Exhaust Gas Purification Device

Abstract

This exhaust gas purification device comprises a filter provided to an exhaust flow path connected to an engine, a rotary vane provided downstream of the filter in the exhaust flow path, and a control device having one or more processors and one or more memories connected to the processors. On the basis of the rotational speed of the rotary vane, the processors execute processes including at least one of an estimation process for estimating the amount of particulate matter deposited in the filter, or a regeneration process for regenerating the filter.

Description

[Technical field]

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

[0002] Exhaust gas discharged from an engine contains particulate matter such as soot. For this reason, vehicles are provided with a DPF (Diesel Particulate Filter) or a GPF (Gasoline Particulate Filter) as a filter to remove particulate matter. Such filters remove particulate matter from exhaust gas by capturing the particulate matter in holes formed in the filter. With continued use, the filter becomes clogged with particulate matter.

[0003] Therefore, as shown in, for example, Patent Document 1, a technique for estimating the amount of particulate matter deposited on a filter based on the pressure difference between before and after the filter is widely used. In this technique, when the pressure difference increases to a predetermined pressure threshold, it is estimated that the amount of particulate matter deposited on the filter has increased to a predetermined amount threshold, and a regeneration process is performed on the filter. The regeneration process is a process in which air is sent to the filter to combust the particulate matter and remove it from the filter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-59817 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the pressure difference across the filter varies depending on not only the amount of particulate matter deposited on the filter but also its distribution, and therefore, in the filter, the pressure difference may be below the pressure threshold even when the amount of particulate matter deposited is equal to or greater than the amount threshold, or the pressure difference may be equal to or greater than the pressure threshold even when the amount of particulate matter deposited is less than the amount threshold.

[0006] In the case of a deposition distribution in which the amount of particulate matter is equal to or greater than the amount threshold but the differential pressure is less than the pressure threshold, when the differential pressure reaches the pressure threshold, the amount of particulate matter has already far exceeded the amount threshold. Therefore, if regeneration processing is performed when the differential pressure reaches the pressure threshold, there is a risk that the particulate matter will be abnormally combusted.

[0007] On the other hand, in the case of a deposition distribution in which the differential pressure is equal to or greater than the pressure threshold even when the amount of particulate matter deposition is less than the amount threshold, the amount of particulate matter deposition is still less than the amount threshold even when the differential pressure reaches the pressure threshold, and therefore, even if the filter is not clogged, the regeneration process is unnecessarily performed when the differential pressure reaches the pressure threshold.

[0008] Therefore, if the deposition amount is estimated based on the pressure difference between before and after the filter, there is a problem that the regeneration process cannot be performed at an appropriate timing.

[0009] In view of the above problems, the present invention has an object to provide an exhaust gas purification device that is capable of executing a regeneration process at an appropriate timing based on a criterion other than the differential pressure before and after the filter. [Means for solving the problem]

[0010] In order to solve the above problems, an exhaust gas purification device according to one embodiment of the present invention comprises: A filter provided in an exhaust passage connected to the engine; a rotary vane provided downstream of the filter in the exhaust passage; A control device having one or more processors and one or more memories coupled to the processors; Equipped with The processor, Passively rotated by the flow of exhaust gas through the exhaust passage A process including at least one of an estimation process for estimating an amount of particulate matter accumulated on the filter based on the rotation speed of the rotary vanes and a regeneration process for regenerating the filter is executed. Effect of the Invention

[0011] According to the present invention, it is possible to execute the regeneration process at an appropriate timing based on a criterion other than the differential pressure across the filter. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing an example of a functional configuration of a control device according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a first diagram illustrating the relationship between the deposition distribution of particulate matter in a filter according to one embodiment of the present invention and the flow of exhaust gas passing through the filter. [Figure 4] FIG. 4 is a second diagram illustrating the relationship between the deposition distribution of particulate matter in a filter according to one embodiment of the present invention and the flow of exhaust gas passing through the filter. [Diagram 5] FIG. 5 is a third diagram illustrating the relationship between the deposition distribution of particulate matter in a filter according to one embodiment of the present invention and the flow of exhaust gas passing through the filter. [Figure 6] FIG. 6 is a diagram showing the relationship between the operating time of the engine according to one embodiment of the present invention and the rotation speed of the rotor blades. [Figure 7] FIG. 7 is a flowchart showing a process flow of a method for regenerating filter 220 according to an embodiment of the present invention. [Figure 8]FIG. 8 is a block diagram showing an example of a functional configuration of a control device according to the first modified example. [Figure 9] FIG. 9 is a flowchart showing a process flow of the filter regenerating method according to the first modified example. [Figure 10] FIG. 10 is a flowchart showing a process flow of the filter regenerating method according to the second modified example. [Figure 11] FIG. 11 is a flowchart showing a process flow of the filter regenerating method according to the third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The specific dimensions, materials, numerical values, etc. shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0014] Fig. 1 is a schematic diagram showing the configuration of a vehicle 100 according to an embodiment of the present invention. In Fig. 1, dashed arrows indicate the flow of signals.

