WO2013183365A1

WO2013183365A1 - Internal combustion engine diagnostic apparatus and diagnostic method

Info

Publication number: WO2013183365A1
Application number: PCT/JP2013/061169
Authority: WO
Inventors: 北村　元; 民一木村
Original assignee: 日産自動車株式会社
Priority date: 2012-06-06
Filing date: 2013-04-15
Publication date: 2013-12-12

Abstract

A diagnostic apparatus for diagnosing whether internal combustion engine operation control for warming up an exhaust purifying catalyst is being normally implemented includes: a diagnostic timing determination unit for determining a diagnostic timing on the basis of the presence or absence of a command for making the engine rotation speed higher than usual to warm up the exhaust purifying catalyst, or of an activation command for a device activated to enable a retard amount to be increased when the engine ignition timing is retarded from a normal timing to warm up the exhaust purifying catalyst; and a diagnosis implementation unit that determines whether control for warming up the exhaust purifying catalyst is being implemented normally at the diagnostic timing.

Description

Diagnostic apparatus and diagnostic method for internal combustion engine

The present invention relates to a diagnostic apparatus and a diagnostic method for diagnosing whether or not operation control of an internal combustion engine for warming up an exhaust purification catalyst is being executed normally.

The catalyst exhaust purification capacity is low when the vehicle is cold-started. Therefore, the exhaust gas purification capability of the catalyst is increased early by warming up the catalyst by raising the exhaust temperature by controlling the operation of the internal combustion engine. When such catalyst warm-up control is not normally performed at the time of cold start, harmful gas is discharged into the atmosphere. Therefore, a diagnostic device for diagnosing an abnormality in the catalyst warm-up control has been proposed (see JP2009-25718A).

However, the conventional diagnostic device described above sometimes makes a false diagnosis regarding catalyst warm-up control.

The present invention was made paying attention to such conventional problems. An object of the present invention is to accurately diagnose operation control of an internal combustion engine for warming up an exhaust purification catalyst.

The diagnostic device according to the present invention is a device that diagnoses whether or not the operation control of the internal combustion engine for warming up the exhaust purification catalyst is being executed normally. This diagnostic device determines a retard amount when a command for increasing the rotational speed of the engine to be higher than usual in order to warm up the exhaust purification catalyst or when retarding the ignition timing of the engine in order to warm up the exhaust purification catalyst. A determination unit is included that determines the diagnosis time based on the presence / absence of an operation command of an apparatus that is operated to enable expansion. And it is characterized by further including the execution part which diagnoses whether the control which warms up an exhaust gas purification catalyst is normally performed when it is a diagnosis time.

Embodiments of the present invention and advantages of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an internal combustion engine diagnostic apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing a processing procedure of a diagnostic method performed by the diagnostic apparatus. FIG. 3 is a timing chart showing an example of a diagnostic method.

(First embodiment)
FIG. 1 is a functional configuration diagram showing an internal combustion engine diagnostic apparatus according to an embodiment of the present invention. FIG. 1 shows a diagnostic device 100 constituting the control unit 1 and a configuration related to the diagnostic device 100.

The control unit 1 controls the internal combustion engine according to the state of the vehicle. For example, the control unit 1 executes operation control (hereinafter referred to as “catalyst warm-up control”) for warming up an exhaust purification catalyst (not shown) when the vehicle is cold-started.

The control unit 1 includes a valve operating angle / lift continuously variable control unit (hereinafter referred to as “VEL (Valve Event and Lift) control unit”) 10, a retard control unit 20, and an engine rotation control unit 30. The control unit 1 further includes a tumble control valve control unit (hereinafter referred to as “TCV control unit”) 40, a valve timing control unit (hereinafter referred to as “VTC unit”) 50, and a diagnostic device 100. The control unit 1 includes a neutral switch (hereinafter referred to as “NEUT switch”) 71, a water temperature sensor 72, an engine rotation speed sensor 73, and an engine load sensor 74.

The NEUT switch 71 is used for diagnosis of catalyst warm-up control, and detects the neutral (N) and parking (P) states of the vehicle. The NEUT switch 71 supplies position information indicating the detected state to the diagnostic apparatus 100.

