JP2006077626A - Exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device contributing environmental conservation by effectively capturing particulate matter in exhaust gas and improving regeneration efficiency of a filter by suppressing accumulation of particulate matter on the filter. <P>SOLUTION: This exhaust emission control device is provided with an exhaust pipe 10 and a filter 20 provided in the exhaust pipe 10 and captures particulate matter in exhaust gas flowing into the exhaust pipe 10 by the filter 20 to purify exhaust gas. The exhaust pipe 10 is provided with an upstream side hollow pipe 11, a downstream side hollow pipe 12 and a casing part 13 including a guide flow path communicating to the upstream side hollow pipe 11 and the downstream side hollow pipe 12 and guiding exhaust gas flowing from an upstream side to a downstream side. The filter 20 includes a first part 21 covering an upstream side space in the guide flow path of the casing body 13 and a second part 22 covering a downstream side space of the guide flow path, is constructed to rotate around a predetermined rotary shaft, and positions of the first part 21 and the second part 22 can be freely changed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exhaust emission control device.

  Conventionally, a diesel engine has been adopted as an internal combustion engine of an automobile or the like. The exhaust gas of the diesel engine contains particulate matter that causes environmental pollution. For this reason, a “particulate filter (hereinafter sometimes simply referred to as“ filter ”)” is arranged in the exhaust passage of a diesel engine, and the technology for collecting particulate matter in exhaust gas with this filter is now in practical use. Has been.

  By the way, when the filter as described above is used for a certain period, the particulate matter accumulates on the surface or inside of the filter and clogging occurs. Such clogging of the filter may increase the pressure loss of the exhaust passage of the engine and cause a decrease in acceleration performance of an automobile or the like. Therefore, the particulate matter deposited on the filter is burned with the heat of the exhaust gas. The filter is played back.

However, when the temperature of the exhaust gas is low, the particulate matter deposited on the filter cannot be sufficiently combusted, and the regeneration state of the filter may be insufficient. Therefore, in recent years, accumulation of particulate matter in the filter is prevented by providing a “switching valve (butterfly valve)” that alternately discharges exhaust gas from both the upstream side and the downstream side to the filter. A technique has been proposed (see, for example, Patent Document 1).
JP 2001-317339 A

  However, in the technique described in Patent Document 1, since the flow of exhaust gas is reversed at a time every predetermined time using a switching valve, the particulate matter is present on the filter within a predetermined time until the flow is reversed. There is a concern that the accumulated particulate matter will be separated at once when it is deposited and the flow is reversed and mixed again in the exhaust gas. Further, when the technique described in Patent Document 1 is adopted, the switching valve is likely to be deteriorated due to the pressure and temperature of the exhaust gas, so that there is a problem that it takes time and cost to periodically replace the switching valve.

  An object of the present invention is to exhaust gas purification that can effectively collect particulate matter in exhaust gas and contribute to environmental conservation, and can increase the regeneration efficiency of the filter by suppressing the accumulation of particulate matter in the filter Is to provide a device.

  In order to solve the above problems, the invention according to claim 1 includes an exhaust pipe and a filter provided in the exhaust pipe, and the particulate matter in the exhaust gas flowing into the exhaust pipe is In the exhaust gas purification apparatus that collects the exhaust gas and purifies the exhaust gas, the exhaust pipe includes an upstream hollow tube, a downstream hollow tube, the upstream hollow tube, and the downstream hollow tube. A housing having a guide channel that communicates and guides the exhaust gas that has flowed in from the upstream side to the downstream side, wherein the filter closes the upstream space of the guide channel, and the guide And a second portion that closes the downstream space of the flow path, and the position of the first portion and the second portion can be exchanged freely.

