Exhaust gas purification device

Abstract

To provide an exhaust gas purification device which can further reduce a PM discharge amount at an initial stage of the start of use.SOLUTION: An exhaust gas purification device 1 includes a first air discharge path 51 and a second air discharge path 52 connected in parallel with each other and connected to an air discharge pipe 18 at a downstream side of a GPF 20B. At an initial state of the GPF 20B, the first air discharge path 51 communicates with a tail pipe 56 via a sub-filter 53 for collecting and removing PM, and after the start of use of the GPF 20B, the sub-filter 53 is clogged by the collected PM to block the communication with the tail pipe 56. At an initial state of the GPF 20B, the second air discharge path 52 is closed by a liquid (water) 57, and after the start of use of the GPF 20B, the sub-filter 53 is clogged by the PM to increase a pressure damage on the sub-filter 53 and increase the discharge pressure, and a discharge of the liquid (water) 57 and / or evaporation of the liquid (water) 57 allows a communication with the tail pipe 56.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an exhaust gas purification device. [Background technology]

[0002] In recent years, with the spread of direct injection (in-cylinder injection) in gasoline engines, regulations on PM (Particulate Matter) for gasoline engines have been strengthened (more specifically, in addition to PM weight regulations, PN (Particulate Number) regulations that regulate the number of particles in PM have been introduced). In order to comply with these PM and PN regulations, a GPF (Gasoline Particulate Filter) that captures and removes PM contained in engine exhaust has been proposed (see, for example, Patent Document 1).

[0003] GPFs and Diesel Particulate Filters (DPFs) (hereinafter collectively referred to as "particulate filters") become clogged with trapped PM when used continuously. Therefore, when a particulate filter has captured a certain amount of PM, it undergoes a regeneration process in which the trapped (accumulated) PM is burned and removed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-222028 Summary of the Invention [Problem to be solved by the invention]

[0005] The PM capture efficiency of a particulate filter varies depending on the amount of PM captured (amount of accumulation). More specifically, in the early stages of capture (when the amount of PM accumulated is small), the particulate filter has large filter openings and a low PM capture efficiency. As PM capture (accumulation) progresses, the filter openings gradually become smaller and the PM capture efficiency increases.

[0006] Furthermore, because particulate filters are usually installed directly below the engine or under the floor near the engine, they are unable to capture PM that may be generated in new vehicles and is caused by processing oil remaining inside the exhaust pipe located downstream of the particulate filter. For this reason, vehicles equipped with particulate filters emit a relatively large amount of PM in the early stages of use (when the vehicle is new).

[0007] The present invention has been made to solve the above problems, and aims to provide an exhaust purification device equipped with a particulate filter that captures and removes PM, which can further reduce PM emissions in the early stages of use (when the vehicle is new). [Means for solving the problem]

[0008] An exhaust purification device according to one embodiment of the present invention is an exhaust purification device that includes a particulate filter that captures and removes particulate matter and purifies exhaust gas emitted from an engine, and includes a first exhaust passage and a second exhaust passage that are connected in parallel to each other and connected to an exhaust passage downstream of the particulate filter, and is characterized in that in the initial state of the particulate filter, the first exhaust passage communicates with the tailpipe via an auxiliary filter that captures and removes particulate matter, and after use of the particulate filter begins, the auxiliary filter becomes clogged with the trapped particulate matter, thereby cutting off communication with the tailpipe, and the second exhaust passage is blocked by liquid in the initial state of the particulate filter, and after use of the particulate filter begins, the auxiliary filter becomes clogged with particulate matter, causing an increase in pressure loss in the auxiliary filter and an increase in exhaust pressure, resulting in the discharge of liquid and / or evaporation of the liquid, thereby connecting the first exhaust passage to the tailpipe.

