JP5739605B2 - Engine exhaust purification system - Google Patents

Description

  The present invention relates to an engine exhaust gas purification system technology.

  2. Description of the Related Art Conventionally, an exhaust emission control device having a particulate filter is known as a technique for collecting particulates contained in exhaust gas discharged from an engine. The particulate filter has a porous honeycomb structure made of ceramic or the like, and the inlets of the flow paths partitioned in a lattice pattern are alternately sealed. And about the flow path in which the inlet_port | entrance is not sealed, it is comprised so that the exit may be sealed, and only the exhaust gas which permeate | transmitted the porous wall which divides each flow path is discharged | emitted downstream. When the exhaust gas permeates through the porous chamber wall, the exhaust gas is purified by trapping the particulates in the exhaust gas inside the porous chamber wall.

  However, since the particulate matter collected inside the porous chamber wall gradually accumulates, the accumulation causes an increase in exhaust resistance, a differential pressure between the inlet side and the outlet side of the particulate filter, etc. The engine performance could be affected. Therefore, it is necessary to regenerate the particulate filter by appropriately burning and removing the particulate deposited on the particulate filter.

  Therefore, by controlling the fuel injection valve provided in the engine, so-called post-injection (fuel injection performed after the main injection, the particulate filter removes unburned hydrocarbons (HC) together with the exhaust gas without burning in the cylinder) A technique for performing fuel injection aiming to be supplied to the fuel is known. For example, it is like patent document 1. In this technique, unburned hydrocarbon (HC) is reacted with an oxidation catalyst supported on a particulate filter, and particulates deposited on the particulate filter are burned and removed using the reaction heat.

  However, since the technique described in Patent Document 1 forcibly raises the temperature of exhaust gas in the exhaust purification device by post-injection of the fuel injection valve, there is a possibility that the operating state of the engine may change suddenly. Therefore, when regenerating the particulate filter, it is necessary to stop the operation of the engine-equipped equipment such as a vehicle provided with the exhaust purification device.

JP 2003-83139 A

  The present invention has been made in view of the above-described problems, and the problem to be solved is to regenerate the particulate filter without interrupting work or running using the engine-equipped device. The present invention provides an exhaust purification system for an engine.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

According to a first aspect of the present invention, a particulate filter that is arranged in the middle of the exhaust path of the engine and collects particulates, and an intake air that is arranged in the intake path of the engine and drives and controls the intake throttle actuator to change the opening degree. An amount adjusting means, an exhaust amount adjusting means disposed in the exhaust path of the engine and drivingly controlling an exhaust throttle actuator to change the opening; and the intake amount adjusting means and / or the exhaust amount adjusting means. Thus, an engine having a regeneration means for burning and removing the particulate matter collected by the particulate filter, an engine load detection sensor, an engine speed detection sensor, and an engine exhaust temperature detection means. In an exhaust purification system, the engine speed detection and the engine speed detected by the engine speed detection sensor. Based on the detection result of the load factor detected by the sensor, it is determined whether the engine operating state is a steady state or a transient state, and the transient filter or the steady state filter is selected as an applied filter based on the determination result An engine operating state determining means, and when the exhaust temperature is higher than a predetermined temperature according to the exhaust temperature detected by the exhaust temperature detecting means, the control operation of the exhaust amount adjusting means is started, At the same time, or after the set time elapses or after the exhaust gas temperature reaches the set temperature, the control operation of the intake air amount adjusting unit is started. When the exhaust gas temperature is lower than the predetermined temperature, the control of the exhaust air amount adjusting unit is started. After the set time elapses or the exhaust gas temperature reaches the set temperature, the control operation of the intake air amount adjusting means is started, and the engine speed and A storage unit storing a relationship map for determining a relationship between a load factor and an operation of the intake air amount adjusting unit and / or the exhaust gas amount adjusting unit, and the intake air amount adjusting unit and / or Alternatively, the target operation of the exhaust amount adjusting means is set and the signal is allowed to pass by using the transient filter or the steady-state filter as an applied filter according to the determination result of the engine operating state determination means. And the intake air amount adjusting means and / or the exhaust air amount adjusting means controls the drive speeds of the intake throttle actuator and the exhaust throttle actuator, and performs the target operation at the set change speed. It controls to make.