[0015] As shown in FIG. 1, a vehicle 100 according to this embodiment includes an engine 110, an intake passage 120, an exhaust passage 130, a muffler 140, and an exhaust gas purification device 200.

[0016] Vehicle 100 includes engine 110 as a drive source. Engine 110 is a gasoline engine. However, the vehicle according to the present invention is not limited to this example, and may be, for example, a hybrid vehicle including a motor as a drive source in addition to engine 110.

[0017] An intake manifold is connected to an intake port of the engine 110. A collecting portion of the intake manifold is connected to an intake passage 120. The intake passage 120 is formed of, for example, a pipe.

[0018] An exhaust manifold is connected to the exhaust port of the engine 110. An exhaust flow path 130 is connected to a collection portion of the exhaust manifold. The exhaust flow path 130 is formed of, for example, a pipe. Exhaust gas exhausted from the engine 110 flows through the exhaust flow path 130. Hereinafter, the upstream side in the flow direction of the exhaust gas may simply be referred to as "upstream". Also, the downstream side in the flow direction of the exhaust gas may simply be referred to as "downstream".

[0019] An exhaust gas purification device 200 and a muffler 140 are provided in the exhaust flow path 130. The exhaust gas purification device 200 is provided between the engine 110 and the muffler 140 in the exhaust flow path 130. The exhaust gas purification device 200 purifies the exhaust gas exhausted from the engine 110. The exhaust gas purified by the exhaust gas purification device 200 is exhausted to the outside through the muffler 140.

[0020] Next, the configuration and functions of the exhaust gas purification device 200 will be described in detail.

[0021] [Exhaust gas purification device 200] As shown in FIG. 1, the exhaust gas purification device 200 includes a catalytic device 210 , a filter 220 , a rotor blade 230 , a motor 240 , and a control device 250 .

[0022] The catalytic device 210 is provided between the engine 110 and the muffler 140 in the exhaust flow path 130. The catalytic device 210 includes, for example, a three-way catalyst. The three-way catalyst is, for example, a catalytic metal such as platinum (Pt), palladium (Pd), or rhodium (Rh). The catalytic device 210 removes hydrocarbons, carbon monoxide, and nitrogen oxides from the exhaust gas discharged from the engine 110.

[0023] The filter 220 is provided downstream of the catalytic device 210 in the exhaust flow path 130. In other words, the filter 220 is provided between the catalytic device 210 and the muffler 140 in the exhaust flow path 130. The filter 220 has, for example, a cylindrical shape. The filter 220 is disposed coaxially with the exhaust flow path 130a connected to the upstream side of the filter 220.

[0024] In this embodiment, the filter 220 is, for example, a gasoline particulate filter (GPF). The filter 220 captures particulate matter contained in the exhaust gas. The particulate matter includes, for example, soot. The filter 220 is, for example, a wall-flow type.

[0025] The rotating vanes 230 are provided downstream of the filter 220 in the exhaust passage 130. In this embodiment, the rotating vanes 230 are configured to be passively rotatable by the flow of exhaust gas through the exhaust passage 130. The rotating vanes 230 can also be actively rotated by a motor 240, which will be described later.

[0026] In this embodiment, the rotation axis of the rotating vanes 230 is coaxial with the central axis of the cylindrical filter 220, for example. That is, the central axis of the exhaust passage 130a, the central axis of the filter 220, and the rotation axis of the rotating vanes 230 are arranged on the same straight line. This increases the correlation between the rotation speed of the rotating vanes 230 rotated by the exhaust gas that has passed through the filter 220 and the deposition distribution and deposition amount of particulate matter deposited on the filter 220, making it possible to estimate the deposition amount with higher accuracy.

[0027] The motor 240 rotates the rotating impeller 230. In this embodiment, when a regeneration process of the filter 220 is performed, the motor 240 is connected to the rotating impeller 230 and rotates the rotating impeller 230. By rotating the rotating impeller 230 by the motor 240, the flow rate of the gas flowing through the filter 220 can be increased.

[0028] Furthermore, when the regeneration process of the filter 220 is not being performed, the motor 240 is disconnected from the rotating blades 230, and the rotating blades 230 can freely rotate due to the flow of the exhaust gas. Furthermore, when the regeneration process of the filter 220 is not being performed, the operation of the motor 240 is stopped.