[0009] According to an exhaust gas purification device according to one aspect of the present invention, in the initial state of the particulate filter (at the start of use when the PM capture rate is low), the first exhaust passage communicates with the tailpipe via the auxiliary filter, and the second exhaust passage is blocked by liquid (blocked from communication with the tailpipe). This allows exhaust gas to flow through the first exhaust passage, allowing the auxiliary filter to capture and remove PM that was not (could not) be captured and removed by the particulate filter. Furthermore, because the auxiliary filter is located downstream of the particulate filter, it can also capture and remove PM that may be generated downstream of the particulate filter in a new vehicle. Subsequently (after use begins), as the engine continues to operate, the auxiliary filter becomes clogged with trapped PM, causing the first exhaust passage to become clogged. Meanwhile, the second exhaust passage becomes connected to the tailpipe as the auxiliary filter becomes clogged with PM, increasing pressure loss in the auxiliary filter and causing an increase in exhaust pressure, resulting in the discharge of liquid and / or evaporation of the liquid. Meanwhile, at this time, the PM capture rate of the particulate filter is high. Therefore, after the PM is trapped and removed by the particulate filter, the exhaust gas can be discharged from the tail pipe through the second exhaust passage. [Effects of the Invention]

[0010] According to the present invention, in an exhaust purification device equipped with a particulate filter that captures and removes PM, it is possible to further reduce the amount of PM emissions in the early stages of use (when the vehicle is new). [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing the configuration of an exhaust gas purification device according to an embodiment and an engine to which the exhaust gas purification device is applied; [Figure 2] 2 is a cross-sectional view showing the configuration of a muffler that constitutes the exhaust purification device according to the embodiment. FIG. [Figure 3] 1A and 1B are a front view and a plan view showing the configuration of a muffler that constitutes an exhaust purification device according to an embodiment. [Figure 4] 3A to 3C are a cross-sectional view, a front view, and a plan view showing the configuration of a muffler that constitutes an exhaust purification device according to a first modified example. [Figure 5] 5A to 5C are a cross-sectional view, a front view, and a plan view showing the configuration of a muffler that constitutes an exhaust purification device according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Unless otherwise specified, the same or corresponding parts in the drawings will be designated by the same reference numerals. Furthermore, the same elements in each drawing will be designated by the same reference numerals, and redundant explanations will be omitted.

[0013] First, the configuration of an exhaust purification device 1 according to an embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is a diagram showing the configuration of the exhaust purification device 1 and an engine 10 to which the exhaust purification device 1 is applied. Fig. 2 is a cross-sectional view showing the configuration of a muffler 50 that constitutes the exhaust purification device 1. In Fig. 2, the upper part shows the state at the start of use (initial state), and the lower part shows the state after traveling a predetermined distance. Fig. 3 is a front view and a plan view (cross-sectional view taken along line III-III in Fig. 2) showing the configuration of the muffler 50 that constitutes the exhaust purification device 1.

[0014] The engine 10 is, for example, a horizontally opposed four-cylinder gasoline engine. The engine 10 is a direct-injection engine that directly injects fuel into the cylinders. In the engine 10, air is drawn in through an air cleaner 16, throttled by an electronically controlled throttle valve (hereinafter simply referred to as a "throttle valve") 13 provided in an intake pipe 15, and then passes through an intake manifold 11 and is drawn into each cylinder formed in the engine 10. The amount of air drawn in through the air cleaner 16 is detected by an air flow meter 14 disposed between the air cleaner 16 and the throttle valve 13. A vacuum sensor 30 is disposed inside a collector (surge tank) that constitutes the intake manifold 11, and detects the pressure within the intake manifold 11 (intake manifold pressure). The throttle valve 13 is also provided with a throttle opening sensor 31 that detects the opening of the throttle valve 13.

[0015] The cylinder head is formed with an intake port 22 and an exhaust port 23 for each cylinder (only one bank is shown in FIG. 1). Each intake port 22 and exhaust port 23 is provided with an intake valve 24 and an exhaust valve 25 that open and close the intake port 22 and exhaust port 23, respectively. A variable valve timing mechanism 26 is disposed between the intake camshaft that drives the intake valve 24 and the intake cam pulley. The variable valve timing mechanism 26 rotates the intake cam pulley and the intake camshaft relatively to continuously change the rotational phase (displacement angle) of the intake camshaft with respect to the crankshaft 10a, thereby advancing or retarding the valve timing (opening / closing timing) of the intake valve 24. The variable valve timing mechanism 26 variably sets the opening and closing timing of the intake valve 24 according to the engine operating conditions.

[0016] Similarly, a variable valve timing mechanism 27 is disposed between the exhaust camshaft and the exhaust cam pulley, which rotates the exhaust cam pulley and the exhaust camshaft relatively to continuously change the rotational phase (displacement angle) of the exhaust camshaft with respect to the crankshaft 10a, thereby advancing or retarding the valve timing (opening / closing timing) of the exhaust valve 25. The variable valve timing mechanism 27 variably sets the opening / closing timing of the exhaust valve 25 according to the engine operating state.