  According to the first aspect of the present invention, the exhaust pipe communicates with the upstream hollow tube and the downstream hollow tube and has a guide channel that guides the exhaust gas flowing in from the upstream side to the downstream side. Department. And the filter which has the 1st part which block | closes the upstream space of the guide flow path of this housing | casing part, and the 2nd part which block | closes the downstream space of a guide flow path is provided. Therefore, both the particulate matter in the exhaust gas flowing from the upstream side into the guide flow path of the housing part and the particulate matter in the exhaust gas flowing out from the guide flow path of the housing part to the downstream side. Can be collected effectively.

  In addition, the position of the first part and the second part of the filter can be exchanged freely, and when the particulate matter is deposited in the first part arranged in the upstream space of the guide flow path of the housing part, This first part can be moved to the downstream space of the guide channel (the position where the second part was disposed). Therefore, the particulate matter deposited on the first portion can be removed. In addition, even when particulate matter is deposited on the second portion after the second portion is moved to the upstream space of the guide channel (the position where the first portion is disposed), the second portion is moved again. The particulate matter deposited by moving to the downstream space of the guide channel can be removed. Therefore, the particulate matter deposited on the first and second portions of the filter can be effectively removed, and the regeneration efficiency of the filter can be increased.

  According to a second aspect of the present invention, in the exhaust emission control device according to the first aspect, the casing has a cylindrical space including an upstream space and a downstream space of the guide flow path, and the filter The cylindrical body having a circular end surface is arranged so as to close the cylindrical space of the casing portion, and is configured to rotate around a rotation axis passing through the center of the circular end surface, A portion divided by a plane including a rotation axis is formed as the first portion and the second portion.

  According to the second aspect of the present invention, the filter is a cylindrical body having a circular end surface, and is arranged so as to close the cylindrical space of the housing portion, and is centered on a rotation shaft passing through the center of the circular end surface. It is comprised so that it may rotate. Therefore, for example, the first portion (or the second portion) located in the upstream space of the housing portion by rotating the filter at a predetermined speed (successively rotating in a certain direction) around the rotation axis. The second part (or the first part) located in the downstream space of the housing portion can be continuously moved to the upstream side. As a result, the accumulation of particulate matter on the filter can be continuously suppressed, and the regeneration efficiency of the filter can be increased. Further, for example, by rotating the filter by 180 ° about a rotation axis at regular intervals, the first part (or the second part) located in the upstream space of the housing part is moved to the downstream side. The second part (or the first part) located in the downstream space of the body part can be moved upstream to periodically reverse the inflow / outflow direction of the exhaust gas to the filter. As a result, the particulate matter deposited on the filter can be removed at once.

  The invention according to claim 3 is the exhaust gas purification apparatus according to claim 2, wherein the pressure difference detecting means for detecting the difference between the pressure in the upstream hollow tube and the pressure in the downstream hollow tube, and the pressure difference Rotation control means for rotating the filter by a predetermined angle about the rotation shaft when the pressure difference detected by the detection means exceeds a predetermined threshold value.

  According to the third aspect of the present invention, when the difference between the pressure in the upstream hollow tube and the pressure in the downstream hollow tube exceeds a predetermined threshold value (that is, the fluid resistance of the filter increases and the pressure loss in the exhaust tube is reduced). When the predetermined threshold value is exceeded, the filter can be automatically rotated by a predetermined angle to reverse the inflow / outflow direction of the exhaust gas with respect to the filter. Therefore, the accumulation of particulate matter on the filter can be automatically suppressed.

  According to a fourth aspect of the present invention, in the exhaust emission control device according to the third aspect, the rotation control means causes the filter to be turned off when a pressure difference detected by the pressure difference detection means exceeds a predetermined threshold. It is characterized by being rotated 180 °.

  According to the fourth aspect of the present invention, when the difference between the pressure in the upstream hollow tube and the pressure in the downstream hollow tube exceeds a predetermined threshold value (that is, the fluid resistance of the filter increases and the pressure loss in the exhaust pipe is reduced). The filter can be automatically rotated 180 ° when a predetermined threshold is exceeded. Accordingly, the entire first portion (or second portion) of the filter located in the upstream space of the housing portion is moved downstream, and the second portion (first portion) of the filter located in the downstream space of the housing portion is moved. 1 part) The entire part can be moved upstream. As a result, the inflow / outflow direction of the exhaust gas to the filter can be reversed at once, and the particulate matter deposited on the filter can be removed at once.