[0029] The control device 250 has one or more processors 252 and one or more memories 254 connected to the processors 252. The processor 252 includes, for example, a CPU (Central Processing Unit). The memory 254 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a storage element that stores programs and computation parameters used by the CPU. The RAM is a storage element that temporarily stores data such as variables and parameters used in processing executed by the CPU.

[0030] The control device 250 communicates with each device (for example, the engine 110, the rotor blades 230, the motor 240, etc.) provided in the vehicle 100. The communication between the control device 250 and each device is realized, for example, by using CAN (Controller Area Network) communication.

[0031] Fig. 2 is a block diagram showing an example of a functional configuration of the control device 250 according to an embodiment of the present invention. For example, as shown in Fig. 2, the control device 250 has a signal acquisition unit 260, an accumulation amount estimation unit 262, an engine control unit 264, a motor control unit 266, and a storage unit 270. Note that various processes including the processes described below performed by the signal acquisition unit 260, the accumulation amount estimation unit 262, the engine control unit 264, and the motor control unit 266 may be executed by the processor 252. In detail, the various processes are executed by the processor 252 executing a program stored in the memory 254.

[0032] The signal acquisition unit 260 acquires the rotation speed (number of revolutions) of the rotating vanes 230. In this embodiment, the signal acquisition unit 260 acquires the rotation speed of the rotating vanes 230 when the regeneration process for the filter 220 is not executed and the flow rate of the exhaust gas flowing through the exhaust passage 130 is in a steady state. The steady state is a state in which the flow rate of the exhaust gas is substantially constant, for example, a state in which the rate of change of the flow rate is within ±5%. The steady state is a state in which the flow rate of the exhaust gas is substantially constant, for example, during warm-up operation of the engine 110.

[0033] The accumulation amount estimation unit 262 executes an estimation process to estimate the accumulation amount of particulate matter in the filter 220, based on the change in the rotation speed of the rotating blades 230. Here, the change in the rotation speed of the rotating blades 230 refers to the change over time in the rotation speed of the rotating blades 230 when the rotation speed changes over time while the engine 110 is in operation.

[0034] Figures 3 to 5 are diagrams illustrating the relationship between the accumulation distribution of particulate matter in filter 220 according to one embodiment of the present invention and the flow of exhaust gas passing through filter 220. In Figures 3 to 5, the one-sided diagonal hatched area indicates an area where particulate matter has not accumulated, and the cross-hatched area indicates an area where particulate matter has accumulated. Also, in Figures 3 to 5, the arrows indicate the flow of exhaust gas.

[0035] As described above, the central axis of exhaust flow path 130a and the central axis of filter 220 are aligned on the same straight line. Therefore, in the first state in which almost no particulate matter has accumulated in any region of filter 220 as shown in Fig. 3, exhaust gas supplied to filter 220 from exhaust flow path 130a travels straight through central region 220a including the central axis of filter 220. Filter 220 in the first state is a brand new filter 220 or a filter 220 immediately after a regeneration process has been performed.

[0036] The particulate matter is trapped in the area of ​​the filter 220 through which the exhaust gas has passed. Thus, the particulate matter first accumulates in the central area 220a of the filter 220.

[0037] On the other hand, the magnitude of pressure loss in filter 220 depends on the amount of particulate matter deposited. Specifically, the greater the amount of particulate matter deposited in filter 220, the greater the pressure loss. For this reason, exhaust gas supplied to filter 220 from exhaust flow path 130a flows preferentially through areas with a smaller amount of deposition than areas with a larger amount of deposition. Therefore, as shown in Figs. 3 to 5, from the first state, the area where particulate matter deposits expands from central region 220a of filter 220 toward peripheral region 220b as the operating time of engine 110 elapses.

[0038] Next, the flow of exhaust gas passing through the filter 220 and the rotation speed of the rotor blades 230 will be described.

[0039] 3, in the first state in which almost no particulate matter has accumulated on the filter 220, the exhaust gas flowing through the exhaust passage 130a travels in a substantially straight line, passes through the central region 220a of the filter 220, and reaches the rotary vanes 230. Therefore, the exhaust gas mainly hits the rotary vanes 230 at the rotary shaft (central portion) and the vicinity of the rotary shaft.

[0040] Then, as the operation time of engine 110 elapses from the first state, the amount of particulate matter deposited on filter 220 increases, and filter 220 transitions from the first state to the second state.

[0041] As shown in Fig. 4, when the filter 220 is in the second state, particulate matter is deposited in the central region 220a including the central axis of the filter 220. As described above, the region where the particulate matter is deposited has a large pressure loss. Therefore, the exhaust gas flows preferentially through the outer peripheral region 220b where no particulate matter is deposited, rather than through the central region 220a where the particulate matter is deposited. Therefore, the exhaust gas mainly hits the outer peripheral portion of the rotating blade 230 and the vicinity of the outer peripheral portion.

