side electric wire 52 is provided in the power supply side electric wire 52 between the power supply 6 and the electrode 5. In this way, by providing the detection device 9 on the power supply side electric wire 52, the insulating portion 4 shown in FIG.
Is not necessary. That is, even if electricity flows from the housing 3 to the exhaust passage 2 side, the detection device 9 can detect the current passing through the electrode 5. However, in general, since the power supply side electric wire 52 is thicker and longer than the ground side electric wire 53, the electric capacity is increased. Therefore, in the particulate matter processing apparatus 100 shown in FIG. 5, even if a strong discharge such as a corona discharge occurs, it is difficult to detect the pulse current compared to the particulate matter processing apparatus 1 shown in FIG.

  Therefore, for example, when the feedback control of the applied voltage shown in FIG. 2 is performed, if it is necessary to detect a current having a high frequency component such as a pulse current and reflect it in the feedback control, the particles shown in FIG. When the particulate matter treatment apparatus 1 is useful and there is no need for such, the particulate matter treatment apparatus 100 having the form shown in FIG. 5 may be employed.

  FIG. 6 shows a schematic configuration relating to the third embodiment of the particulate matter processing apparatus according to the present invention. Differences between the particulate matter processing apparatus 110 shown in FIG. 6 and the particulate matter processing apparatus 1 shown in FIG. 1 will be described. The particulate matter treatment device 110 shown in FIG. 6 is provided further downstream of an exhaust silencer (so-called muffler) 13 provided downstream of the exhaust purification device 10. Although not shown, the exhaust silencer 13 is configured to gradually reduce the exhaust pressure, and the flow rate of the exhaust also decreases as the pressure decreases. Therefore, as shown in FIG. 6, the housing 3 of the particulate matter processing device 110 is connected downstream of the exhaust silencer 13 to sufficiently reduce the exhaust flow velocity, and then the exhaust is treated with the particulate matter treatment. This is used for the process of reducing the number of PM particles by the apparatus 110. As a result, the reduction process is efficiently realized.

  Here, the charging space of the housing 3 of the particulate matter processing device 110 has a cross-sectional area larger than the cross-sectional area of the exhaust passage 2, and the housing 3 itself has a predetermined length along the flow of the exhaust gas. Therefore, the charging space in the housing 3 is expected to exhibit a silencing effect by lowering the exhaust pressure, as in the exhaust silencing device 13. Therefore, the size and shape of the housing 3 may be determined from the viewpoint of exhaust noise reduction in addition to the viewpoint of PM aggregation in the exhaust gas. Specifically, when the frequency of the exhaust sound to be removed by the exhaust silencer 13 is set to a low frequency region, the housing 3 is configured such that the remaining high frequency regions can be removed by the housing 3. The size and shape are determined. As a result, the frequency region to be achieved by the exhaust silencer 13 is narrowed, so that the capacity of the device 13 can be reduced.

  Further, instead of the embodiment shown in FIG. 6, the particulate matter processing device 110 itself may be configured to be included in the exhaust silencer 13. Since the particulate matter treatment device 110 is present inside the exhaust silencer 13, the exhaust gas whose pressure has been lowered by the device 13 and the flow velocity has been reduced is supplied to the particulate matter treatment device 110 side. Thus, the process of reducing the number of PM particles in the exhaust is efficiently performed. At this time, as the housing 3 of the particulate matter processing device 110, the housing of the exhaust silencer 13 may also be used. That is, the housing of the exhaust silencer 13 also defines a space for silencing and also partially defines a charging space.

DESCRIPTION OF SYMBOLS 1 .... Particulate matter processing device 2 .... Exhaust passage 3 .... Housing 4 .... Insulating part 5 .... Electrode 6 .... Power source 7 .... Control device 8 ··· Battery 9 ··· Detection device 10 ··· Exhaust gas purification device 11 ··· Oxidation catalyst 12 ··· NOx occlusion reduction catalyst 100 ··· Particulate matter treatment device 110 ··· ..Particulate matter treatment equipment

Claims (4)

A particulate matter processing apparatus for aggregating particulate matter in exhaust gas,
An exhaust purification device that is provided in an exhaust passage of the internal combustion engine and purifies exhaust exhausted from the internal combustion engine;
Exhaust gas flowing out of the exhaust gas purification device between the electrode and the exhaust gas passage by an applied voltage to the electrode in an exhaust gas passage located downstream of the exhaust gas purification device. A processing section for passing an electric current through a space through which
A particulate matter processing apparatus comprising: The exhaust purification device has an exhaust purification catalyst group in which a plurality of exhaust purification catalysts for purifying exhaust discharged from the internal combustion engine are arranged in series,
The processing section is provided further downstream than the exhaust purification catalyst on the most downstream side in the exhaust purification catalyst group,
The particulate matter processing apparatus according to claim 1. The exhaust passage on the downstream side of the exhaust purification device is provided with a silencer that silences the exhaust sound of the exhaust flowing therethrough,
The processing unit is formed as a part of the silencer.
The particulate matter processing apparatus according to claim 1 or 2. The exhaust passage on the downstream side of the exhaust purification device is provided with a silencer that silences the exhaust sound of the exhaust flowing therethrough,
The processing unit is provided on the downstream side of the silencer,
The particulate matter processing apparatus according to claim 1 or 2.

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