According to a second aspect of the present invention, in the engine exhaust gas purification system according to the first aspect, the storage means includes a fuel injection of a fuel injection valve, an injection timing, an injection frequency, an injection pressure, an engine speed and a load factor. And a relationship map for fuel injection is set. At least one of a target injection timing, a target number of injections, and a target injection pressure of the fuel injection valve is set from the relationship map for fuel injection, and the engine operating state determination means The target injection timing, the target number of injections, and the change speed to the target injection pressure are set by passing a signal using the transient filter or the stationary filter as an applied filter according to the determination result, and the fuel injection At least one of the target injection timing, the target number of injections, and the target injection pressure at the set change speed for the drive speed of the fuel injection actuator of the valve One in and is to control.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, it is possible to appropriately regenerate the particulate filter without performing post-injection of the fuel injection valve in the engine, and it is not necessary to stop the operation of the work vehicle that is the engine-equipped device. Therefore, when the particulate filter is regenerated, the work using the work vehicle can be continued.

Further, since the change rate of the intake air amount adjusting means and / or the exhaust air amount adjusting means can be set appropriately, the color change of exhaust gas, the generation of odor, the generation of noise, etc. accompanying the regeneration of the particulate filter, etc. Can be reduced, and the deterioration of the operating environment of the operator can be prevented.

According to the second aspect of the present invention, the change timing when changing the injection timing, the number of injections, and the injection timing of the fuel injection valve can be appropriately set. Therefore, the color change and odor of the exhaust gas accompanying the regeneration of the particulate filter Occurrence of noise or noise can be reduced, and deterioration of the operating environment of the operator can be prevented.

1 is a schematic diagram showing the configuration of an engine exhaust purification system according to the present invention. The flowchart figure which shows reproduction | regeneration control of a particulate filter. FIG. 3 is a flowchart showing particulate filter regeneration control when the exhaust gas temperature in the exhaust gas purification apparatus is higher than a predetermined temperature in FIG. 2. FIG. 3 is a flowchart showing particulate filter regeneration control when the exhaust gas temperature in the exhaust gas purification apparatus is lower than a predetermined temperature in FIG. 2. The flowchart figure which shows the setting procedure of the target opening degree of an intake throttle valve and an exhaust throttle valve. The flowchart figure which shows the setting procedure of the target injection timing and target injection pressure of a fuel injection valve. The flowchart figure which shows the setting procedure of an application filter. The block diagram which shows a control structure.

  Hereinafter, an embodiment of an engine exhaust purification system according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the exhaust purification system 1 purifies exhaust discharged from the engine 2. An exhaust purification system 1 is provided in an engine 2 and includes an exhaust purification device having a particulate filter 10 and an oxidation catalyst 11, an intake throttle valve 12, an exhaust throttle valve 13, a deposition amount detection sensor 33, a temperature sensor 21, and an engine speed detection. A sensor 22, an engine load detection sensor 23, an ECU 30 as engine control means, and the like are provided.

  The engine 2 includes one or a plurality of cylinders, and converts energy generated by burning fuel injected into the cylinders into rotational power. The engine 2 mixes and burns outside air supplied through the intake passage 3 and fuel supplied from the fuel injection valves 4, 4, 4, 4 in the cylinders 5, 5, 5, 5. Exhaust gas generated at this time is discharged through the exhaust path 6. Although the engine 2 according to this embodiment is an in-line four cylinder, it is not limited to this.

  The fuel injection valve 4 changes the injection timing, the injection pressure, the number of injections, etc. when the high pressure fuel from the common rail is injected into the cylinder 5 by opening and closing the valve body by the solenoid as the fuel injection actuator 7. Thus, it is possible to change the rotational speed and load of the engine 2, change the temperature of the exhaust gas, and supply unburned fuel to the exhaust gas. However, it can also be realized by a rack type electronic governor or the like.

  The particulate filter 10 is disposed in the exhaust path 6 of the engine 2 and removes particulates (e.g., carbonaceous soot, high boiling point hydrocarbon component (SOF)) in the exhaust. Specifically, the particulate filter 10 has a honeycomb structure composed of a porous wall made of ceramic or the like, and the exhaust is necessarily discharged after passing through the porous wall. The particulate filter 10 collects particulates in the exhaust when the exhaust passes through the porous wall. As a result, particulates are removed from the exhaust.

  The oxidation catalyst 11 oxidizes carbon monoxide, hydrocarbons and nitrogen compounds in the exhaust gas. The oxidation catalyst 11 is disposed on the upstream side of the particulate filter 10 in the exhaust passage 6 and promotes the oxidation removal of the particulates.

