Playback Control System

Abstract

To suppress the generation of noise resulting from the execution of vehicle stop-time regeneration processing.SOLUTION: A regeneration control system for executing vehicle stop-time regeneration processing for executing the regeneration of a filter 16 arranged at an exhaust passage 12 of an internal combustion engine 10 at a stop of a vehicle comprises a tool control device 200. The tool control device 200 executes: acquisition processing for acquiring dark noise before the execution of the vehicle stop-time regeneration processing; calculation processing for calculating a limit value for limiting an engine rotational speed so that the engine rotational speed during the execution of the vehicle stop-time regeneration processing becomes lower than that in the case that the dark noise is large when the dark noise is small; and indication processing for indicating an operation of the internal combustion engine at the limit value at the execution of the vehicle stop-time regeneration processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a regeneration control system for regenerating a filter provided in an exhaust passage of an internal combustion engine. [Background technology]

[0002] For example, Patent Document 1 describes a control device that executes a vehicle-stop regeneration process that regenerates a filter provided in an exhaust passage of an internal combustion engine while the vehicle is stopped. This control device increases the engine speed when the vehicle-stop regeneration process is being executed, thereby increasing the efficiency of filter regeneration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-183506 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, increasing the engine speed while the vehicle is stopped may result in increased noise for neighboring areas. [Means for solving the problem]

[0005] The regeneration control system for solving the above problem executes a vehicle-stopped regeneration process for regenerating a filter provided in an exhaust passage of an internal combustion engine while the vehicle is stopped. The regeneration control system includes an execution device. The execution device executes an acquisition process for acquiring background noise before the vehicle-stopped regeneration process is executed, a calculation process for calculating a limit value for limiting the engine speed during the vehicle-stopped regeneration process so that the engine speed is lower when the background noise is low than when the background noise is high, and an instruction process for instructing the internal combustion engine to operate according to the limit value when the vehicle-stopped regeneration process is executed.

[0006] According to this configuration, when the vehicle-stopped regeneration process is executed, the engine speed is set to be lower as the background noise decreases, thereby making it possible to suppress the generation of noise accompanying the execution of the vehicle-stopped regeneration process. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a regeneration control system according to an embodiment. [Diagram 2] 4 is a flowchart showing a procedure of a process executed by each control device of the embodiment. [Diagram 3] 4 is a graph showing the correspondence relationship between background noise and a target rotation speed. [Figure 4] 1 is a graph showing the correspondence relationship between background noise and a duty ratio. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of a regeneration control system will be described with reference to FIGS. <Vehicle configuration> As shown in FIG. 1, a vehicle 500 is equipped with an internal combustion engine 10.

[0009] A three-way catalytic device 14 for purifying exhaust gas is provided in an exhaust passage 12 of the internal combustion engine 10. This three-way catalytic device 14 oxidizes and purifies hydrocarbons (HC) and carbon monoxide (CO) contained in the exhaust gas, and also reduces and purifies nitrogen oxides (NOx) contained in the exhaust gas.

[0010] A filter 16 that collects particulate matter (hereinafter, referred to as PM) in the exhaust gas is provided in the exhaust passage 12 at a position downstream of the three-way catalytic device . The cooling system of the internal combustion engine 10 includes a radiator 20 that cools the cooling water of the internal combustion engine 10. The radiator 20 includes an electric fan 22 whose rotation speed is adjusted by duty control.

[0011] The engine control device 100 controls various control values ​​related to engine operation, such as the intake air amount, the injected fuel amount, the ignition timing, the rotation speed of the fan 22, and the like, of the internal combustion engine 10. The engine control device 100 includes a CPU, a memory, a communication port for communicating with an external device, and the like. The communication port may be either wired or wireless. The engine control device 100 receives various information about the vehicle 500 and the internal combustion engine 10, such as the vehicle speed SP of the vehicle 500, the accelerator operation amount ACP, which is the operation amount of the accelerator pedal, the intake air amount GA, and the crank angle signal Scr. The engine control device 100 executes various controls according to the various information by the CPU executing a program stored in the memory. In this embodiment, the engine control device 100 including the CPU and the memory constitutes a first execution device provided in the vehicle 500.

[0012] A service tool 50 that is manually operated by a vehicle mechanic or the like is connected to the engine control device 100 via a wired or wireless connection. The service tool 50 includes a tool control device 200 that includes a CPU, a memory, a communication port for communicating with the engine control device 100, and the service tool 50 also includes an operation switch and a display panel. The tool control device 200 executes various controls by the CPU executing programs stored in the memory. In this embodiment, the tool control device 200 that includes the CPU and memory constitutes a second execution device that is not provided in the vehicle 500.

[0013] The engine control device 100 calculates the engine speed NE based on the crank angle signal Scr. The engine control device 100 also calculates the engine load factor KL based on the engine speed NE and the intake air amount GA.

[0014] The engine control device 100 also calculates a catalyst temperature Tsc, which is the temperature of the three-way catalytic device 14, and a filter temperature Tf, which is the temperature of the filter 16, based on various engine operating conditions such as the engine load factor KL and the engine speed NE. The engine control device 100 also calculates a PM accumulation amount Ps, which is the accumulation amount of particulate matter in the filter 16, based on the engine speed NE, the engine load factor KL, the filter temperature Tf, etc.

[0015] The engine control device 100 then executes regeneration control of the filter 16 in order to burn and remove the PM accumulated on the filter 16 and regenerate the filter 16. This regeneration control is automatically executed by the engine control device 100 when a prescribed execution condition is met, for example, the PM accumulation amount Ps is equal to or greater than a predetermined threshold value α. The regeneration control is also executed when forced regeneration of the filter 16 is requested through manual operation using the service tool 50 while the vehicle 500 is stopped, that is, while the vehicle is stopped. Hereinafter, forced regeneration performed while the vehicle is stopped is referred to as a regeneration process while the vehicle is stopped. If the vehicle 500 is equipped with a switch or the like for requesting forced regeneration, the regeneration process while the vehicle is stopped can also be performed by operating the switch or the like.

[0016] The regeneration control includes a temperature rise control for raising the temperature of the filter 16, and a PM combustion control for burning and removing PM by making the atmosphere of the filter 16, the temperature of which has been raised by the temperature rise control, into an oxidizing atmosphere.

[0017] The engine control device 100 executes, for example, retard control of ignition timing as the temperature rise control. In addition, the engine control device 100 executes, for example, dither control as the temperature rise control, in which the air-fuel ratio of some cylinders of the internal combustion engine 10 is made richer than the theoretical air-fuel ratio to make them rich burn cylinders, and the air-fuel ratio of the remaining cylinders is made leaner than the theoretical air-fuel ratio to make them lean burn cylinders. When this dither control is executed, the reaction between the unburned fuel components and incompletely burned components in the exhaust discharged from the rich burn cylinders and the oxygen in the exhaust discharged from the lean burn cylinders is promoted by the three-way catalyst device 14, and the temperature of the three-way catalyst device 14 is raised. When the temperature of the three-way catalyst device 14 is raised in this way, the temperature of the exhaust passing through the three-way catalyst device 14 rises, and this high-temperature exhaust flows into the filter 16 provided downstream of the three-way catalyst device 14, causing the filter 16 to become hot. Then, when the temperature of the filter 16 becomes equal to or higher than the combustion temperature at which the particulate matter accumulated on the filter 16 is burned, PM combustion control is executed to make the atmosphere of the filter 16 an oxidizing atmosphere. For example, as such PM combustion control, the engine control device 100 executes lean combustion control to burn an air-fuel mixture adjusted to an air-fuel ratio leaner than the stoichiometric air-fuel ratio, and supplies oxygen to the exhaust passage 12. By supplying oxygen in this way, the PM trapped on the filter 16 is burned (oxidized) and removed. Then, when the PM accumulation amount Ps calculated during the execution of the regeneration control becomes equal to or less than a predetermined threshold value β, the engine control device 100 determines that the regeneration of the filter 16 is completed, and ends the regeneration control.

[0018] Here, when the vehicle is stopped while the regeneration process is being performed, the engine control device 100 sets the engine speed to a speed higher than the idle speed to increase the efficiency of the regeneration process. If the engine speed is increased while the vehicle is stopped, the temperature inside the engine compartment may rise, causing heat damage. Therefore, the engine control device 100 increases the rotation speed of the fan 22 when the vehicle is stopped while the regeneration process is being performed to suppress the occurrence of such heat damage.

[0019] Here, if the engine speed or the fan 22 is increased while the vehicle is stopped, there is a concern that noise may be generated in the neighborhood. Therefore, the regeneration control system of this embodiment executes the following process. <Processing performed by the playback control system> 2 shows the procedure of the process executed by the engine control device 100 and the tool control device 200. This process is performed when the communication port of the engine control device 100 and the communication port of the tool control device 200 are connected. This process is started when a switch for executing the regeneration process during stoppage, etc., provided on the service tool 50 is operated. In the following, step numbers are represented by numbers preceded by "S."

[0020] When this process starts, first, the tool control device 200 executes an acquisition process to acquire background noise BN (S100). The background noise BN is the background noise around the vehicle 500 while the vehicle is stopped before the stopped-vehicle regeneration process is executed. This background noise BN is measured by an operator (a vehicle user or a vehicle mechanic) using a sound level meter. Examples of sound level meters include a noise measurement app installed on a smartphone or the like, a commercially available sound level meter, and a microphone for hands-free use provided on the vehicle 500. The operator then manually inputs the measured background noise BN into the service tool 50. The tool control device 200 acquires the input background noise BN through the process of S100.

[0021] Next, the tool control device 200 executes a calculation process to calculate the target rotation speed NEt and the duty ratio DR based on the acquired background noise BN (S110). The target rotation speed NEt is a target value of the engine rotation speed during execution of the stationary-vehicle regeneration process.

[0022] As shown in Fig. 3, the tool control device 200 calculates the target rotation speed NEt using map data or a function formula, etc., so that the target rotation speed NEt is lower as the acquired background noise BN becomes smaller. Note that this target rotation speed NEt is a rotation speed higher than the idle rotation speed. The target rotation speed NEt is a value equivalent to a limit value that limits the engine rotation speed during the execution of the stationary regeneration process so that the engine rotation speed becomes lower as the background noise becomes smaller.

[0023] The duty ratio DR is the duty ratio of the voltage applied to the fan 22 during execution of the stationary-vehicle regeneration process. 4, the tool control device 200 calculates the duty ratio DR using map data or a function formula, etc., so that the smaller the acquired background noise BN, the smaller the duty ratio DR becomes, that is, the lower the rotation speed of the fan 22. This duty ratio DR is a value equivalent to a limit value that limits the rotation speed of the fan 22 so that the smaller the background noise, the lower the rotation speed of the fan 22 during the execution of the stationary regeneration process becomes.

[0024] Next, the tool control device 200 transmits data to the engine control device 100 (S120). The data transmitted at this time is the above-mentioned target rotation speed NEt, duty ratio DR, and a command value instructing the start of execution of regeneration control. The process of S120 corresponds to an instruction process for instructing the operation of the internal combustion engine with the limit value when executing the stationary regeneration process.

[0025] In the process of S130, the engine control device 100 receives the above data. Then, execution of the above-mentioned regeneration control is started (S150). During execution of the regeneration control, the engine control device 100 controls the engine rotation speed so as to become the above-mentioned target rotation speed NEt. Also, during execution of the regeneration control, the engine control device 100 sets the duty ratio of the voltage applied to the fan 22 to the above-mentioned duty ratio DR.

[0026] Next, the engine control device 100 judges whether or not the regeneration of the filter 16 is completed (S150). If it is judged that the regeneration of the filter 16 is not completed (S150: NO), the engine control device 100 repeatedly executes the process of S150.

[0027] On the other hand, when it is determined in the process of S150 that the regeneration of the filter 16 is completed (S150: YES), the engine control device 100 transmits a regeneration completion signal indicating that the regeneration is completed to the tool control device 200 (S160). When it is determined that the regeneration of the filter 16 is completed, the engine control device 100 ends the regeneration control as described above. Then, the engine control device 100 performs a process of returning the engine rotation speed and the rotation speed of the fan 22 to normal values, for example, an idle rotation speed or a rotation speed of the fan 22 according to the temperature of the cooling water.

[0028] In the process of S170, the tool control device 200 receives the regeneration completion signal. Then, the tool control device 200 executes a process of notifying the completion of regeneration (S180). The notification method at this time may be, for example, displaying the regeneration completion on a display panel of the service tool 50 or emitting a sound notifying the completion of regeneration.

[0029] <Action and Effects> According to this embodiment, the following actions and effects can be obtained. (1) When the vehicle-stop regeneration process is executed, the engine speed of the internal combustion engine 10 is set to be lower as the background noise BN becomes smaller. Therefore, the generation of noise from the internal combustion engine 10 accompanying the execution of the vehicle-stop regeneration process can be suppressed.

[0030] (2) When the vehicle-stopped regeneration process is executed, the smaller the background noise BN is, the lower the rotation speed of the fan 22 is set. Therefore, the generation of noise from the fan 22 due to the execution of the vehicle-stopped regeneration process can be suppressed.

[0031] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0032] The above-mentioned target rotation speed NEt is set as the upper limit value NEmax of the engine rotation speed during the vehicle stop regeneration process. Then, during the vehicle stop regeneration process, a process may be executed to limit the engine rotation speed to a rotation speed equal to or lower than the upper limit value NEmax. Even in this case, the same action and effect as in (1) above can be obtained.

[0033] Similarly, the above-mentioned duty ratio DR is set as the upper limit value DRmax of the duty ratio of the fan 22 during the execution of the stationary regeneration process. Then, during the execution of the stationary regeneration process, a process may be executed to limit the duty ratio of the fan 22 to the upper limit value DRmax. Even in this case, the same action and effect as in (2) above can be obtained.

[0034] 2, the duty ratio DR is calculated based on the background noise BN, but the calculation of the duty ratio DR may be omitted. Even in this case, the action and effect described in (1) above can be obtained.

[0035] The rotation speed of the fan 22 may be controlled by a method other than duty control. Even in this case, the action and effect equivalent to the above (2) can be obtained by controlling the rotation speed of the fan 22 so that the rotation speed becomes slower as the background noise BN becomes smaller.

[0036] The background noise BN is measured and manually input into the service tool 50. Alternatively, a sound level meter may be built into or connected to the service tool 50. Then, the tool control device 200 may obtain the background noise BN directly from the sound level meter.

[0037] Although the above-mentioned calculation processing and instruction processing are performed by the tool control device 200, these processing may be performed by the engine control device 100. All of the processing shown in FIG. 2 may be performed by the engine control device 100.

[0038] The engine control device 100 and the tool control device 200 are not limited to those equipped with a CPU and a memory and executing software processing. For example, they may be equipped with a dedicated hardware circuit (e.g., ASIC, etc.) that processes at least a part of the software processing executed in the above embodiment. That is, the engine control device 100 and the tool control device 200 may have any of the following configurations (a) to (c). (a) They are equipped with a processing device that executes all of the above processing according to a program, and a program storage device such as a memory that stores the program. (b) They are equipped with a processing device and a program storage device that executes part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (c) They are equipped with a dedicated hardware circuit that executes all of the above processing. Here, the software processing circuit equipped with the processing device and the program storage device and the dedicated hardware circuit may be multiple. That is, the above processing may be executed by a processing circuit equipped with at least one of one or more software processing circuits and one or more dedicated hardware circuits. [Explanation of symbols]

[0039] 10. Internal combustion engine 12...Exhaust passage 14...Three-way catalyst device 16…Filter 20…Radiator 22...Fan 50…Service tools 100...Engine control device 200...Tool control device 500…Vehicle

Claims

[Claim 1] An internal combustion engine, a radiator, and an execution device, The radiator has an electric fan whose rotation speed is adjustable, A regeneration control system that executes a vehicle-stopped regeneration process for regenerating a filter provided in an exhaust passage of the internal combustion engine while the vehicle is stopped, The execution device is An acquisition process for acquiring background noise before execution of the regeneration process during a stop; a calculation process for calculating a first limit value for limiting the engine rotation speed of the internal combustion engine during execution of the stationary regeneration process so that the engine rotation speed is lower when the background noise is small than when the background noise is large, and for calculating a second limit value for limiting the fan rotation speed during execution of the stationary regeneration process so that the fan rotation speed is lower when the background noise is small than when the background noise is large; When the vehicle-stop regeneration process is executed, an instruction process is executed to instruct the internal combustion engine to operate at the first limit value and to instruct the fan to operate at the second limit value. Playback control system.

Images