[0017] An injector 12 that injects fuel into the cylinder is attached to each cylinder of the engine 10. The injector 12 directly injects fuel pressurized by a high-pressure fuel pump (not shown) into the combustion chamber of each cylinder.

[0018] The cylinder head of each cylinder is also fitted with a spark plug 17 that ignites the air-fuel mixture, and an igniter-integrated coil 21 that applies high voltage to the spark plug 17. In each cylinder of the engine 10, the air-fuel mixture of intake air and fuel injected by the injector 12 is ignited by the spark plug 17 and combusted. Exhaust gas after combustion is discharged through an exhaust pipe 18 (corresponding to an exhaust passage in the claims).

[0019] An air-fuel ratio sensor 19 is attached downstream of the collecting portion of the exhaust pipe 18 and upstream of the exhaust purification catalyst 20A. As the air-fuel ratio sensor 19, a linear air-fuel ratio sensor (LAF sensor) is used, which can output a signal corresponding to the oxygen concentration and unburned gas concentration in the exhaust (i.e., a signal corresponding to the air-fuel ratio of the mixture) and can linearly detect the air-fuel ratio.

[0020] An exhaust purification catalyst 20A is disposed downstream of the LAF sensor 19. The exhaust purification catalyst 20A is a three-way catalyst (TWC) that simultaneously oxidizes hydrocarbons (HC) and carbon monoxide (CO) in the exhaust and reduces nitrogen oxides (NOx), thereby purifying harmful gas components in the exhaust into harmless carbon dioxide (CO2), water vapor (H2O), and nitrogen (N2).

[0021] A GPF (gasoline particulate filter) 20B that captures and removes PM (particulate matter) contained in the exhaust gas is disposed downstream of the exhaust purification catalyst 20A. Specifically, HC, CO, and NOx are purified by the exhaust purification catalyst 20A, and then PM is collected and removed by passing through the GPF 20B. The GPF 20B is preferably a so-called closed-type (wall-flow type) GPF, in which a heat-resistant ceramic such as cordierite is formed into a honeycomb structure and multiple cells serving as gas flow paths are sealed at the end faces so that the inlet and outlet sides are alternately arranged. As described above, the GPF 20B has large filter openings at the beginning of collection (when the amount of PM accumulation is small), resulting in a low PM collection efficiency. As PM collection (accumulation) progresses, the filter openings gradually become smaller, resulting in a higher PM collection efficiency.

[0022] A muffler (silencer) 50 that reduces exhaust noise is connected to the rear end of the exhaust pipe 18 (i.e., downstream of the GPF 20B). The muffler 50 has a plurality of partition walls or the like arranged inside a housing formed, for example, in the shape of a rectangular parallelepiped, a cylinder, or an elliptical cylinder, and reduces exhaust noise by expanding the exhaust gas in stages or by repeatedly causing pressure waves to interfere with each other, thereby lowering the pressure and temperature of the exhaust gas. Note that a pre-muffler that mainly reduces high frequency noise may be provided upstream of the muffler (main muffler) 50. The muffler 50 will be described in detail later.

[0023] An exhaust gas recirculation device (hereinafter referred to as an "EGR (Exhaust Gas Recirculation) device") 40 is provided in the exhaust pipe 18, which recirculates a portion of the exhaust (exhaust gas) emitted from the engine 10 to the intake manifold 11 of the engine 10. The EGR device 40 has an EGR pipe 41 that connects the exhaust pipe 18 of the engine 10 with the intake manifold 11, and an EGR valve 42 that is installed in the EGR pipe 41 and adjusts the amount of exhaust gas recirculation (EGR flow rate). The opening degree (EGRSTP) of the EGR valve 42 is controlled by an ECU 70, which will be described later, in accordance with the operating state of the engine 10.

[0024] In addition to the air flow meter 14, LAF sensor 19, vacuum sensor 30, and throttle opening sensor 31 described above, a cam angle sensor 32 for identifying the cylinders of the engine 10 is attached near the camshaft of the engine 10. A crank angle sensor 33 for detecting the rotational position of the crankshaft 10a is attached near the crankshaft 10a of the engine 10. A timing rotor 33a having, for example, 34 protrusions with two teeth missing, formed at 10° intervals, is attached to the end of the crankshaft 10a. The crank angle sensor 33 detects the rotational position of the crankshaft 10a by detecting the presence or absence of the protrusions on the timing rotor 33a. The cam angle sensor 32 and the crank angle sensor 33 may be, for example, electromagnetic pickup types.