  The intake throttle valve 12 is disposed in the intake path 3 of the engine 2 and is configured to be able to change the opening degree by driving an intake throttle actuator 15. The intake throttle valve 12 can adjust the flow rate of the intake air flowing through the intake path 3 of the engine 2 by changing the opening, and as a result, the temperature and speed of the exhaust gas can be changed. An intake throttle sensor 14 is connected to the intake throttle valve 12. The intake throttle sensor 14 detects the opening of the intake throttle valve 12. The intake throttle valve 12 is an example of an intake air amount adjusting means, and is not limited to this, and any device that can adjust the flow amount of intake air flowing through the intake passage 3 may be used. The opening of the intake throttle valve 12 refers to the operation of the intake air amount adjusting means, and in this embodiment refers to the degree of opening / closing of the intake path 3.

  The exhaust throttle valve 13 is disposed upstream of the oxidation catalyst 11 in the exhaust path 6 of the engine 2 and is configured to be able to change the opening degree by driving an exhaust throttle actuator 25. The exhaust throttle valve 13 can adjust the flow rate of exhaust gas (exhaust gas) flowing through the exhaust path 6 of the engine 2 by changing the opening, and can change the pressure and speed of the exhaust gas. An exhaust throttle sensor 24 is connected to the exhaust throttle valve 13. The exhaust throttle sensor 24 detects the opening degree of the exhaust throttle valve 13. The exhaust throttle valve 13 is an example of an exhaust amount adjusting means, and is not limited to this, and any device that can adjust the amount of exhaust gas flowing in the exhaust path 6 may be used. Further, the opening degree of the exhaust throttle valve 13 refers to the operation of the exhaust amount adjusting means, and in this embodiment refers to the degree of opening and closing of the exhaust path 6.

  The accumulation amount detection sensor 33 detects the particulate matter collected by the particulate filter 10 from the pressure difference between the inlet side and the outlet side of the particulate filter 10 and the flow amount of exhaust gas passing through the particulate filter 10. The amount of deposition is detected.

  The temperature sensor 21 is disposed on the outlet side (downstream side) of the particulate filter 10 and detects the temperature of the exhaust gas that has passed through the particulate filter 10. The temperature sensor 21 is an example of the exhaust gas temperature detecting means, and is not limited to this, and any device that can detect the temperature of the exhaust gas may be used.

  The engine rotation speed detection sensor 22 detects the rotation speed of a crankshaft (not shown) of the engine 2.

  The engine load detection sensor 23 detects a shaft torque of a crankshaft (not shown) of the engine 2. However, the engine load can be obtained from the set rotational speed and the actual rotational speed, or from the actual fuel injection amount with respect to the set fuel injection amount.

  Next, the ECU 30 will be described.

  The ECU 30 is an example of a control unit, and includes an arithmetic unit such as a central processing unit (CPU) that executes arithmetic processing, a storage unit 70 (RAM or ROM), an interface, and the like, and inputs signals from various sensors and the like. It is possible. A control program to be output to the fuel injection actuator 7 is stored in the ROM.

  In the storage unit 70, a relationship map (an intake throttle valve map and an exhaust throttle valve map) between the opening degrees of the intake throttle valve 12 and the exhaust throttle valve 13 and the engine state derived from the rotational speed and load factor of the engine 2 is stored. It is remembered. The openings of the intake throttle valve 12 and the exhaust throttle valve 13 are respectively referred to the intake throttle valve map and the exhaust throttle valve map, which are the relationship maps, from the engine state derived from the rotational speed and load factor of the engine 2. It is comprised so that it may be calculated by the said calculating part.

  As shown in FIG. 8, the ECU 30 includes a fuel injection actuator 7, an engine speed detection sensor 22, an engine load detection sensor 23, an intake throttle sensor 14, an intake throttle actuator 15, an exhaust throttle sensor 24, and an exhaust throttle actuator 25. The accumulation amount detection sensor 33, the temperature sensor 21 and the like are connected.

  The ECU 30 determines whether the operating state of the engine 2 is a steady state or a transient state based on detection results detected by the engine speed detection sensor 22 and the engine load detection sensor 23 of the engine 2. It is. That is, the ECU 30 has an operation state determination unit for the engine 2 in one embodiment of the present invention. The operation state determination means of the engine 2 is not limited to this, and any means that can determine whether the operation state of the engine 2 is a steady state or a transient state may be used.