[0042] The torque T for rotating the rotary vane 230 depends on the force F acting on the rotary vane 230 and the distance L from the position of the rotary vane 230 where the force F acts to the rotary shaft (T=F×L). The flow rate of the exhaust gas acting on the rotary vane 230 corresponds to the above-mentioned "force F", and the distance from the position where the exhaust gas hits the rotary vane 230 to the rotary shaft corresponds to the above-mentioned "distance L". Therefore, the rotation speed of the rotary vane 230 depends on the flow rate of the exhaust gas acting on the rotary vane 230 and the distance from the position where the exhaust gas hits the rotary vane 230 to the rotary shaft. Therefore, when the flow rate of the exhaust gas is approximately constant, the rotation speed of the rotary vane 230 is higher when the exhaust gas hits the outer periphery of the rotary vane 230 than when the exhaust gas hits the center of the rotary vane 230. Therefore, when the filter 220 is in the second state, the rotation speed of the rotary vane 230 is higher than when it is in the first state.

[0043] Then, as the operation time of engine 110 elapses from the second state, the amount of particulate matter deposited on filter 220 further increases, and filter 220 transitions from the second state to the third state.

[0044] As shown in Fig. 5, when the filter 220 is in the third state, particulate matter is deposited in all areas of the filter 220. Therefore, the exhaust gas passes through the entire filter 220. Therefore, the exhaust gas hits the entire rotating blade 230 almost evenly. Then, when the filter 220 is in the third state, the rotation speed of the rotating blade 230 is smaller than that in the second state. Also, when the filter 220 is in the third state, the rotation speed of the rotating blade 230 is greater than that in the first state.

[0045] 6 is a diagram showing the relationship between the operation time of engine 110 according to one embodiment of the present invention and the rotation speed of rotor blades 230. In FIG. 6, the horizontal axis represents the operation time of engine 110. In FIG. 6, the vertical axis represents the rotation speed of rotor blades 230.

[0046] As shown in Fig. 6, for example, assume that the rotation speed of the rotary vanes 230 is rotation speed Rini at time t1 when the filter 220 is in the first state (see Fig. 3). As described above, when the operation of the engine 110 continues from the first state, the region where particulate matter accumulates expands from the central region 220a of the filter 220 toward the outer periphery region 220b. Therefore, as time passes from the first state, the location where the exhaust gas hits the rotary vanes 230 moves from the center to the outer periphery (tip) of the rotary vanes 230. Therefore, as time passes from the first state, the rotation speed of the rotary vanes 230 gradually increases from the rotation speed Rini.

[0047] Then, at time t2 when the filter 220 enters the second state (see FIG. 4), the rotation speed of the rotary vanes 230 becomes the maximum rotation speed Rmax.

[0048] As more time passes from time t2, particulate matter accumulates in all areas of the filter 220, and the exhaust gas impinges on the entire rotating blades 230. Therefore, after time t2, the rotation speed of the rotating blades 230 gradually decreases from the rotation speed Rmax as time passes.

[0049] Returning to Fig. 2, in this embodiment, the accumulation amount estimation unit 262 refers to correlation information stored in the storage unit 270 described later, and executes an estimation process to estimate the accumulation amount of particulate matter in the filter 220 based on the rotation speed of the rotary vane 230. The correlation information is information indicating the correlation between the accumulation amount of particulate matter in the filter 220 and the rotation speed of the rotary vane 230. The correlation information is created by an experiment or a simulation, and is stored in the storage unit 270 in advance.

[0050] The engine control unit 264 controls the engine 110. In this embodiment, when the amount of particulate matter accumulated estimated by the accumulation amount estimation unit 262 becomes equal to or greater than a predetermined amount threshold Tha, the engine control unit 264 cuts fuel to the engine 110, sends air to the filter 220, and executes the regeneration process. The amount threshold Tha is determined to be the maximum amount of accumulation at which the particulate matter can be burned without abnormal combustion in the regeneration process. For example, the amount threshold Tha is determined to be the amount of accumulation of particulate matter when the rotation speed of the rotor blades 230 reaches the maximum rotation speed Rmax and then becomes the rotation speed Rtha in the process in which the rate of change of the rotation speed becomes negative (see FIG. 6). Information indicating the amount threshold Tha is stored in advance in the storage unit 270.

[0051] The motor control unit 266 connects the motor 240 to the rotor blades 230 and operates the motor 240 while the regeneration process is being performed.

[0052] The storage unit 270 stores the correlation information and information indicating the amount threshold Tha.