  According to a fifth aspect of the present invention, in the exhaust emission control device according to the second aspect, the operating state detecting means for detecting the operating state of the engine, and the operating state detected by the operating state detecting means is a low speed operating state. And a rotation control means for rotating the filter by a predetermined angle about the rotation axis.

  According to the fifth aspect of the present invention, when the operation state detected by the operation state detecting means is the “low-speed operation state” (that is, the temperature of the exhaust gas in the exhaust pipe is lowered and the filter is clogged). The filter can be automatically rotated by a predetermined angle to reverse the inflow / outflow direction of the exhaust gas with respect to the filter. Therefore, the accumulation of particulate matter on the filter can be automatically suppressed.

  According to a sixth aspect of the present invention, in the exhaust emission control device according to any one of the second to fifth aspects, a rotation control means for continuously rotating the filter in a fixed direction is provided.

  According to the sixth aspect of the present invention, since the filter can be continuously rotated in a certain direction (that is, the filter is rotated), the first filter of the filter located in the upstream space of the housing portion can be used. The portion (or the second portion) can be continuously moved to the downstream side, and the second portion (or the first portion) of the filter located in the downstream space of the housing portion can be continuously moved to the upstream side. As a result, the accumulation of particulate matter on the filter can be continuously suppressed, and the regeneration efficiency of the filter can be increased.

  According to the present invention, the exhaust pipe is provided with the housing portion having the guide flow path for guiding the exhaust gas flowing from the upstream side to the downstream side, and the upstream space and the downstream space of the guide flow path of the housing portion. In order to provide a filter that blocks the exhaust gas, both the fine particles in the exhaust gas flowing into the housing part from the upstream side and the fine particles in the exhaust gas flowing out from the housing part to the downstream side are effectively collected. Can contribute to environmental conservation. In addition, the position of the first part of the filter disposed in the upstream space of the housing part and the second part of the filter disposed in the downstream space of the housing part can be freely exchanged. The particulate matter deposited on the filter can be effectively removed, and the regeneration efficiency of the filter can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an exhaust emission control device mounted on a vehicle driven by a diesel engine (hereinafter referred to as “diesel vehicle”) will be described.

[First embodiment]
First, the configuration of the exhaust emission control device according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the exhaust purification device includes an exhaust pipe 10 that circulates exhaust gas discharged from the diesel engine 1 and leads it to the muffler 2, a filter 20 provided inside the exhaust pipe 10, The upstream pressure sensor 30 and the downstream pressure sensor 40 for detecting the pressure on the upstream side and the downstream side, the ECU 50 for detecting the pressure loss in the exhaust pipe 10 and rotating the filter 20, and the like. The particulate matter in the exhaust gas flowing through the exhaust pipe 10 is collected by the filter 20 to purify the exhaust gas.

  As shown in FIGS. 1 and 2, the exhaust pipe 10 includes an upstream hollow pipe 11 provided on the upstream side (diesel engine 1 side) and a downstream hollow provided on the downstream side (muffler 2 side). A tube 12 and a housing portion 13 provided between the upstream hollow tube 11 and the downstream hollow tube 12 are provided.

  A portion near the downstream end of the upstream hollow tube 11 and a portion near the upstream end of the downstream hollow tube 12 are formed so as to be bent at substantially right angles as shown in FIGS. Has been. As shown in FIG. 1, the downstream end 11a of the upstream hollow tube 11 and the upstream end 12a of the downstream hollow tube 12 are connected (fixed) to the casing 13 so that the casing The upstream hollow tube 11 and the downstream hollow tube 12 are configured to communicate with each other through a flow path in the body portion 13.