The water temperature sensor 72 detects the temperature of the cooling water that cools the internal combustion engine. The water temperature sensor 72 supplies water temperature information indicating the detected water temperature to the diagnostic apparatus 100.

The engine speed sensor 73 detects the engine speed of the internal combustion engine. The engine rotation speed sensor 73 supplies engine rotation speed information indicating the detected engine rotation speed to the diagnosis apparatus 100.

The engine load sensor 74 detects the engine load of the internal combustion engine. The engine load sensor 74 supplies engine load information indicating the detected engine load to the diagnostic device 100.

Diagnostic device 100 diagnoses whether or not catalyst warm-up control is normally executed at the time of cold start. Such diagnosis is referred to as, for example, Cold Start Strategy diagnosis (hereinafter abbreviated as “CSS diagnosis”).

Diagnostic apparatus 100 acquires position information, water temperature information, engine rotation speed information, and engine load information from NEUT switch 71, water temperature sensor 72, engine rotation speed sensor 73, and engine load sensor 74, respectively. The diagnosis device 100 diagnoses an abnormality in the catalyst warm-up control using detection information such as position information, water temperature information, engine rotation speed information, engine load information, and the like.

In the present embodiment, the diagnostic device 100 determines whether or not the catalyst warm-up control executed by the VEL control unit 10, the retard control unit 20, the engine rotation control unit 30, the TCV control unit 40, and the VTC unit 50 is operating normally. Determine whether.

The VEL control unit 10 controls a VEL system provided in the internal combustion engine. The VEL control unit 10 includes a command execution unit 11 and a valve timing information holding unit 12.

The command execution unit 11 adjusts the valve operating angle and the lift amount of the VEL system according to the state of the vehicle. The command execution unit 11 records a command value for the VEL system in the valve timing information holding unit 12.

The valve timing information holding unit 12 holds valve timing information indicating the valve timing recorded by the command execution unit 11.

The retard control unit 20 retards the ignition timing of the internal combustion engine from the reference ignition timing in order to warm up the exhaust purification catalyst as one of the catalyst warm-up controls. As a result, the ratio of unburned fuel contained in the exhaust gas increases, the unburned fuel discharged from the internal combustion engine to the exhaust gas purification catalyst is burned back, and high-temperature exhaust gas flows to the exhaust gas purification catalyst. For this reason, the exhaust purification catalyst is raised to a temperature at which the exhaust purification action functions.

The retard control unit 20 includes a warm-up command execution unit 21 and a retard flag holding unit 22.

When the warm-up command execution unit 21 receives a request for catalyst warm-up, the warm-up command execution unit 21 issues a retard command that retards the ignition timing of the spark plug provided in the internal combustion engine from the reference ignition timing.

Specifically, the warm-up command execution unit 21 periodically acquires state information such as water temperature information indicating engine water temperature, atmospheric pressure information indicating atmospheric pressure, and information held in the valve timing information holding unit 12. . Then, the warm-up command execution unit 21 determines whether or not each of the acquired state information satisfies a retard command condition that indicates a predetermined water temperature condition, atmospheric pressure condition, valve timing condition that can be retarded, and the like. To do.

When each state information satisfies the retard command condition, the warm-up command execution unit 21 retards the ignition timing more than usual to warm up the exhaust purification catalyst by the retard command, and is held in the retard flag holding unit 22. Set the flag to “1”.

The retard flag holding unit 22 receives a signal from the warm-up command execution unit 21 and holds a retard flag indicating whether or not the ignition timing retard command is present. In the present embodiment, the retard flag is set to “1” when a retard command is issued, and is set to “0” when the retard command is canceled.

The engine rotation control unit 30 controls the engine rotation speed in accordance with the operation control of the internal combustion engine. As one of the catalyst warm-up controls, the engine rotation control unit 30 increases the engine rotation speed at the time of cold start than the engine rotation speed in the normal idle state. As a result, the exhaust gas temperature rises, so that the exhaust gas purification catalyst is warmed up early.