[0053] [How to play] Next, a method for regenerating the filter 220 using the exhaust gas purification device 200 will be described. Fig. 7 is a flowchart showing the flow of processes of the method for regenerating the filter 220 according to one embodiment of the present invention. As shown in Fig. 7, the regeneration method according to this embodiment includes a steady state determination process S110, an acquisition process S112, an estimation process S114, a decrease determination process S116, an accumulation amount determination process S118, and a regeneration process S120. Each process will be described below. In this embodiment, the regeneration method is repeatedly performed by an interruption that occurs at a predetermined time interval.

[0054] [Steady state determination process S110] The signal acquisition unit 260 judges whether the flow rate of the exhaust gas flowing through the exhaust passage 130 is in a steady state. As a result, if it is judged to be in a steady state (YES in S110), the signal acquisition unit 260 proceeds to acquisition processing S112. On the other hand, if it is judged not to be in a steady state (NO in S110), the signal acquisition unit 260 ends the regeneration method.

[0055] [Acquisition process S112] The signal acquisition unit 260 acquires the rotation speed R of the rotary blades 230 .

[0056] [Estimation process S114] The accumulation amount estimation unit 262 refers to the correlation information stored in the storage unit 270, and estimates the accumulation amount Eq of particulate matter in the filter 220 based on the rotation speed R acquired in the acquisition process S112.

[0057] [Decrease determination process S116] The engine control unit 264 compares the previous value, which is the rotation speed R acquired in the previous acquisition process S112, with the current value, which is the rotation speed R acquired in the current acquisition process S112. Then, the engine control unit 264 determines whether the rotation speed R acquired in the current acquisition process S112 has decreased from the previous value. As a result, when it is determined that the rotation speed R has decreased from the previous value (YES in S116), the engine control unit 264 shifts the process to the accumulation amount determination process S118. On the other hand, when it is determined that the rotation speed R has not decreased from the previous value (NO in S116), the engine control unit 264 ends the regeneration method.

[0058] [Deposition amount determination process S118] The engine control unit 264 judges whether the accumulation amount Eq estimated in the estimation process S114 is equal to or greater than the amount threshold value Tha stored in the storage unit 270. As a result, when it is judged that the accumulation amount Eq is equal to or greater than the amount threshold value Tha (YES in S118), the engine control unit 264 shifts the process to the regeneration process S120. On the other hand, when it is judged that the accumulation amount Eq is not equal to or greater than the amount threshold value Tha, that is, when it is judged that the accumulation amount Eq is less than the amount threshold value Tha (NO in S118), the engine control unit 264 ends the regeneration method.

[0059] [Regeneration process S120] The engine control unit 264 performs the regeneration process by cutting fuel to the engine 110 and sending air to the filter 220. In addition, the motor control unit 266 connects the motor 240 to the rotor blades 230 and causes the motor 240 to operate.

[0060] As described above, the exhaust gas purification device 200 according to this embodiment executes the estimation process based on the transition of the rotation speed of the rotary vanes 230. As described above, in the initial stage when particulate matter starts to accumulate on the filter 220, as shown in FIG. 3, there is no bias in the accumulation distribution of the particulate matter on the filter 220. After that, the particulate matter gradually accumulates from the central region 220a to the outer peripheral region 220b of the filter 220, and the accumulation distribution becomes biased. Therefore, the exhaust gas transitions from a first state (see FIG. 3) in which the exhaust gas mainly passes through the central region 220a of the filter 220 to a second state (see FIG. 4) in which the exhaust gas mainly passes through the outer peripheral region 220b, so that the rotation speed of the rotary vanes 230 gradually increases from the initial rotation speed Rini until it reaches the maximum rotation speed Rmax.

[0061] Then, in the middle stage where the accumulation of particulate matter has progressed to a certain extent, as shown in FIG. 4, the exhaust gas passes through the outermost peripheral region 220b, and the rotation speed of the rotary vanes 230 reaches the maximum rotation speed Rmax. After that, in the later stage where the accumulation of particulate matter has progressed further, as shown in FIG. 5, the particulate matter accumulates on the entire filter 220, and the accumulation distribution becomes even, and the exhaust gas passes through the entire filter 220, and the third state is reached. In this way, the exhaust gas transitions from the second state (see FIG. 4) where the exhaust gas mainly passes through the peripheral region 220b to the third state (see FIG. 5) where the exhaust gas passes through the entire region of the filter 220, and the rotation speed of the rotary vanes 230 gradually decreases from the maximum rotation speed Rmax, and finally reaches the rotation speed Rtha corresponding to the state where the regeneration process of the filter 220 is required. In this way, the rotation speed of the rotary vanes 230 changes based on the accumulation distribution and accumulation amount of particulate matter on the filter 220.