[0025] These sensors are connected to the ECU 70. In addition, various sensors are also connected to the ECU 70, such as a water temperature sensor 34 that detects the temperature of the coolant for the engine 10, an oil temperature sensor 35 that detects the temperature of the lubricating oil, an accelerator sensor 36 that detects the amount of depression of the accelerator pedal, i.e., the amount of operation of the accelerator pedal, and a vehicle speed sensor 37 that detects the speed of the vehicle.

[0026] The ECU 70 is configured to include a microprocessor that performs calculations, an EEPROM that stores programs and the like for causing the microprocessor to execute various processes, a RAM that stores various data such as calculation results, a backup RAM in which the stored contents are maintained by a battery or the like, and an input / output I / F, etc. The ECU 70 also includes an injector driver that drives the injector 12, an output circuit that outputs an ignition signal, and a motor driver that drives the electric motor 13a that opens and closes the electronically controlled throttle valve 13, etc.

[0027] The ECU 70 identifies the cylinder from the output of the cam angle sensor 32, and determines the rotational angular velocity and engine speed from the output of the crank angle sensor 33. The ECU 70 also acquires various information such as the intake air amount, intake pipe negative pressure, accelerator pedal opening, air-fuel ratio of the mixture, and water temperature and oil temperature of the engine 10 based on the detection signals input from the various sensors described above. The ECU 70 then comprehensively controls the engine 10 by controlling the fuel injection amount, ignition timing, and various devices such as the throttle valve 13 and the EGR valve 42 based on the acquired information.

[0028] In particular, the muffler 50 constituting the exhaust purification device 1 equipped with the GPF 20B, which has a low PM capture rate in the early stages of use (when the vehicle is new), has the function of further reducing PM emissions in the early stages of use (when the vehicle is new).

[0029] Therefore, the muffler 50 has therein a first exhaust passage 51 and a second exhaust passage 52 connected in parallel to each other. Therefore, the first exhaust passage 51 and the second exhaust passage 52 are connected to the exhaust pipe 18 downstream of the GPF 20B. In this embodiment, the first exhaust passage 51 and the second exhaust passage 52 are common up to just before the sub-filter 53 described below (that is, the first exhaust passage 51 and the second exhaust passage 52 are separated just before the sub-filter 53).

[0030] A sub-filter 53 is disposed on the first exhaust passage 51. As the sub-filter 53, a filter capable of capturing and removing PM, similar to the GPF 20B, is used. The size and other details of the sub-filter 53 will be described later.

[0031] In the initial state of the GPF 20B (when the GPF 20B starts to be used), the first exhaust passage 51 communicates with the tail pipe 56 via the sub-filter 53. After the GPF 20B starts to be used, as the engine 10 continues to operate, PM accumulates in the sub-filter 53, clogging the sub-filter 53 with PM, causing the first exhaust passage 51 to become blocked and its communication with the tail pipe 56 to be cut off.

[0032] In the initial state of the GPF 20B (at the start of use of the GPF 20B), the second exhaust passage 52 is blocked by a partition wall 501, which is provided above a liquid storage section 58 (described later) and extends vertically downward and in the vehicle width direction, and by the liquid 57 (i.e., communication with the tailpipe 56 is blocked). Here, water, which is harmless and easily evaporates in the environment, is preferably used as the liquid 57. After the start of use of the GPF 20B, the sub-filter 53 becomes clogged with PM, which increases the pressure loss of the sub-filter 53 and causes an increase in exhaust pressure. As a result, the liquid (water) 57 is discharged and / or evaporates, and the second exhaust passage 52 communicates with the tailpipe 56. The second exhaust passage 52 is an original passage (path) within the muffler 50.

[0033] Furthermore, an inclined plate 54 having a cutout 541 formed therein for discharging liquid (water) 57 is disposed at the bottom of muffler 50 on the vehicle rear side, and is inclined, for example, so that the vehicle front side is lower than the vehicle rear side. Note that cutout 541 is formed, for example, in the shape of a triangle with its apex at the vehicle front side. Furthermore, a liquid storage portion 58 for storing liquid (water) 57 is formed at the bottom of muffler 50 on the side of inclined plate 54 (the vehicle front side in this embodiment).