  As shown in FIG. 1, the housing 13 includes a short cylindrical portion 13 a to which the upstream hollow tube 11 and the downstream hollow tube 12 are connected, and a hemispherical casing 13 b connected to the cylindrical portion 13 a. , And is configured. The end of the cylindrical portion 13a (the end opposite to the casing 13b) has a slightly larger diameter as shown in FIG. 1 (a), and the downstream end of the upstream hollow tube 11 is connected to this end. 11a and the upstream end 12a of the downstream hollow tube 12 are inserted, and both are connected in a state where the seal member 14 is used to provide airtightness.

  As shown in FIG. 1A, a shaft member 15 that is rotated by the power of a motor 60 that is driven and controlled by the ECU 50 is inserted into the internal space (cylindrical space) of the cylindrical portion 13 a of the housing portion 13. Yes. As shown in FIG. 1B, a partition plate 16 that bisects the internal space of the filter 20 is fixed to the shaft member 15, so that the partition plate 16 and the filter 20 rotate together with the shaft member 15. It has become.

  A portion of the shaft member 15 extending from the housing portion 13 to the motor 60 is covered with a shaft cover 17 as shown in FIG. The shaft cover 17 is fixed between the upstream hollow tube 11 and the downstream hollow tube 12 and does not rotate together with the shaft member 15. A seal member 14 is disposed between the shaft cover 17 and the end portion 16 a of the partition plate 16, and exhaust gas flowing in from the upstream side flows downstream from the gap between the end portion 16 a of the partition plate 16 and the shaft cover 17. To prevent leakage.

  As shown in FIG. 1A, a heater unit 18 that raises the temperature of exhaust gas flowing from the upstream hollow tube 11 is provided in the upstream space in the cylindrical portion 13 a of the housing portion 13. . The heater unit 18 is controlled by the ECU 50, and when the temperature of the exhaust gas is low, the ECU 50 automatically controls the heater unit 18 to raise the temperature of the exhaust gas, thereby accumulating on the surface or inside of the filter 20. The particulate matter is burned and the regeneration of the filter 20 is promoted.

  The casing 13b of the housing part 13 is for making U-turn the exhaust gas flowing into the cylindrical part 13a of the housing part 13 from the upstream side and guiding it to the downstream side. The exhaust gas guide flow path is formed by the upstream space in the cylindrical portion 13a, the internal space of the casing 13b, and the downstream space in the cylindrical portion 13a.

  The filter 20 collects particulate matter in the exhaust gas flowing in the housing portion 13 and is a short cylindrical body having a circular end face as shown in FIG. The filter 20 has an outer diameter substantially equal to the inner diameter of the cylindrical portion 13a of the housing portion 13, and is disposed so as to close the internal space (cylindrical space) of the cylindrical portion 13a. The internal space of the filter 20 is divided into two parts by the partition plate 16 as shown in FIG. 1B, and one of the two parts (first part) 21 is arranged in the upstream space of the housing part 13, The other part (second part) 22 is arranged in the downstream space of the housing part 13.

  In addition, the filter 20 is configured to rotate together with the shaft member 15 and the partition plate 16 about a rotation axis passing through the center of the circular end surface. For this reason, the first portion 21 of the filter 20 disposed in the upstream space of the housing portion 13 is disposed downstream, and the second portion 22 of the filter 20 disposed in the downstream space of the housing portion 13 is disposed upstream. Each side. That is, the position of the first part 21 and the second part 22 of the filter 20 can be exchanged freely. The rotation speed and rotation timing of the filter 20 are controlled by the ECU 50.