[0062] Therefore, the exhaust gas purification device 200 according to this embodiment estimates the amount of particulate matter deposited on the filter 220 based on the transition (change over time) of the rotation speed of the rotary vanes 230, and can estimate the amount of deposition with high accuracy compared to the conventional technology that estimates the amount of deposition based on the pressure difference between before and after the filter 220. This makes it possible for the exhaust gas purification device 200 to execute the regeneration process at an appropriate timing.

[0063] As described above, the exhaust gas purification device 200 executes the regeneration process when the rotation speed of the rotary vanes 230 increases to the rotation speed Rmax (first rotation speed) and then decreases to the rotation speed Rtha (second rotation speed) that is less than the rotation speed Rmax. This allows the exhaust gas purification device 200 to execute the regeneration process at a timing when the regeneration process of the filter 220 is required after particulate matter has accumulated over the entire area of ​​the filter 220. Therefore, the exhaust gas purification device 200 can avoid a situation in which the regeneration process is executed before the regeneration process of the filter 220 is required.

[0064] As described above, the signal acquiring unit 260 acquires the rotation speed of the rotating impeller 230 when the flow rate of the exhaust gas flowing through the exhaust passage 130 is in a steady state (for example, during warm-up of the engine 110). This makes it possible to eliminate fluctuations in the rotation speed of the rotating impeller 230 caused by differences in the flow rate of the exhaust gas, and to detect fluctuations in the rotation speed caused by the deposition distribution and deposition amount of particulate matter in the filter 220.

[0065] As described above, the exhaust gas purification device 200 includes the motor 240 and the motor control unit 266. The motor 240 and the motor control unit 266 rotate the rotary vanes 230 while the regeneration process is being performed. This allows the exhaust gas purification device 200 to increase the amount of fresh air (oxygen) supplied to the filter 220 while the regeneration process is being performed. Therefore, the exhaust gas purification device 200 can efficiently perform the regeneration process of the filter 220.

[0066] [First Modification] In the above embodiment, an example has been described in which the exhaust gas purification device 200 executes the process of estimating the accumulation amount based on the transition of the rotation speed of the rotary vanes 230, and executes the process of regenerating the filter 220 based on the estimated accumulation amount. However, the exhaust gas purification device 200 may execute the process of regenerating the filter 220 based on the transition of the rotation speed of the rotary vanes 230 without executing the process of estimating the accumulation amount.

[0067] FIG. 8 is a block diagram showing an example of a functional configuration of the control device 350 according to the first modified example. For example, as shown in FIG. 8, the control device 350 has a signal acquisition unit 260, an engine control unit 364, a motor control unit 266, and a storage unit 370. Note that various processes including the processes described below performed by the signal acquisition unit 260, the engine control unit 364, and the motor control unit 266 can be executed by the processor 252. In detail, various processes are executed by the processor 252 executing a program stored in the memory 254. Note that components substantially equivalent to those of the control device 250 of the above embodiment are denoted by the same reference numerals and will not be described.

[0068] In the first modified example, the engine control unit 364 executes the regeneration process based on the transition of the rotation speed of the rotary vanes 230. The specific process performed by the engine control unit 364 will be described in detail later.

[0069] In the first modified example, the storage unit 370 stores regeneration process execution information. The regeneration process execution information is information indicating the rotation speed Rtha of the rotary vane 230 when the amount threshold value Tha is reached. The regeneration process execution information is created by an experiment or a simulation, and is stored in the storage unit 370 in advance.

[0070] Next, a regeneration method for the filter 220 according to the first modified example will be described. FIG. 9 is a flowchart showing the flow of the process of the regeneration method for the filter 220 according to the first modified example. As shown in FIG. 9, the regeneration method according to the first modified example includes a steady state determination process S110, an acquisition process S112, a decrease determination process S116, a rotation speed determination process S318, and a regeneration process S120. Each process will be described below. In the first modified example, the regeneration method is repeatedly performed by an interrupt that occurs at a predetermined time interval. In addition, the same reference numerals are used for processes that are substantially the same as those in the regeneration method of the above embodiment, and the description thereof will be omitted.

[0071] [Rotation speed determination process S318] When it is determined that the current value of the rotation speed R has decreased from the previous value (YES in S116), the engine control unit 364 determines whether the rotation speed R acquired in the acquisition process S112 is equal to or less than the rotation speed Rtha. As a result, when it is determined that the rotation speed R is equal to or less than the rotation speed Rtha (YES in S318), the engine control unit 364 shifts the process to the regeneration process S120. On the other hand, when it is determined that the rotation speed R is not equal to or less than the rotation speed Rtha, that is, when it is determined that the rotation speed R is greater than the rotation speed Rtha (NO in S318), the engine control unit 364 ends the regeneration method.

[0072] As described above, in the first modified example, the exhaust gas purification device 200 executes the regeneration process based on the transition of the rotation speed of the rotating vanes 230. As described above, the rotation speed of the rotating vanes 230 changes based on the accumulation distribution and the accumulation amount of particulate matter in the filter 220.