[0034] When the sub-filter 53 becomes clogged with PM, the pressure loss of the sub-filter 53 increases, and the exhaust pressure rises, the liquid level of the liquid (water) 57 stored in the liquid storage section 58 is pushed vertically downward, causing the liquid (water) 57 to be pushed up onto the inclined plate 54 and discharged (drained) through the notch 541. In this way, the liquid (water) 57 is discharged and the liquid level (water level) drops, thereby clearing the blockage of the second exhaust passage 52 and connecting the second exhaust passage 52 to the tailpipe 56 (see the lower part of FIG. 2).

[0035] Here, after muffler 50 is mounted on the vehicle body, liquid (water) 57 is injected using a hose from tail pipe 56 protruding from the rear end surface of muffler 50. Therefore, inclined plate 54 disposed below tail pipe 56, groove 55 is formed so as to extend in the longitudinal direction of the vehicle, for guiding liquid (water) 57 injected from tail pipe 56 to liquid storage section 58, avoiding notch 541.

[0036] Incidentally, at a predetermined timing (for example, when a predetermined mileage is reached or when a predetermined engine operating time has elapsed) from the initial state of the GPF 20B (after the start of use of the GPF 20B), the exhaust passage is switched from the first exhaust passage 51 to the second exhaust passage 52. Therefore, the size (for example, diameter, thickness, fineness, etc.) and collection performance of the sub-filter 53 to be used, the amount of liquid (water) 57 to be injected, the inclination angle of the inclined plate 54, the shape, size, and arrangement of the notch 541, the vertical length of the partition wall 501, etc. are set (adjusted) in consideration of, for example, the relationship between the amount of PM generated, the pressure loss in the sub-filter 53, and the exhaust pressure, the relationship between the exhaust pressure and the liquid level (water level), and the relationship between the exhaust temperature and the evaporation amount of the liquid (water) 57.

[0037] More specifically, the size and collection performance of the above-mentioned sub-filter 53, the amount of liquid (water) 57, the inclination angle of the inclined plate 54, the shape, size and arrangement of the notch 541, and the vertical length of the partition wall 501 are set (adjusted) so that the exhaust passage can be switched in, for example, about 1 to 5 driving cycles (50 to 500 km).In addition, the above parameters are set taking into consideration that if the sub-filter 53 becomes clogged, the exhaust pressure will not abnormally increase.

[0038] With the above-described configuration, in the initial state of GPF 20B (at the start of use (new vehicle) when the PM capture rate is low), first exhaust passage 51 is in communication with tailpipe 56 via sub-filter 53, and second exhaust passage 52 is blocked by liquid (water) 57. Therefore, exhaust gas flows through first exhaust passage 51, and PM not captured and removed by GPF 20B is captured and removed by sub-filter 53, and then discharged from tailpipe 56 (see the dashed-dotted arrow in the upper diagram of FIG. 2). Furthermore, because sub-filter 53 is located within muffler 50 (downstream of GPF 20B), PM that may be generated downstream of GPF 20B when the vehicle is new is also captured and removed.

[0039] Then, thereafter (after the start of use), as the operation of the engine 10 progresses, PM accumulates in the sub-filter 53, clogging the sub-filter 53 with PM and blocking the first exhaust passage 51. Meanwhile, the second exhaust passage 52 communicates with the tailpipe 56 as the sub-filter 53 becomes clogged with PM, increasing the pressure loss in the sub-filter 53 and raising the exhaust pressure. Liquid (water) 57 is discharged from the notch 541 of the inclined plate 54 and / or as the liquid (water) 57 evaporates. At this time, the PM collection efficiency of the GPF 20B is also high. Therefore, after the PM is collected and removed by the GPF 20B, the exhaust gas flows through the second exhaust passage 52, which has a lower pressure loss than the sub-filter 53, and is discharged from the tailpipe 56 (see the dashed arrow in the lower diagram of FIG. 2).