The engine rotation control unit 30 includes a warm-up command execution unit 31 and a rotation Up flag holding unit 32.

The warm-up command execution unit 31 commands the internal combustion engine to increase the engine speed more than usual in order to warm up the exhaust purification catalyst.

Specifically, the warm-up command execution unit 31 periodically acquires intake air information indicating the intake air temperature of the internal combustion engine, position information from the NEUT switch 71, and state information such as water temperature information. Then, the warm-up command execution unit 31 determines whether or not each of the acquired state information satisfies a rotation up command condition in which a predetermined intake condition, neutral or parking condition, water temperature condition, and the like are indicated. For example, a water temperature condition of 5 to 40 degrees and an intake condition of 5 to 20 degrees are set in the rotation Up command condition.

When each state information satisfies the rotation up command condition, the warm-up command execution unit 31 increases the engine rotation speed to warm up the exhaust purification catalyst, and sets the flag held in the rotation up flag holding unit 32 as “ Set to “1”.

The rotation Up flag holding unit 32 receives a signal from the warm-up command execution unit 31 and holds a rotation Up flag indicating whether or not there is a rotation Up command. In this embodiment, the rotation up flag is set to “1” when there is an engine rotation up command, and is set to “0” when the rotation up command is canceled.

The TCV control unit 40 drives a flow control valve that enhances the flow of intake air to the internal combustion engine. The flow control valve is, for example, a tumble control valve or a swirl control valve. When the TCV control unit 40 controls the tumble control valve, the flow of intake air is increased, and the combustion efficiency of the internal combustion engine is increased. Therefore, the retard amount from the reference ignition timing can be made larger than when no tumble control valve is provided while suppressing misfire in the internal combustion engine. The higher the retard amount, the easier the hot exhaust gas flows to the exhaust purification catalyst. That is, the flow control valve is a device that is operated so as to allow an increase in the amount of retard when the ignition timing of the engine is retarded more than usual in order to warm up the exhaust purification catalyst.

In the present embodiment, the TCV control unit 40 closes the tumble control valve by the catalyst warm-up control, so that the retard amount set by the warm-up command execution unit 21 is made larger than usual while preventing the occurrence of misfire. As a result, the exhaust purification catalyst at the time of cold start can be warmed more quickly.

The TCV control unit 40 includes a warm-up command execution unit 41 and a flow strengthening flag holding unit 42.

The warm-up command execution unit 41 issues a flow strengthening command (operation command) to the tumble control valve in order to retard the ignition timing of the internal combustion engine more than usual as one of the catalyst warm-up controls.

Specifically, the warm-up command execution unit 41 periodically acquires state information such as oil temperature information indicating the temperature of the engine oil, time since the engine was started, and water temperature information. Then, the warm-up command execution unit 41 determines whether each of the acquired state information satisfies a flow strengthening command condition indicating a predetermined oil temperature condition, a standby time until the oil reaches an appropriate temperature, a water temperature condition, and the like. Judge whether or not.

When each state information satisfies the flow enhancement command condition, the warm-up command execution unit 41 drives the tumble control valve according to the flow enhancement command and sets the flag held in the flow enhancement flag holding unit 42 to “1”. .

The flow strengthening flag holding unit 42 receives a signal from the warm-up command execution unit 41 and holds a flow strengthening flag indicating the presence or absence of the flow strengthening command. In this embodiment, the flow strengthening flag is set to “1” when the flow strengthening command is issued, and is set to “0” when the flow strengthening command is canceled.

The VTC unit 50 controls a variable valve gear that changes the opening / closing timing of the intake valve or the exhaust valve. The VTC unit 50 sets the valve timing of the variable valve so that the retard amount set by the warm-up command execution unit 21 is larger than usual. As a result, the amount of retard is increased, so that the exhaust purification catalyst can be quickly warmed at the time of cold start as in the TCV control unit 40. Further, by advancing the exhaust timing of the variable valve, the proportion of unburned fuel contained in the exhaust increases, so the time required for warming up the exhaust purification catalyst is further shortened. That is, the variable valve operating device is a device that is operated so as to increase the amount of retard when the ignition timing of the engine is retarded more than usual in order to warm up the exhaust purification catalyst.