[0073] Therefore, in the first modified example, the exhaust gas purification device 200 performs the regeneration process based on the change in the rotational speed of the rotating vanes 230 (change over time), thereby making it possible to perform the regeneration process at an appropriate timing, compared to the conventional technology in which the regeneration process is performed based on the differential pressure before and after the filter 220.

[0074] Moreover, in the first modified example, the control device 350 differs from the control device 250 of the above embodiment in that it does not estimate the amount of particulate matter accumulated in the filter 220. Therefore, in the first modified example, the control device 350 can reduce the processing load.

[0075] [Second modified example] In the above embodiment, an example has been described in which the exhaust gas purification device 200 executes the process of estimating the accumulation amount based on the change in the rotation speed of the rotary vanes 230. However, the exhaust gas purification device 200 may execute the process of estimating the accumulation amount based on the rotation speed of the rotary vanes 230 itself.

[0076] Fig. 10 is a flowchart showing the flow of the process of the regeneration method of the filter 220 according to the second modified example. As shown in Fig. 10, the regeneration method according to the second modified example includes a steady state determination process S110, an acquisition process S112, an estimation process S114, a rotation speed determination process S410, a flag ON process S412, a flag determination process S414, an accumulation amount determination process S118, a regeneration process S120, and a flag OFF process S416. Each process will be described below. In addition, in the second modified example, the regeneration method is repeatedly performed by an interruption that occurs at a predetermined time interval. In addition, the processes substantially the same as those in the regeneration method of the above embodiment are denoted by the same reference numerals and will not be described.

[0077] [Rotation speed determination process S410] The engine control unit 264 determines whether the rotation speed R acquired in the acquisition process S112 is the rotation speed Rmax (first rotation speed). As a result, when it is determined that the rotation speed R is the rotation speed Rmax (YES in S410), the engine control unit 264 shifts the process to a flag ON process S412. On the other hand, when it is determined that the rotation speed R is not the rotation speed Rmax, that is, is less than the rotation speed Rmax (NO in S410), the engine control unit 264 shifts the process to a flag determination process S414.

[0078] [Flag ON processing S412] The engine control unit 264 turns ON a flag indicating that the rotation speed R of the rotary vanes 230 has reached the rotation speed Rmax. When the rotation speed R of the rotary vanes 230 is less than the rotation speed Rmax, the flag is turned OFF.

[0079] [Flag determination process S414] The engine control unit 264 judges whether the flag is ON or not. As a result, when it is judged that the flag is ON (YES in S414), the engine control unit 264 shifts the process to the accumulation amount judgment process S118. On the other hand, when the flag is not ON, that is, when the flag is OFF (NO in S414), the engine control unit 264 ends the regeneration method.

[0080] [Flag OFF process S416] When the reproduction process S120 is executed, the engine control unit 264 turns the flag OFF.

[0081] As described above, in the second modified example, the exhaust gas purification device 200 executes the estimation process based on the rotation speed itself of the rotary vanes 230. As described above, the rotation speed of the rotary vanes 230 changes based on the accumulation distribution and accumulation amount of particulate matter on the filter 220.

[0082] Therefore, in the second variant, the exhaust gas purification device 200 estimates the amount of particulate matter in the filter 220 based on the rotational speed of the rotating vanes 230, and can estimate the amount of deposition with high accuracy compared to the conventional technology that estimates the amount of deposition based on the differential pressure before and after the filter 220.

[0083] [Third modified example] In the above second modified example, an example has been described in which the exhaust gas purification device 200 executes the process of estimating the accumulation amount based on the rotation speed of the rotary vanes 230 itself, and executes the process of regenerating the filter 220 based on the estimated accumulation amount. However, the exhaust gas purification device 200 may execute the process of regenerating the filter 220 based on the rotation speed of the rotary vanes 230 itself, without executing the process of estimating the accumulation amount.

[0084] FIG. 11 is a flowchart showing the flow of the process of the regeneration method of the filter 220 according to the third modified example. As shown in FIG. 11, the regeneration method according to the third modified example includes a steady state determination process S110, an acquisition process S112, a rotation speed determination process S410, a flag ON process S412, a flag determination process S414, a rotation speed determination process S318, a regeneration process S120, and a flag OFF process S416. In the third modified example, the regeneration method is repeatedly performed by an interruption that occurs at a predetermined time interval. In addition, the processes substantially equivalent to those in the regeneration methods of the above embodiment, the first modified example, and the second modified example are denoted by the same reference numerals and will not be described.