  Further, the ECU 30 regenerates the particulate filter 10, that is, includes a regeneration means for burning and removing the particulate matter collected and deposited by the particulate filter 10, and controls the exhaust purification system of the engine 2. It has a function. The regeneration means of the particulate filter 10 is not limited to this, and any means may be used as long as it can burn and remove the particulates collected and deposited on the particulate filter 10.

  The ECU 30 is configured so that the actuators 7, 15, and 25 can be driven and controlled when the particulate filter 10 is regenerated.

  Specifically, the ECU 30 is configured to be able to change the injection timing, the number of injections, and the injection pressure of the fuel injection valve 4 by drivingly controlling the fuel injection actuator 7. In the case of an electronic governor, the speed at which the rack is moved can be changed.

  Further, the ECU 30 can drive and control the intake throttle actuator 15 to change the opening degree of the intake throttle valve 12, and configures the change speed of the opening degree, that is, the valve body of the intake throttle valve 12. The rotation speed of the butterfly valve can be freely changed.

  Further, the ECU 30 can drive and control the exhaust throttle actuator 25 to change the opening degree of the exhaust throttle valve 13, and configures the valve opening speed of the exhaust throttle valve 13, that is, the exhaust throttle valve 13. The rotation speed of the butterfly valve can be freely changed.

  The exhaust purification system 1 for an engine 2 according to an embodiment of the present invention raises the temperature of the exhaust gas from about 600 ° C. to about 400 ° C., which is lower than the conventional temperature. The regeneration of the particulate filter 10 can be executed. At the time of regeneration, post-injection by the fuel injection valve 4 is not performed, the opening of the intake throttle valve 12 and the exhaust throttle valve 13 is changed, and the injection timing of the fuel injection valve 4 is performed in addition to the change of the opening, The exhaust gas discharged from the engine 2 is heated to about 400 ° C. by changing the number of injections and the injection pressure.

  Thus, it is not necessary to perform post injection of the fuel injection valve 4 in order to regenerate the particulate filter 10. Therefore, the particulate filter 10 can be regenerated even when the engine-equipped equipment including the exhaust purification system 1 for the engine 2 according to the embodiment of the present invention, in this embodiment, the work vehicle is running. There is no need to temporarily stop to do so. That is, even while the particulate filter 10 is being regenerated, it is possible to perform work using this by running the work vehicle. The engine-equipped device is not limited to this, and may be an engine generator or a ship.

  Hereinafter, the regeneration control of the particulate filter 10 that exhibits such an effect will be described with reference to a flowchart. In addition, about the step which performs the same process, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  First, as shown in FIG. 2, the exhaust gas temperature Tdpf on the outlet side (downstream side) of the particulate filter 10 is detected by the exhaust gas temperature detection sensor 21 (S10), and the exhaust gas temperature Tdpf is the first set temperature. The ECU 30 determines whether or not the temperature is higher than that (S11).

  Hereinafter, the case where the exhaust gas temperature Tdpf is higher than the first set temperature will be described with reference to FIG.

  The target opening degree of the exhaust throttle valve 13 is set by the ECU 30 in accordance with the exhaust gas temperature Tdpf (S12), and the valve body used when the exhaust throttle valve 13 is changed to the target opening degree by performing processing by an application filter described later. The change speed is set (S13). Then, the opening degree is instructed by the ECU 30 according to the setting (S14), and the exhaust throttle valve 13 starts changing the opening degree according to the setting by the drive control of the exhaust throttle actuator 25 by the ECU 30.

  Similarly to the opening of the exhaust throttle valve 13, the ECU 30 sets at least one of the target injection timing, the target injection count, and the target injection pressure for the injection timing, the injection count, and the injection pressure of the fuel injection valve 4. It is a structure and the process by the application filter (The injection timing filter, the injection frequency filter, the injection pressure filter) mentioned later is performed, and the change speed to the set target injection timing, the target injection frequency, and the target injection pressure is set. It can be set as a structure. In response to this setting, the ECU 30 issues an instruction to change the fuel injection, and the fuel injection valve 4 is driven to the target injection timing, the target number of injections, and the target injection pressure according to the setting by the drive control of the fuel injection actuator 7 by the ECU 30. Change the current injection timing, number of injections, and injection pressure.

  In this configuration, first, the ECU 30 determines whether or not the intake throttle valve timer flag = 0 (S15). Note that the intake throttle valve timer flag means that the opening change from the setting of the target opening of the intake throttle valve 12 to the target opening, that is, steps 16 to 18 are executed after a predetermined time has elapsed. Flag.