The VTC unit 50 includes a warm-up command execution unit 51 and a retard amount expansion flag holding unit 52.

As one of the catalyst warm-up controls, the warm-up command execution unit 51 issues a retard amount expansion command (operation command) to the variable valve in order to retard the ignition timing than when the VTC unit 50 is not provided.

Specifically, the warm-up command execution unit 51 periodically acquires state information such as water temperature information. Then, the warm-up command execution unit 41 determines whether each of the acquired state information satisfies a change command condition indicating a predetermined water temperature condition or the like.

When each state information satisfies the valve timing change command condition, the warm-up command execution unit 51 changes the valve timing of the variable valve to increase the retard amount and is held in the retard amount increase flag holding unit 52. Set the flag to “1”.

The retard amount expansion flag holding unit 52 receives a signal from the warm-up command execution unit 51 and holds a retard amount expansion flag indicating whether or not there is a retard amount expansion command. In this embodiment, the retard amount enlargement flag is set to “1” when the retard amount enlargement command is issued, and is set to “0” when the retard amount enlargement command is canceled.

Thus, the retard control unit 20, the engine rotation control unit 30, the TCV control unit 40, and the VTC unit 50 each perform catalyst warm-up control for warming up the exhaust purification catalyst. If the exhaust purification catalyst does not warm up normally due to a failure of a device such as a flow control valve or a variable valve provided in the internal combustion engine or an abnormality in the catalyst warm-up control itself, Exhaust gas is not purified and harmful gases are discharged into the atmosphere.

Therefore, a diagnostic device for diagnosing abnormalities in catalyst warm-up control has been proposed. This diagnostic device may make a diagnosis even when the catalyst warm-up control is not being executed. Therefore, the catalyst warm-up control may be erroneously determined to be abnormal even though the catalyst warm-up control is stopped.

Therefore, the present invention determines whether or not the catalyst warm-up control is normal based on the command for the catalyst warm-up control executed by the retard control unit 20, the engine rotation control unit 30, the TCV control unit 40, and the VTC unit 50. Is going to be diagnosed.

In the present embodiment, the diagnosis device 100 diagnoses whether the catalyst warm-up control is normal based on the retard command, the rotation Up command, the flow enhancement command, and the retard amount increase command as the commands for the catalyst warm-up control. To do. The diagnosis apparatus 100 includes a diagnosis time determination unit 110 and a diagnosis execution unit 120.

The diagnosis time determination unit 110 determines the diagnosis time based on the command flags held in the retard flag holding unit 22, the rotation up flag holding unit 32, the flow enhancement flag holding unit 42, and the retard amount expansion flag holding unit 52.

Specifically, the diagnosis time determination unit 110 acquires flag information indicated by the command flag from the retard flag holding unit 22, the rotation Up flag holding unit 32, the flow strengthening flag holding unit 42, and the retard amount expansion flag holding unit 52. The diagnosis time determination unit 110 acquires position information from the NEUT switch 71.

The diagnosis timing determination unit 110 determines that the catalyst warm-up control is being performed when all the flag information is “1” and the position information indicates neutral or parking at the time of cold start. . When the diagnosis timing determination unit 110 determines that the catalyst warm-up control is being executed, the diagnosis timing determination unit 110 supplies a permission signal for permitting diagnosis to the diagnosis execution unit 120.

On the other hand, the diagnosis time determination unit 110 determines that the catalyst warm-up control is not executed when any of the flag information is “0” or when the position information indicates a state other than neutral or parking. . When the diagnosis timing determination unit 110 determines that the catalyst warm-up control is not being performed, the diagnosis timing determination unit 110 supplies a prohibition signal for prohibiting the diagnosis to the diagnosis execution unit 120.

The diagnosis execution unit 120 diagnoses whether or not the catalyst warm-up control for controlling the internal combustion engine is normally executed at the diagnosis time.