  Inside the filter 20, as shown in FIG. 1B, a plurality of cross-sectional rectangular channels 23 formed by thin partition walls are provided. The partition walls forming the rectangular channel 23 are made of ceramic such as cordierite or heat-resistant metal powder, and the surface thereof is coated with a carrier such as γ-alumina. And on this carrier, “noble metal catalyst” such as Pt, Pd, Cu and the like, and when oxygen is present in the surrounding area, oxygen is taken in and retained, while when the surrounding oxygen concentration is lowered, the retained oxygen is in the form of active oxygen. “Active oxygen release agent” such as K, Na, Li, etc. released in the above is supported.

  The upstream pressure sensor 30 detects the pressure in the upstream hollow tube 11, and the downstream pressure sensor 40 detects the pressure in the downstream hollow tube 12. Information relating to the pressure detected by the upstream pressure sensor 30 and the downstream pressure sensor 40 is input to the ECU 50 and used for rotation control of the filter 20.

  The ECU 50 includes a memory, a CPU, and the like that record various control programs and control data, and integrally controls various devices such as the diesel engine 1 and the exhaust purification device. As shown in FIG. 1A, the ECU 50 includes a pressure difference detection means 51 for detecting a difference between the pressure detected by the upstream pressure sensor 30 and the pressure detected by the downstream pressure sensor 40, and the pressure difference. And a rotation control unit 52 that drives the motor 60 to rotate the filter 20 in the housing unit 13 when the pressure difference detected by the detection unit 51 exceeds a predetermined threshold value.

  The rotation control means 52 of the ECU 50 can appropriately control the rotation direction and rotation speed of the filter 20. For example, when the pressure difference detected by the pressure difference detection unit 51 exceeds a predetermined threshold, the rotation control unit 52 rotates the filter 20 by 180 ° in the direction of arrow A in FIG. it can. The rotation control means 52 can also rotate the filter 20 at a predetermined speed (continuously rotating in a certain direction) regardless of the pressure difference detected by the pressure difference detection means 51, and the rotation control in the present invention. It also functions as a means.

  In the exhaust gas purification apparatus according to the present embodiment described above, the exhaust pipe 10 communicates with the upstream side hollow pipe 11 and the downstream side hollow pipe 12 and guides the exhaust gas flowing in from the upstream side to the downstream side. A housing portion 13 having a guide channel is provided, and a filter 20 that closes the upstream space and the downstream space of the guide channel is provided in the housing portion 13. Therefore, the particulate matter in the exhaust gas flowing from the upstream side into the guide flow path of the housing part 13, and the particulate matter in the exhaust gas flowing out from the guide flow path of the housing part 13 to the downstream side, Both can be collected effectively.

  Further, in the exhaust purification apparatus according to the present embodiment described above, the filter 20 is a columnar body having a circular end face so as to block the internal space (cylindrical space) of the cylindrical portion 13a of the housing portion 13. It is arrange | positioned and it is comprised so that it may rotate centering on the rotating shaft which passes along the center of a circular end surface. Then, the rotation control means 52 of the ECU 50 can continuously rotate the filter 20 in a certain direction (that is, rotate the filter 20).

  Accordingly, the first portion 21 (or the second portion 22) of the filter 20 located in the upstream space in the cylindrical portion 13a of the housing portion 13 is positioned downstream and in the downstream space in the cylindrical portion 13a. The second portion 22 (or the first portion 21) of the filter 20 that has been placed can be continuously moved upstream. As a result, accumulation of particulate matter in the filter 20 can be continuously suppressed, and the regeneration efficiency of the filter 20 can be increased.

  In the exhaust gas purification apparatus according to the present embodiment described above, the difference between the pressure in the upstream hollow tube 11 and the pressure in the downstream hollow tube 12 exceeds a predetermined threshold (that is, the filter). When the fluid resistance of 20 increases and the pressure loss in the exhaust pipe 10 exceeds a predetermined threshold value), the rotation control means 52 of the ECU 50 can automatically rotate the filter 20 by 180 °.