  When the intake throttle valve timer flag = 0, that is, when the flag for operating the intake throttle valve 12 after a predetermined time has not been set (the signal is OFF), the ECU 30 causes the intake throttle valve 12 to open the target. The degree is set (S16), and the change speed of the valve body when the intake throttle valve 12 is changed to the target opening degree is set by performing processing by an application filter described later (S17). The opening degree is instructed by the ECU 30 according to the setting (S18), and the intake throttle valve 12 starts changing the opening degree according to the setting by the drive control of the intake throttle actuator 15 by the ECU 30. In this case, the exhaust throttle valve 13 and the intake throttle valve 12 simultaneously start changing their opening degrees.

  On the other hand, when the intake throttle valve timer flag is not 0 (intake throttle valve timer flag = 1), that is, when the flag for operating the intake throttle valve 12 after a predetermined time is set (the signal is ON), When the ECU 30 starts counting the intake throttle valve timer and a predetermined time has elapsed (S19), the intake throttle valve timer flag = 0 (S20), and the ECU 30 sets the target opening of the intake throttle valve 12 (S16).

  Even if the ECU 30 does not count the intake throttle valve timer, if the exhaust gas temperature Tdpf on the outlet side of the particulate filter 10 reaches the second set temperature (S21), the ECU 30 causes the target opening of the intake throttle valve 12 to be increased. Is set (S16).

  Hereinafter, the setting of the target opening will be described with reference to FIG.

  The engine speed detection sensor 22 of the engine 2 detects the speed of the engine 2 at regular intervals (S60). Then, the detected detection result is filtered (S61). The engine load detection sensor 23 of the engine 2 detects the load of the engine 2 at regular intervals, that is, the load factor (S62). Then, the detected detection result is filtered (S63).

  Then, the engine state is determined by the ECU 30 based on the rotation speed and the value that has passed through the filter of the load factor (S64).

  Then, according to the determined engine state, the intake throttle valve 12 refers to the intake throttle valve map which is the relation map (S65), and the target opening degree of the intake throttle valve 12 is set (S65). S66). On the other hand, in the exhaust throttle valve 13, a target opening degree of the exhaust throttle valve 13 is set (S68) with reference to the exhaust throttle valve map which is the relation map (S67).

  The filter is a filter that allows a signal within a predetermined range, a predetermined value, or a predetermined value to pass, and the values detected by the sensors 22 and 23 are within a desired range or within a desired value. Can determine if it is in.

  Further, as described above, also in the fuel injection valve 4, the target injection timing of the fuel injection valve 4 is set in the same procedure as the setting of the target opening of the intake throttle valve 12 and the exhaust throttle valve 13 as shown in FIG. In addition, at least one of the target number of injections and the target injection pressure can be set. Hereinafter, setting of the target injection timing, the target number of injections, and the target injection pressure of the fuel injection valve 4 will be described.

  In the storage unit 70 of the ECU 30, a relationship map (injection timing map, injection number map) between the injection timing of the fuel injection valve 4, the number of injections, the injection pressure, and the engine state derived from the rotation speed and load factor of the engine 2 is stored. , Injection pressure map) is stored. The injection timing, the number of injections, and the injection pressure of the fuel injection valve 4 are respectively calculated from the engine state derived from the rotational speed and load factor of the engine 2, and the injection timing map, the injection number map, and the injection pressure map, which are the relationship maps, respectively. It is configured to be calculated by the calculation unit with reference to.

  Specifically, as shown in FIG. 6, after the engine state is determined by the ECU 30 based on the value that has passed through the filter of the rotation speed and the load factor (S64), the fuel is determined according to the determined engine state. In the injection timing of the injection valve 4, the target injection timing of the fuel injection valve 4 is set (S70) with reference to the injection timing map which is the relationship map (S69). Further, regarding the number of injections of the fuel injection valve 4, the target number of injections of the fuel injection valve 4 is set (S72) by referring to the injection number map which is the relation map (S71). Further, with respect to the injection pressure of the fuel injection valve 4, the target injection pressure of the fuel injection valve 4 is set (S74) with reference to the injection pressure map which is the relation map (S73).

  Hereinafter, the applied filter will be described with reference to FIG.

  The applied filter passes the detected rotational speed and load value of the engine 2 and removes a predetermined value (or less) from the detected value. The ECU 30 determines whether the operating state of the engine 2 is a steady state or a transient state from the value after the removal, and the exhaust throttle valve 13 and the intake throttle valve 12 change the opening degree from the determination result. This is to set the change speed when doing. Further, the ECU 30 can be configured to set a change speed when changing the injection timing, the number of injections, and the injection pressure of the fuel injection valve 4 from the determination result of the steady state or the transient state. .