Specifically, the diagnosis execution unit 120 stops the catalyst warm-up control diagnosis while receiving the prohibition signal from the diagnosis time determination unit 110. When receiving the permission signal, the diagnosis execution unit 120 starts diagnosis of whether the catalyst warm-up control is normal.

The diagnosis execution unit 120 acquires water temperature information from the water temperature sensor 72, acquires engine rotation speed information from the engine rotation speed sensor 73, and acquires engine load information from the engine load sensor 74, for example, every few milliseconds. The diagnosis execution unit 120 calculates a calorific value diagnostic parameter related to the amount of heat and a function diagnostic parameter related to the ignition function based on diagnostic information such as water temperature information, engine rotation speed information, and engine load information. The diagnosis execution unit 120 integrates the calculated diagnosis parameters for each of the calorific value diagnosis parameter and the function diagnosis parameter until a predetermined diagnosis period, for example, 10 seconds elapses after receiving the permission signal.

The diagnosis execution unit 120 determines whether or not the catalyst warm-up control is normally executed based on the integrated heat quantity diagnosis parameter and function diagnosis parameter.

Specifically, the diagnosis execution unit 120 determines whether or not the accumulated heat quantity diagnosis parameter exceeds a predetermined heat quantity threshold value. Furthermore, the diagnosis execution unit 120 determines whether or not the accumulated function diagnosis parameter exceeds a predetermined function threshold value. Then, the diagnosis execution unit 120 determines that the catalyst warm-up control is abnormal when the accumulated heat amount diagnosis parameter exceeds the heat amount threshold value or when the accumulated function diagnosis parameter exceeds the function threshold value. . On the other hand, when the integrated calorific value diagnostic parameter does not exceed the function threshold value, the diagnosis execution unit 120 determines that the catalyst warm-up control is normally executed when the integrated function diagnosis parameter does not exceed the function threshold value. judge.

As described above, the diagnosis timing determination unit 110 determines the diagnosis timing at which the catalyst warm-up control is executed based on the presence / absence of a command for the catalyst warm-up control, and the diagnosis execution unit 120 detects the catalyst warm-up at the diagnosis timing. Diagnose whether the control is executed normally. For this reason, the diagnostic device 100 can accurately diagnose an abnormality in the catalyst warm-up control.

FIG. 2 is a flowchart showing a processing procedure of a diagnostic method performed by the diagnostic apparatus 100.

First, in step S911, the control unit 1 determines whether or not the ignition key is set to “On” by the driver.

If the ignition key is set from “Off” to “On”, in step S912, the diagnosis timing determination unit 110 waits until a standby time required for executing the catalyst warm-up control, for example, 5 seconds elapses. The diagnosis time is not judged.

When the standby time has elapsed, in step S913, the diagnosis timing determination unit 110 checks a command flag indicating whether or not there is a command for catalyst warm-up control.

In step S914, the diagnosis timing determination unit 110 refers to the command flag held in the retard flag holding unit 22 and determines whether or not there is a retard command. When the retard flag indicates “0”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control is not being executed, and returns to step S912. On the other hand, when the retard flag indicates “1”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control based on the retard command is being executed.

After confirming the retard command, the diagnosis time determination unit 110 refers to the command flag held in the flow strengthening flag holding unit 42 in step S915 to determine whether or not there is a flow strengthening command. When the flow enhancement flag indicates “0”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control is not being executed, and returns to step S912. On the other hand, when the flow enhancement flag indicates “1”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control based on the flow enhancement command is being executed.

After confirming the flow strengthening command, the diagnosis time determination unit 110 refers to the command flag held in the retard amount expansion flag holding unit 52 in step S916 to determine whether or not there is a retard amount expansion command. If the retard amount expansion flag indicates “0”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control is not being executed, and returns to step S912. On the other hand, when the retard amount increase flag indicates “1”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control based on the retard amount increase command is being executed.

During execution of the flow enhancement command and the retard amount expansion command, the diagnosis timing determination unit 110 refers to the command flag held in the rotation up flag holding unit 32 in step S917 and determines whether or not there has been an engine rotation up command. to decide. When the rotation up flag indicates “0”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control is not being executed, and returns to step S912. On the other hand, when the rotation Up flag indicates “1”, the diagnosis timing determination unit 110 determines that the catalyst warm-up control based on the rotation Up command is being executed.