[0040] As described above in detail, according to this embodiment, in the initial state of GPF 20B (at the start of use (new vehicle) when the PM capture rate is low), first exhaust passage 51 is connected to tailpipe 56 via sub-filter 53, and second exhaust passage 52 is blocked by liquid (water) 57. This allows exhaust gas to flow through first exhaust passage 51, allowing PM that was not (could not be) captured and removed by GPF 20B to be captured and removed by sub-filter 53. In addition, because sub-filter 53 is disposed within muffler 50 (downstream of GPF 20B), it can also capture and remove PM that may be generated downstream of GPF 20B when the vehicle is new. As a result, it is possible to further reduce PM emissions in the initial state of use (new vehicle).

[0041] After that (after the start of use), as the operation of the engine 10 progresses, the sub-filter 53 becomes clogged with PM, causing the first exhaust passage 51 to become blocked. Meanwhile, the second exhaust passage 52 becomes connected to the tailpipe 56 as the sub-filter 53 becomes clogged with PM, causing an increase in pressure loss in the sub-filter 53, resulting in a rise in exhaust pressure, and as a result of the discharge of liquid (water) 57 and / or the evaporation of liquid (water) 57. Meanwhile, at that time, the PM collection efficiency of the GPF 20B is high. Therefore, after the PM is collected and removed by the GPF 20B as usual, the exhaust can be discharged from the tailpipe 56 through the second exhaust passage 52 (after the exhaust noise has been reduced).

[0042] According to this embodiment, the size of the sub-filter 53 and the amount of liquid (water) 57 are set so that the exhaust passage is switched from the first exhaust passage 51 to the second exhaust passage 52 when a predetermined timing (a predetermined traveling distance or a predetermined operating time, etc.) is reached from the initial state of the GPF 20B (when use of the GPF 20B begins). Therefore, when a predetermined timing (a predetermined traveling distance or a predetermined operating time, etc.) is reached from the initial state of the GPF 20B (when use of the GPF 20B begins), the exhaust passage can be switched accurately from the first exhaust passage 51 to the second exhaust passage 52.

[0043] According to this embodiment, by arranging the first exhaust passage 51 and the second exhaust passage 52 inside the muffler 50, the sub-filter 53 can be disposed on the most downstream side (downstream end) of the exhaust pipe 18. Furthermore, by incorporating the first exhaust passage 51 (sub-filter 53) and the second exhaust passage 52 (inclined plate 54) inside the muffler 50, it is possible to reduce space, costs, and the like compared to providing a separate, new dedicated housing, piping, and the like.

[0044] According to this embodiment, the inclined plate 54 having the notches 541 formed therein is disposed in the muffler 50, and when the secondary filter 53 becomes clogged with PM, the pressure loss of the secondary filter 53 increases, and the exhaust pressure rises, the liquid level of the liquid (water) 57 is pushed vertically downward, so that the liquid is pushed up onto the inclined plate 54 and discharged through the notches 541. Therefore, when the secondary filter 53 becomes clogged with PM, the pressure loss of the secondary filter 53 increases, and the exhaust pressure rises, the liquid (water) 57 can be accurately discharged (drained) through the notches 541, that is, the liquid level (water level) can be lowered and the blockage of the second exhaust passage 52 can be cleared.

[0045] According to this embodiment, grooves 55 are formed in inclined plate 54 to guide liquid (water) 57 injected from tail pipe 56 protruding from muffler 50 to liquid storage portion 58, avoiding notch 541. Therefore, when liquid (water) 57 is injected from tail pipe 56, liquid (water) 57 can be accurately guided to liquid storage portion 58 (i.e., liquid (water) 57 does not leak from notch 541).

[0046] (First Modification) In the above embodiment, the tail pipe 56 and the groove 55 of the inclined plate 54 are disposed in the center of the muffler 50 in the vehicle width direction, and the notches 541 are formed on both sides of the inclined plate 54 (groove 55). However, as shown in FIG. 4, for example, the tail pipe 56 and the groove 55B of the inclined plate 54B may be disposed on the right (or left) side of the muffler 50B in the vehicle width direction, and the notch 541B may be formed on the left (or right) side of the inclined plate 54B in the vehicle width direction. Here, FIG. 4 is a cross-sectional view, a front view, and a plan view showing the configuration of the muffler 50B constituting the exhaust purification device according to the first modified example. Note that other configurations are the same as or similar to those of the above embodiment (the muffler 50 described above), and therefore detailed description thereof will be omitted here.

[0047] This modification can also achieve the same effect as the above embodiment, that is, it is possible to further reduce PM emissions in the early stages of use (when the vehicle is new).