  As shown in FIG. 7, the operating state of the engine 2, which is in a steady state or a transient state, is set by the operating state determination means (ECU 30) when the engine 2 is in an acceleration state (set to 1). (S50) and the load input flag (S51) that is set at the time of load input (becomes 1) can also be determined. In this embodiment, the acceleration flag is set when the engine speed is equal to or higher than the set acceleration (the signal is turned ON), and the load input flag is set when the load is equal to or higher than the set load. (The signal turns ON).

  Then, the ECU 30 that is the operation state detection means of the engine 2 determines whether or not the operation state of the engine 2 is in a transient state based on the detection results of the acceleration flag and the load application flag (S52).

  When it is determined that the operating state of the engine 2 is in the transient state, the detection signal is allowed to pass through the transient filter (S53), and the applied filter for the transient state is applied (S55). Further, when it is determined that the operation state of the engine 2 is not a transient state (a steady state), the detection signal is passed through the steady state filter (S54), and the steady state applied filter is applied. (S55).

  Next, the case where the exhaust gas temperature Tdpf is equal to or lower than the first set temperature will be described with reference to FIG.

  In this case, first, the target opening degree of the exhaust throttle valve 13 is set by the ECU 30 (S30), and the change speed of the valve body when the exhaust throttle valve 13 is changed to the target opening degree by performing the processing by the application filter is set. (S31). Then, the opening degree is instructed by the ECU 30 according to the setting (S32), and the exhaust throttle valve 13 starts changing the opening degree according to the setting by the drive control of the exhaust throttle actuator 25 by the ECU 30.

  Similarly to the opening of the exhaust throttle valve 13, the ECU 30 sets at least one of the target injection timing, the target injection count, and the target injection pressure with respect to the injection timing, the number of injections, and the injection pressure of the fuel injection valve 4. In this configuration, processing is performed by the injection timing filter, the injection frequency filter, and the injection pressure filter, which are the application filters, and the set target injection timing, the target injection frequency, and the change speed to the target injection pressure are set. It can be. In response to this setting, the ECU 30 issues an instruction to change the fuel injection, and the fuel injection valve 4 is driven to the target injection timing, the target number of injections, and the target injection pressure according to the setting by the drive control of the fuel injection actuator 7 by the ECU 30. Change the current injection timing, number of injections, and injection pressure. In the above case, since the exhaust gas temperature is low, the engine itself is in a cold state and has not reached the temperature at which the oxidation catalyst 11 is activated. Therefore, the exhaust throttle valve 13 is fully opened and the fuel injection valve 4 is completely burned. It is set as follows.

  Next, the ECU 30 determines whether or not the intake throttle valve flag = 1 (S33).

  First, as will be described later, the intake throttle valve flag is set (set to 1) after a predetermined time has elapsed after the engine is started. At the time of engine start or low temperature, the intake throttle valve flag is not 1 but 0 (intake throttle valve flag = 0). In this case, the ECU 30 first determines whether or not the intake throttle valve timer flag = 1. (S34).

  If the intake throttle valve timer flag is not 1, the ECU 30 resets the count value of the intake throttle valve timer (S41), sets the intake throttle valve timer flag to 1 (S42), and starts counting the intake throttle valve timer (S43). ). If the count of the intake throttle valve timer has passed a predetermined time (S35), the intake throttle valve timer flag is set to 0 (S36), and the intake throttle valve flag is set to 1 (S37).

  In step 34, if the intake throttle valve timer flag is 1, if the exhaust gas temperature Tdpf on the outlet side of the particulate filter 10 reaches the second set temperature (S44), the intake throttle valve flag is set to 1. (S37).

  When the intake throttle valve flag becomes 1 (S37), the target opening of the intake throttle valve 12 is set by the ECU 30 (S38), and the processing by the application filter is performed to change the intake throttle valve 12 to the target opening. The change speed of the valve body is set (S39). The opening degree is instructed by the ECU 30 according to the setting (S40), and the intake throttle valve 12 starts changing the opening degree according to the setting by the drive control of the intake throttle actuator 15 by the ECU 30.

  In step 33, even when the intake throttle valve flag is 1, the ECU 30 sets the target opening degree of the intake throttle valve 12 (S38), and performs the processing by the applicable filter in the same manner as described above (S39). An instruction is given (S40). The intake throttle valve 12 starts changing the opening degree according to the setting by the drive control of the intake throttle actuator 15 by the ECU 30.