Then, the diagnosis time determination unit 110 supplies a diagnosis start permission signal to the diagnosis execution unit 120 when all of the retard flag, the flow strengthening flag, the retard amount expansion flag, and the rotation up flag are “1”. To do.

When the diagnosis execution unit 120 receives the permission signal from the diagnosis timing determination unit 110 in step S918, the diagnosis execution unit 120 diagnoses whether or not the catalyst warm-up control is normally executed, and a series of diagnosis methods performed by the diagnosis apparatus 100. The processing procedure ends.

Thus, the diagnosis time determination unit 110 determines the diagnosis time based on the presence / absence of a command for catalyst warm-up control for the internal combustion engine. Then, the diagnosis execution unit 120 diagnoses the internal combustion engine at the diagnosis time specified by the diagnosis time determination unit 110. For this reason, the diagnosis apparatus 100 can start diagnosis only when the catalyst warm-up control is being executed. Therefore, the diagnosis device 100 can prevent the diagnosis execution unit 120 from determining that the catalyst warm-up control is abnormal even though the catalyst warm-up control is stopped. Next, a specific operation of the diagnostic apparatus 100 will be described with reference to the drawings.

FIG. 3 is a timing chart showing an example of a diagnostic method by the diagnostic apparatus 100. The diagnostic apparatus 100 executes a CSS diagnosis.

FIG. 3A is a diagram showing engine rotation speed information from the engine rotation speed sensor 73. FIG. 3B is a diagram showing water temperature information from the water temperature sensor 72. FIG. 3C is a diagram illustrating position information from the NEUT switch 71. FIG. 3D is a diagram illustrating the command flag held in the retard flag holding unit 22. FIG. 3E is a diagram showing command flags held in the rotation up flag holding unit 32 of the engine. FIG. 3F is a diagram showing an increase amount of the engine rotation speed.

FIG. 3 (G) is a diagram illustrating a CSS diagnosis permission signal from the diagnosis time determination unit 110. FIG. 3H is a diagram illustrating timing at which determination by the diagnosis execution unit 120 is permitted. FIG. 3I is a diagram showing the calorific value diagnostic parameters calculated by the diagnostic execution unit 120. FIG. 3J is a diagram illustrating the function diagnosis parameters calculated by the diagnosis execution unit 120. FIG. 3K is a diagram illustrating timing at which the diagnosis in the diagnosis execution unit 120 ends. In FIGS. 3A to 3K, the horizontal axis is a common time axis.

When the ignition key is set from “Off” to “On” at time t 0, in the engine rotation control unit 30, the warm-up command execution unit 31 performs an exhaust purification catalyst on the internal combustion engine based on state information such as water temperature information. Command the rotation Up to warm up the engine. Further, the warm-up command execution unit 31 sets the rotation up flag to “1” as shown in FIG. 3 (E), and the up amount determined by the catalyst warm-up control as shown in FIG. 3 (F). To accelerate the engine speed. As a result, after the engine is started, the engine speed increases as shown in FIG. 3A, and the engine water temperature gradually increases as shown in FIG. 3B as the engine speed increases.

Further, after the engine is started, in the VTC unit 50, when the warm-up command execution unit 51 determines that the change command condition is satisfied based on the state information such as the water temperature information, the VTC unit 50 issues a retard amount increase command. . The warm-up command execution unit 51 sets the retard amount expansion flag to “1”, advances the intake VTC, and advances the exhaust VTC. By controlling the advance of the intake VTC, the intake valve closing timing IVC (Intake Valve Close) approaches the intake bottom dead center BDC (Bottom Dead Centre), the effective compression ratio increases, and the combustion stabilizes. Is possible. Further, by controlling the advance angle of the exhaust VTC, the exhaust valve opening timing EVO (Exhaust Valve Open) is advanced, so that the proportion of unburned fuel contained in the exhaust increases, and this increases after-burning and the exhaust temperature rises. .