  Accordingly, the entire first portion 21 (or the second portion 22) of the filter 20 located in the upstream space in the cylindrical portion 13a of the housing portion 13 is positioned downstream and in the downstream space in the cylindrical portion 13a. The entire second portion 22 (or the first portion 21) of the filter 20 that has been used can be moved upstream. As a result, the inflow / outflow direction of the exhaust gas with respect to the filter 20 can be reversed at once, and the particulate matter deposited on the filter 20 can be removed at once.

[Second Embodiment]
Next, the configuration of the exhaust emission control device according to the second embodiment of the present invention will be described with reference to FIG.

  The exhaust emission control device according to the present embodiment is obtained by changing the configuration of the ECU 50 of the exhaust emission control device according to the first embodiment and the positions of the shaft member 15 and the motor 60. This is substantially the same as the first embodiment. For this reason, only the changed configuration and position will be described, and the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment.

  In the present embodiment, as shown in FIG. 3, a motor 60 is disposed on the casing 13 b side of the casing 13 that constitutes the exhaust pipe 10. Further, a through hole is formed in the top portion of the casing 13b of the housing portion 13, and as shown in FIG. 3, the shaft member 15 that is rotationally driven by the motor 60 is inserted into the casing 13b from the through hole. It has become. The filter 20 disposed inside the cylindrical portion 13 a of the housing portion 13 rotates together with the shaft member 15 by the power of the motor 60.

  Further, as shown in FIG. 3, the ECU 50 according to the present embodiment includes the number of revolutions of the diesel engine 1 detected by the engine speed sensor 70 and the accelerator opening detected by the accelerator opening sensor 80. Based on this, an operation state detecting means 53 for detecting the operation state of the diesel vehicle is provided. Then, the rotation control means 52 of the ECU 50 in the present embodiment drives the motor 60 based on the operation state detected by the operation state detection means 53, and is arranged inside the cylindrical portion 13a of the housing portion 13. The filter 20 is rotated.

  The rotation control means 52 of the ECU 50 can appropriately control the rotation direction and rotation speed of the filter 20. For example, the rotation control unit 52 is clogged in the filter 20 when the operation state detected by the operation state detection unit 53 is the “low-speed operation state” (that is, the temperature of the exhaust gas in the exhaust pipe 10 decreases). The filter 20 is rotated 180 °.

  In the exhaust gas purification apparatus according to the present embodiment described above, when the operation state of the diesel vehicle detected by the operation state detection unit 53 is the “low speed operation state”, the rotation control unit 52 of the ECU 50 is the filter 20. Can be automatically rotated 180 ° to reverse the inflow / outflow direction of the exhaust gas with respect to the filter 20. Therefore, the accumulation of particulate matter on the filter 20 can be automatically suppressed.

  In the above embodiment, the vicinity of the ends of the upstream hollow tube 11 and the downstream hollow tube 12 constituting the exhaust pipe 10 (portions connected to the housing portion 13) are bent at substantially right angles. However, the shapes of the upstream hollow tube 11 and the downstream hollow tube 12 can be appropriately determined according to the position of the motor 60, the position of the diesel engine, the position of the muffler, and the like. Moreover, the cross-sectional shape and cross-sectional area of the upstream side hollow tube 11 and the downstream side hollow tube 12 are not specifically limited.

  Moreover, in the above embodiment, although the example which closed the edge part of the cylindrical part 13a by connecting the hemispherical casing 13b to the cylindrical part 13a of the housing | casing part 13 was shown, it does not necessarily show the hemispherical casing 13b. Is not necessary, and any member can be used as long as it can form a “guide channel” that guides exhaust gas flowing into the cylindrical portion 13a from the upstream side and passing through the cylindrical portion 13a to the downstream side.

  In the first embodiment, an example in which the motor 50 is driven and controlled by the ECU 50 based on the pressure difference in the exhaust pipe 10 to rotate the filter 20 is shown. In the second embodiment, Although the example in which the filter 20 is rotated by driving the motor 60 with the ECU 50 based on the operation state of the diesel vehicle has been shown, a configuration in which the filter 20 is manually rotated can also be adopted.