  With the above control configuration, regeneration control of the particulate filter 10 is started.

  Then, the intake throttle valve 12 and the exhaust throttle valve 13 during the regeneration of the particulate filter 10 are subjected to processing by the applied filter to set the valve element change speed. Further, the injection timing, the number of injections, and the injection pressure of the fuel injection valve 4 may be configured to be subjected to processing by the application filter (injection timing filter, injection number filter, injection pressure filter) and the change speed is set. it can.

  Further, the regeneration process of the particulate filter 10 is detected after a predetermined time has elapsed after at least one of the intake throttle valve 12 and the exhaust throttle valve 13 starts changing the opening degree or by the accumulation amount detection sensor 33. Execution is terminated after the accumulated amount of the particulate matter collected by the particulate filter 10 has decreased below a predetermined amount.

  At the end of execution of the regeneration process, the openings of the intake throttle valve 12 and the exhaust throttle valve 13 are fully opened. In this case, the intake throttle valve 12 and the exhaust throttle valve 13 are set with the valve element changing speed when the opening degree is fully opened by performing the process using the applied filter. Further, the injection timing, the number of injections, and the injection pressure of the fuel injection valve 4 may be configured to be subjected to processing by the application filter (injection timing filter, injection number filter, injection pressure filter) and the change speed is set. it can.

  As described above, the exhaust gas purification system for the engine 2 according to the embodiment of the present invention is arranged in the exhaust path 6 of the engine 2 and collects the particulate filter 10 for collecting particulates, and the intake path of the engine 2. 3 controls an intake throttle valve (intake amount adjusting means) 12 arranged at 3, an exhaust throttle valve (exhaust amount adjusting means) 13 arranged in the exhaust path 6 of the engine 2, and the intake throttle valve 12 and the exhaust throttle valve 13. An exhaust purification system 1 for an engine 2 having an ECU (control means) 30 that performs a regeneration means for burning and removing particulates collected by the particulate filter 10, and an operating state of the engine 2 The engine 2 operating state determining means for determining whether the engine is in a steady state or a transient state, the opening degree of the intake throttle valve 12 and the exhaust throttle valve 13, The ECU 30 includes a storage unit (storage unit) 70 in which a relationship map of the rotational speed and load factor of the gin 2 is stored. The ECU 30 refers to the relationship map of the storage unit 70 and the intake throttle valve 12 and / or the exhaust gas. A target opening degree of at least one of the throttle valves 13 is set, and a change speed to the target opening degree is set according to a determination result of the operating state determination means of the engine 2, and the intake throttle valve 12 and / or the exhaust throttle valve is set. The valve 13 is controlled to achieve the target opening at the set change speed.

  With this configuration, it is possible to appropriately regenerate the particulate filter 10 without performing post-injection of the fuel injection valve 4 in the engine 2, and without stopping the operation of the work vehicle that is the engine-equipped device. It will end. Therefore, when the particulate filter 10 is regenerated, the work using the work vehicle can be continued. Further, in this case, the change speed of the valve body when changing the opening degree of the intake throttle valve 12 and the exhaust throttle valve 13 can be set appropriately, so that the color of the exhaust gas accompanying the regeneration of the particulate filter 10 can be changed. It is possible to reduce the occurrence of changes, odors, noise, etc., and to prevent the operator's operating environment from deteriorating.

  Further, in the exhaust purification system 1 for the engine 2 according to the embodiment of the present invention, the storage unit 70 includes the injection timing, the number of injections, the injection pressure, the rotation speed and the load of the engine 2 in the engine 2. The fuel injection relationship map is stored, and the ECU 30 refers to the fuel injection relationship map and determines at least one of the target injection timing, the target injection count, and the target injection pressure of the fuel injection valve 4. In addition to setting, the target injection timing, the target number of injections, and the change speed to the target injection pressure are set in accordance with the determination result of the operating state determination means of the engine 2, and the set change of the fuel injection valve 4 Control is performed so that the injection is performed at at least one of the target injection timing, the target number of injections, and the target injection pressure at a speed.

  With this configuration, the particulate filter 10 can be regenerated more appropriately without post-injecting the fuel injection valve 4 in the engine 2, and the operation of the work vehicle, which is an engine-equipped device, is stopped. You do n’t have to. Therefore, when the particulate filter 10 is regenerated, the work using the work vehicle can be continued. Further, in this case, the change speed when changing the injection timing, the number of injections, and the injection timing of the fuel injection valve 4 can be set appropriately, so that the color change of the exhaust gas accompanying the regeneration of the particulate filter 10 Odor generation or noise generation can be reduced, and deterioration of the operating environment of the operator can be prevented.