When the engine water temperature or the like satisfies the start condition at time t1, the diagnosis time determination unit 110 determines the diagnosis time after a predetermined standby time has elapsed as shown in FIG.

At the time t2 during the standby time, the retard control unit 20 satisfies the retard command condition for warming up the exhaust purification catalyst because the state information such as the water temperature information satisfies the ignition timing retard. Is commanded. Further, the warm-up command execution unit 31 sets the retard flag to “1” as shown in FIG. If the retard command condition is not satisfied, the retard flag remains “0”.

At time t3 when the standby time has elapsed, the diagnosis time determination unit 110 checks the command flag and the position information of the NEUT switch 71. At time t3, both the retard flag and the rotation Up flag indicate “1” as shown in FIGS. 3D and 3E, and the position information is neutral (N as shown in FIG. 3C). ) Or parking (P). Therefore, the diagnosis time determination unit 110 determines that the CSS diagnosis permission condition is satisfied, and supplies a CSS diagnosis permission signal to the diagnosis execution unit 120 as shown in FIG. Conventionally, the CSS diagnosis is unconditionally started from time t3 when the standby time has elapsed.

Upon receiving the permission signal, the diagnosis execution unit 120 calculates a calorific value diagnosis parameter and a function diagnosis parameter as shown in FIGS. 3I and 3J, and the calculated diagnosis parameter for each diagnosis parameter. Is accumulated until the diagnosis period elapses.

At time t4 after the diagnosis period, the permission signal is canceled as shown in FIG. 3 (G), and as shown in FIG. 3 (H), the diagnosis execution unit 120 displays the accumulated calorific value diagnosis parameter and function diagnosis parameter. Based on this, it is determined whether or not the catalyst warm-up control is normal.

Specifically, as shown in FIG. 3I, the diagnosis execution unit 120 determines whether or not the integrated calorific value diagnosis parameter is larger than the calorific value threshold Th1 of the CSS diagnosis. Further, as shown in FIG. 3J, the diagnosis execution unit 120 determines whether or not the integrated function diagnosis parameter is within a normal range from the CSS function threshold Th3 to the function threshold Th2.

For example, when the catalyst warm-up control is normally executed, the exhaust gas temperature flowing through the exhaust purification catalyst becomes high, so that the calorific value diagnosis parameter increases with time as shown in FIG. In addition, when the catalyst warm-up control itself is not normally executed or when the device to be commanded for the catalyst warm-up control, for example, the tumble control valve is not driven due to a failure, the calorific value diagnosis parameter does not become larger than the calorific value threshold Th1. . When there is a failure in the ignition function of the internal combustion engine, the function diagnosis parameter does not converge within the normal range (Th3 to Th2).

At time t4, since the integrated heat quantity diagnosis parameter is larger than the heat quantity threshold Th1 and the integrated function diagnosis parameter is within the normal range, the diagnosis execution unit 120 performs the catalyst warm-up control normally. It is determined that Note that if either the accumulated heat quantity diagnosis parameter or the accumulated function diagnosis parameter exceeds the normal range, the diagnosis execution unit 120 determines that the catalyst warm-up control is abnormal.

After it is determined that the catalyst warm-up control is normally executed, the diagnosis execution unit 120 outputs the determination result to the diagnosis time determination unit 110 together with the end signal indicating the end of the diagnosis, as shown in FIG. To do. Thereafter, since the catalyst warm-up control is finished and the rotation Up command and the retard command are released, the rotation Up flag and the retard flag indicate “0” at time t5.

As described above, the diagnostic device 100 does not start the CSS diagnosis unconditionally after the standby time from the time t2 to the time t3 has elapsed, and both the retard flag and the rotation Up flag are all “1”. When both are “1”, the CSS diagnosis is executed. That is, the diagnosis apparatus 100 starts the CSS diagnosis only when the catalyst warm-up control is being executed.