[0085] In the third modified example, the exhaust gas purification device 200 performs the regeneration process based on the rotation speed itself of the rotary vanes 230. As described above, the rotation speed of the rotary vanes 230 varies based on the accumulation distribution and amount of particulate matter on the filter 220.

[0086] Therefore, in the third modified example, the exhaust gas purification device 200 performs the regeneration process based on the rotation speed of the rotating vanes 230, and thereby becomes able to perform the regeneration process at an appropriate timing, compared to the conventional technology in which the regeneration process is performed based on the differential pressure before and after the filter 220.

[0087] Moreover, in the third modified example, the control device 350 differs from the control device 250 in the second modified example in that it does not estimate the amount of particulate matter accumulated in the filter 220. Therefore, in the third modified example, the control device 350 can reduce the processing load.

[0088] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can think of various modifications or alterations within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0089] For example, in the above embodiment and the first to third modified examples, the exhaust gas purification device 200 has been described as performing the estimation process or the regeneration process based on the rotation speed of the rotary vanes 230 when the flow rate of the exhaust gas flowing through the exhaust passage 130 is in a steady state. However, the exhaust gas purification device 200 may perform the estimation process or the regeneration process based on a correction value obtained by correcting the rotation speed of the rotary vanes 230 with the flow rate of the exhaust gas flowing through the exhaust passage 130. By performing the estimation process or the regeneration process based on the correction value, the exhaust gas purification device 200 can eliminate the fluctuation in the rotation speed of the rotary vanes 230 caused by the difference in the flow rate of the exhaust gas, and can perform the estimation process or the regeneration process based on the rotation speed caused by the deposition distribution and deposition amount of particulate matter in the filter 220. Therefore, the exhaust gas purification device 200 can improve the estimation accuracy of the deposition amount and the determination accuracy of the timing to perform the regeneration process.

[0090] In the above embodiment and the second to third modified examples, the rotation speed Rmax, which is the maximum rotation speed of the rotary vane 230, is taken as an example of the first rotation speed. However, the first rotation speed may be a value less than the rotation speed Rmax or more than the rotation speed Rtha. In this case, the exhaust gas purification device 200 may execute the regeneration process or the estimation process when the rotation speed of the rotary vane 230 increases to the first rotation speed or more and then decreases to a second rotation speed or less that is less than the first rotation speed. In the above embodiment and the first to third modified examples, the rotation speed Rtha corresponding to a state in which the regeneration process of the filter 220 is required is taken as an example of the second rotation speed. However, the second rotation speed may be a value less than the first rotation speed or more than the rotation speed Rtha.

[0091] In the above embodiment and the second modified example, the exhaust gas purification device 200 has been described as performing the estimation process at all times. However, the exhaust gas purification device 200 may perform the estimation process when the rotation speed of the rotary vanes 230 increases to a first rotation speed or more and then decreases to a second rotation speed or less that is less than the first rotation speed. This allows the exhaust gas purification device 200 to perform the estimation process only for a predetermined period before and after the start of the regeneration process. This allows the control devices 250 and 350 to reduce the calculation load required for the estimation process.

[0092] In the above embodiment and the first to third modified examples, the filter 220 is used as a GPF. However, the filter 220 may be used as a DPF (Diesel Particulate Filter). In other words, the engine 110 may be a diesel engine. [Explanation of symbols]

[0093] 200 Exhaust gas purification device 220 Filters 230 Rotor 250 Control device 350 Control device

Claims

1. A filter provided in an exhaust passage connected to the engine; a rotary vane provided downstream of the filter in the exhaust passage; A control device having one or more processors and one or more memories coupled to the processors; Equipped with The processor, An exhaust gas purification device that performs a process including at least one of an estimation process that estimates the amount of particulate matter deposited on the filter based on the rotational speed of the rotating blades, which rotate passively due to the flow of exhaust gas through the exhaust passage, and a regeneration process that regenerates the filter.

2. The processor, The exhaust gas purification device according to claim 1 , wherein the estimation process or the regeneration process is performed based on a change in the rotation speed of the rotary vanes.

3. The processor, 3. The exhaust gas purification device according to claim 2, wherein the estimation process or the regeneration process is executed when, as the operating time of the engine elapses, the rotational speed of the rotor blades increases to or exceeds a first rotational speed and then decreases to or below a second rotational speed that is lower than the first rotational speed.

4. The processor, 3. The exhaust gas purification device according to claim 1, wherein the estimation process or the regeneration process is performed based on a rotation speed of the rotary vanes when a flow rate of the exhaust gas flowing through the exhaust passage is in a steady state.

5. The processor, 3. The exhaust gas purification device according to claim 1, wherein the estimation process or the regeneration process is performed based on a correction value obtained by correcting the rotation speed of the rotary vanes with a flow rate of exhaust gas flowing through the exhaust passage.

Images