  For example, when the pressure difference in the exhaust pipe 10 exceeds a predetermined threshold, or when the operation state of the diesel vehicle is the “low-speed operation state”, a notification means (lamp) that notifies the passenger of the diesel vehicle to that effect And a rotating means for manually rotating the filter 20 are provided. Then, based on the notification from the notification means, the occupant rotates the filter 20 using the rotation means to reverse the inflow / outflow direction of the exhaust gas with respect to the filter 20. Even when such a configuration is adopted, particulate matter accumulation in the filter 20 can be suppressed.

  Further, in the above-described embodiment, the housing portion 13 is fixed to the upstream hollow tube 11 and the downstream hollow tube 12 of the exhaust pipe 10, and the filter is disposed inside the cylindrical portion 13 a of the housing portion 13. Although an example in which only 20 is rotated is shown, a configuration in which the filter 20 is fixed to the housing 13 and the housing 13 and the filter 20 are integrally rotated may be employed.

  Moreover, in the above embodiment, while the housing | casing part 13 comprised from the cylindrical part 13a and the hemispherical casing 13b was employ | adopted and the column-shaped filter 20 was employ | adopted, the housing | casing part was shown. The shapes of 13 and the filter 20 are not limited to this.

(A) is explanatory drawing for demonstrating the structure of the exhaust gas purification apparatus which concerns on the 1st Embodiment of this invention, (b) is sectional drawing of the BB part of (a). It is a perspective view at the time of seeing the exhaust gas purification apparatus which concerns on the 1st Embodiment of this invention from the casing side of a housing | casing part. It is explanatory drawing for demonstrating the structure of the exhaust gas purification apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exhaust pipe 11 Upstream hollow tube 12 Downstream hollow tube 13 Housing | casing part 20 Filter 21 1st part 22 2nd part 51 Pressure difference detection means 52 Rotation control means (rotation control means)
53 Operating state detection means

Claims (6)

In an exhaust gas purification apparatus comprising an exhaust pipe and a filter provided in the exhaust pipe, and collecting particulate matter in the exhaust gas flowing into the exhaust pipe with the filter to purify the exhaust gas.
The exhaust pipe is
An upstream hollow tube;
A downstream hollow tube;
A casing having a guide channel that communicates with the upstream hollow tube and the downstream hollow tube and guides the exhaust gas flowing in from the upstream side to the downstream side, and
The filter is
A first portion that closes the upstream space of the guide channel;
A second portion for closing the downstream space of the guide flow path,
An exhaust emission control device characterized in that the position of the first part and the second part can be exchanged freely. The housing portion is
A cylindrical space including an upstream space and a downstream space of the guide channel,
The filter is
The cylindrical body having a circular end face is disposed so as to close the cylindrical space of the casing portion, and is configured to rotate around a rotation axis passing through the center of the circular end face. The exhaust emission control device according to claim 1, wherein a portion divided into two planes including a moving axis is formed as the first portion and the second portion. Pressure difference detection means for detecting a difference between the pressure in the upstream hollow tube and the pressure in the downstream hollow tube;
A rotation control means for rotating the filter by a predetermined angle around the rotation axis when the pressure difference detected by the pressure difference detection means exceeds a predetermined threshold;
The exhaust emission control device according to claim 2, further comprising: The rotation control means includes
The exhaust emission control device according to claim 3, wherein when the pressure difference detected by the pressure difference detection means exceeds a predetermined threshold value, the filter is rotated 180 °. Comprising an operating state detecting means for detecting the operating state of the engine;
A rotation control means for rotating the filter by a predetermined angle about the rotation axis when the operation state detected by the operation state detection means is a low-speed operation state;
The exhaust emission control device according to claim 2, further comprising:   The exhaust emission control device according to any one of claims 2 to 5, further comprising a rotation control unit that continuously rotates the filter in a predetermined direction.

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