  The exhaust purification system 1 for the engine 2 according to an embodiment of the present invention includes a temperature sensor 21 that detects the exhaust gas temperature of the engine 2, and the ECU 30 corresponds to the exhaust gas temperature detected by the temperature sensor 21. Then, one of the intake throttle valve 12 and the exhaust throttle valve 13 is operated, and after the set time has elapsed from the operation of one of the intake throttle valve 12 and the exhaust throttle valve 13, or after the exhaust gas temperature reaches the set temperature, the intake throttle valve 12 or the other of the exhaust throttle valve 13 is operated.

  With this configuration, the particulate filter 10 can be regenerated more appropriately without post-injecting the fuel injection valve 4 in the engine 2, and the operation of the work vehicle, which is an engine-equipped device, is stopped. You do n’t have to. Therefore, when the particulate filter 10 is regenerated, the work using the work vehicle can be continued. Further, it is possible to reduce the color change of the exhaust gas, the generation of odor, the generation of noise, and the like accompanying the regeneration of the particulate filter 10, and the deterioration of the operating environment of the operator can be prevented.

DESCRIPTION OF SYMBOLS 1 Exhaust purification system 2 Engine 3 Intake path 4 Fuel injection valve 5 Cylinder 6 Exhaust path 10 Particulate filter 11 Oxidation catalyst 12 Intake throttle valve 13 Exhaust throttle valve 30 ECU

Claims (2)

A particulate filter arranged in the middle of the exhaust path of the engine and collecting particulates; an intake air amount adjusting means arranged in the intake path of the engine to drive and control an intake throttle actuator; The particulate quantity is controlled by controlling an exhaust amount adjusting means disposed in the exhaust path of the exhaust passage and controlling an exhaust amount by drivingly controlling an exhaust throttle actuator, and the intake amount adjusting means and / or the exhaust amount adjusting means. In an engine exhaust purification system having a regeneration means for burning and removing particulates collected by a filter, an engine load detection sensor, an engine speed detection sensor, and an engine exhaust temperature detection means,
Based on the rotation speed detected by the engine rotation speed detection sensor and the detection result of the load factor detected by the engine load detection sensor, it is determined whether the engine operating state is a steady state or a transient state, and the determination result An engine operating state determining means for selecting a transient filter or a steady filter as an applied filter based on
When the exhaust gas temperature is higher than a predetermined temperature according to the exhaust gas temperature detected by the exhaust gas temperature detecting unit, the control operation of the exhaust gas amount adjusting unit is started and at the same time or after the set time has elapsed, or After the gas temperature reaches the set temperature, the control operation of the intake air amount adjusting means is started, and when the exhaust gas temperature is lower than a predetermined temperature, the control operation of the exhaust air amount adjusting means is started. Alternatively, after the exhaust gas temperature reaches the set temperature, the control operation of the intake air amount adjusting means is started,
Storage means for storing a relationship map for determining the relationship between the engine speed and the load factor and the operation of the intake air amount adjusting means and / or the exhaust gas amount adjusting means is provided. The target operation of the amount adjusting means and / or the exhaust amount adjusting means is set, and the signal is passed using the transient filter or the steady state filter as an applied filter according to the determination result of the engine operating state determining means. To set the speed of change to the target action,
Controlling the intake air amount adjusting means and / or the exhaust air amount adjusting means to control the drive speeds of the intake throttle actuator and the exhaust throttle actuator so as to perform the target operation at the set change speed. A featured engine exhaust gas purification system. 2. The engine exhaust gas purification system according to claim 1, wherein the storage means also stores a fuel injection relation map of an injection timing, an injection frequency, an injection pressure, an engine speed and a load factor of the fuel injection valve. From the relationship map for fuel injection, at least one of the target injection timing of the fuel injection valve, the target number of injections, the target injection pressure is set, and according to the determination result of the engine operating state determination means, The target injection timing, the target number of injections, and the change speed to the target injection pressure are set by passing a signal using the transient filter or the steady filter as an application filter, and the fuel injection actuator of the fuel injection valve The drive speed is controlled with at least one of the target injection timing, the target number of injections, and the target injection pressure at the set change speed. Engine exhaust purification system, characterized in that Unisuru.

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