[0048] (Second Modification) Furthermore, instead of the cutouts 541 in the inclined plate 54, all or part of the inclined plate 54 may be a punched mesh 541C (a punched inclined plate 54C with a plurality of holes), as shown in Fig. 5. Here, Fig. 5 is a cross-sectional view, a front view, and a plan view showing the configuration of a muffler 50C constituting an exhaust purification device according to a second modified example. Note that other configurations are the same as or similar to those of the first modified example, and therefore detailed description thereof will be omitted here.

[0049] This modification can also achieve the same effects as the above embodiment. That is, it is possible to further reduce PM emissions in the early stages of use (when the vehicle is new). In addition, this modification can also improve the sound deadening effect of the punched mesh 541C.

[0050] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible. For example, although the above embodiment has been described using an example in which the present invention is applied to a direct injection engine (gasoline engine) 10 equipped with a GPF 20B, the present invention can also be applied to, for example, a diesel engine equipped with a DPF.

[0051] In addition, in the above embodiment, the first exhaust passage 51 and the second exhaust passage 52 are common up to just before the sub-filter 53, but for example, the first exhaust passage 51 and the second exhaust passage 52 may be separated further upstream.

[0052] Furthermore, the shape of the notch 541 of the inclined plate 54 is not limited to a triangle, and may be formed into a different shape depending on requirements and the like.

[0053] In addition, in order to prevent liquid (water) from being discharged from the notch 541 of the inclined plate 54 when going uphill or during sudden acceleration, the configuration may further include a plate (shielding plate) that has a weight and automatically slides toward the rear of the vehicle when going uphill or during sudden acceleration, thereby blocking part or all of the notch 541 of the inclined plate 54. [Explanation of symbols]

[0054] 1 Exhaust gas purification device 10 Engine 18 Exhaust pipe (exhaust passage) 20A Exhaust Gas Cleaning Catalyst (TWC) 20B GPF 40 Exhaust Gas Recirculation System 41 EGR piping 42 EGR valve 50, 50B, 50C muffler (silencer) 501 Bulkhead 51 First exhaust passage 52 Second exhaust passage 53 Secondary Filter 54, 54B, 54C inclined plate 541, 541B notch 541C Punching Mesh 55, 55B groove 56 Tailpipe 57 Liquid (water) 58 Liquid storage section 70 ECU

Claims

1. An exhaust purification device that includes a particulate filter that captures and removes particulate matter and purifies exhaust gas emitted from an engine, a first exhaust passage and a second exhaust passage connected in parallel to each other and connected to an exhaust passage downstream of the particulate filter, The first exhaust passage is In an initial state, the particulate filter communicates with a tail pipe via a sub-filter that captures and removes particulate matter, After the particulate filter starts to be used, the secondary filter becomes clogged with trapped particulate matter, thereby blocking communication with the tail pipe, The second exhaust passage is In an initial state, the particulate filter is clogged with liquid, After the particulate filter starts to be used, the secondary filter becomes clogged with particulate matter, causing an increase in pressure loss in the secondary filter, resulting in an increase in exhaust pressure, and the liquid is discharged and / or evaporates, causing the liquid to communicate with the tailpipe. An exhaust gas purification device characterized by:

2. 2. The exhaust purification device according to claim 1, wherein the size of the sub-filter and the amount of the liquid are set so that the exhaust passage is switched from the first exhaust passage to the second exhaust passage when a predetermined timing is reached from the initial state of the particulate filter.

3. 3. The exhaust purification device according to claim 2, wherein the first exhaust passage and the second exhaust passage are disposed in a muffler that is interposed on the exhaust passage and that reduces exhaust noise.

4. a slanted plate having a notch formed therein and disposed at an angle within the muffler; 4. The exhaust purification device according to claim 3, wherein when the secondary filter becomes clogged with particulate matter, the pressure loss in the secondary filter increases, and the exhaust pressure rises, the liquid level is pushed vertically downward, causing the liquid to be pushed up onto the inclined plate and discharged through the notch.

5. The exhaust purification device according to claim 4, characterized in that a groove is formed in the inclined plate to guide the liquid injected from the tail pipe protruding from the muffler to a liquid storage section arranged on the bottom surface of the muffler and to the side of the inclined plate, avoiding the notch.

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