Further, at the time of cold start, as shown in FIG. 3E, rotation up control is normally started immediately after the start, so rotation up control is performed at time t3 when the standby time has elapsed. However, when the atmospheric pressure is extremely high or extremely low, or when the intake air temperature is extremely high or extremely low, the rotation up control is performed even in cold start, unlike FIG. It may not be done. In such a case, since the CSS diagnosis has been started unconditionally in the past, erroneous diagnosis has occurred. However, since the diagnosis device 100 checks whether the permit condition for the CSS diagnosis is satisfied at time t3, the rotation Up control is performed. It is possible to avoid starting the CSS diagnosis when the process is not performed.

According to the present embodiment, the diagnosis timing determination unit 110 instructs the engine speed to be higher than normal in order to warm up the exhaust purification catalyst, or the engine ignition timing in order to warm up the exhaust purification catalyst. The diagnosis time is determined based on the presence / absence of an operation command of a device that is operated so that the amount of retard can be increased when retarding the valve more than usual. Then, the diagnosis execution unit 120 diagnoses whether or not the control for warming up the exhaust purification catalyst is normally executed at the diagnosis time.

For this reason, the diagnostic device 100 diagnoses whether or not the control for warming up the exhaust purification catalyst is normally executed when there is a command for executing the control for warming up the exhaust purification catalyst. Therefore, the diagnosis device 100 does not start diagnosis when the control for warming up the exhaust purification catalyst is stopped, so that it can accurately diagnose the control for warming up the exhaust purification catalyst.

In the present embodiment, the diagnosis time determination unit 110 may determine the diagnosis time based on the presence or absence of a flow enhancement command for the flow control valve that enhances the flow of intake air. Also in this case, the diagnosis time determination unit 110 can accurately identify the time when the retard control unit 20 is executing the retard control by the flow strengthening command. Therefore, the diagnosis time determination unit 110 can accurately determine the diagnosis time when the catalyst warm-up control is being executed.

Furthermore, in this embodiment, the diagnosis time determination unit 110 may determine the diagnosis time based on the presence / absence of a retard amount expansion command for the variable valve operating apparatus. Also in this case, the diagnosis time determination unit 110 can accurately specify the time when the retard control is executed by the retard amount expansion command. Therefore, the diagnosis time determination unit 110 can accurately determine the diagnosis time when the catalyst warm-up control is being executed.

The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

In addition, the said embodiment can be combined suitably.

This application claims priority based on Japanese Patent Application No. 2012-128615 filed with the Japan Patent Office on June 6, 2012, the entire contents of which are incorporated herein by reference.

Claims

An apparatus for diagnosing whether or not the operation control of the internal combustion engine for warming up the exhaust purification catalyst is being executed,
A command to increase the engine speed to warm up the exhaust purification catalyst, or to increase the retard amount when retarding the ignition timing of the engine to warm up the exhaust purification catalyst. A determination unit for determining the diagnosis time based on the presence or absence of an operation command of the device to be operated as much as possible;
An execution unit for diagnosing whether or not the control for warming up the exhaust purification catalyst is normally executed at the time of diagnosis;
Diagnostic device including
The diagnostic device according to claim 1,
The device that is operated to enable the expansion of the retard amount is a flow control valve that enhances the flow of intake air,
The determination unit determines a diagnosis time based on the presence or absence of an operation command for the flow control valve.
Diagnostic device.
In the diagnostic device according to claim 1 or 2,
The device that operates to enable the expansion of the retard amount is a variable valve device that changes the opening / closing timing of the intake valve or the exhaust valve,
The determination unit determines a diagnosis time based on the presence or absence of an operation command for the variable valve gear.
Diagnostic device.
A method of diagnosing whether or not the operation control of the internal combustion engine for warming up the exhaust purification catalyst is normally executed,
A command to increase the engine speed to warm up the exhaust purification catalyst, or to increase the retard amount when retarding the ignition timing of the engine to warm up the exhaust purification catalyst. A determination step of determining the diagnosis time based on the presence or absence of an operation command of the device to be operated as much as possible;
An execution step of diagnosing whether or not the control for warming up the exhaust purification catalyst is normally executed when it is a diagnosis time;
A diagnostic method comprising: