JP2017145690A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a catalyst from being exposed to a high-temperature exhaust gas.SOLUTION: A control device of an internal combustion engine comprises: a retardation control part which can retard ignition timing by an ignition part; and an increase control part for performing control so as to increase injected fuel when it is determined that an estimation temperature of a catalyst in the case that the ignition timing is retarded exceeds a set temperature. In a combustion chamber in which ignition is performed while a fuel injection part becomes possible to inject an amount of fuel which is controlled so as to be increased from the increase control part, the retardation control part retards the ignition timing by a retardation amount which is smaller than a retardation amount corresponding to a retardation requirement, and in the combustion chamber in which the ignition is performed after the fuel injection part has become possible to inject the amount of fuel which is controlled so as to be increased from the increase control part, the retardation control part retards the ignition timing so as to reach the retardation amount corresponding to the retardation requirement.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for an internal combustion engine.

  Some internal combustion engines are provided with a catalyst for purifying exhaust gas discharged from a combustion chamber. Exhaust gas whose temperature has risen compared to a state in which the ignition timing in the internal combustion engine is not retarded due to retardation may deteriorate the catalyst. The retard of the ignition timing in the internal combustion engine is performed, for example, in an internal combustion engine mounted on a vehicle in order to reduce a shift shock at the time of a shift change.

JP 2009-19521 A

  In the control device for an internal combustion engine disclosed in Patent Document 1, when the ignition timing in the internal combustion engine is retarded, the fuel injected from the fuel injection unit is increased to suppress the temperature rise of the exhaust gas, thereby deteriorating the catalyst. Is preventing. However, in such a control device for an internal combustion engine, since the timing of the start of injection of the increased fuel by the fuel injection unit tends to be delayed with respect to the timing at which the ignition timing in the internal combustion engine is retarded, the fuel injection unit There is a problem that the catalyst may be exposed to high-temperature exhaust gas until the fuel to be injected is increased. Therefore, there has been a demand for a technique that can prevent the catalyst from being deteriorated by preventing the catalyst from being exposed to high-temperature exhaust gas.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  (1) According to one form of this invention, the control apparatus of an internal combustion engine is provided. The control device for an internal combustion engine includes a plurality of combustion chambers having ignition units, a catalyst disposed in an exhaust passage connected to the combustion chambers, and fuel injection for injecting fuel to be supplied to the combustion chambers An internal combustion engine control device comprising: a retard control unit capable of retarding an ignition timing by the ignition unit in response to a retard request; and an estimation of the catalyst when the ignition timing is retarded An increase control unit that controls the fuel injection unit to increase the fuel to be injected when it is determined that the temperature exceeds a set temperature, and the retard control unit is increased from the increase control unit In the combustion chamber that performs ignition until the fuel injection unit can inject the amount of the fuel that is controlled to perform, the retard amount that is smaller than the retard amount corresponding to the retard request And retard the ignition timing, In the combustion chamber that performs ignition after the fuel injection unit can inject the amount of the fuel that is controlled to increase from the increase control unit, the retardation amount corresponding to the retardation request is obtained. The ignition timing is retarded. With this configuration, the retard amount is limited in the combustion chamber that performs ignition until the fuel injection unit can inject the injection amount controlled to increase from the increase control unit. The catalyst can be prevented from being exposed to high-temperature exhaust gas. As a result, deterioration of the catalyst can be prevented. Further, in a vehicle equipped with an internal combustion engine, the ignition timing delay in the internal combustion engine is prevented in order to prevent catalyst deterioration until the fuel injection unit can inject an amount controlled to increase from the increase control unit. Occurrence of deficiencies in drivability caused by delaying the operation can be suppressed.

  (2) In the control device for an internal combustion engine according to the above aspect, the fuel injection unit does not retard the ignition timing by injecting the fuel for a longer time than when the ignition timing is not retarded. More fuel is injected than the case, and the retard control unit performs ignition until the fuel injection unit can inject the amount of fuel controlled to increase from the increase control unit. Among the combustion chambers to be performed, the ignition timing is increased step by step within the range of the retard amount smaller than the retard amount corresponding to the retard request in order from the combustion chamber with the earlier ignition. May be retarded. According to this embodiment, the retard amount can be increased until the fuel injection unit can inject the amount controlled to increase from the increase control unit, as compared with the embodiment in which the retard amount is limited to a constant amount. . As a result, it is possible to further suppress the occurrence of deficiencies in drivability until the fuel injection unit can inject the amount controlled to increase from the increase control unit into the combustion chamber.

  The form of the present invention is not limited to the control device for the internal combustion engine. For example, a vehicle equipped with the control device for the internal combustion engine, a control method for the internal combustion engine, a computer program for realizing the method, and a record for recording the program It can be realized in the form of a medium or the like. Further, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be implemented in various forms without departing from the spirit of the present invention.

It is explanatory drawing which shows the structure of a part of internal combustion engine to which the control apparatus of the internal combustion engine in this embodiment is applied. It is a flow which shows the retard angle control process which the control apparatus of an internal combustion engine performs. In this embodiment, it is explanatory drawing which showed the relationship between the state in each combustion chamber, and exhaust gas temperature. In the reference example, it is explanatory drawing which showed the relationship between the state in each combustion chamber, and exhaust gas temperature. In the reference example, it is explanatory drawing which showed the relationship between the state in each combustion chamber, and exhaust gas temperature. In 2nd Embodiment, it is explanatory drawing which showed the relationship between the state in each combustion chamber, and exhaust gas temperature.

A. First embodiment:
FIG. 1 is an explanatory diagram showing a partial configuration of an internal combustion engine 100 to which an internal combustion engine control apparatus 200 according to this embodiment is applied. The internal combustion engine 100 in this embodiment is a spark ignition type four-stroke cycle gasoline engine using gasoline as fuel, and is mounted on a vehicle. In another embodiment, the internal combustion engine 100 may use any other fuel different from gasoline, and may be mounted not only on the vehicle but also on any other moving body. FIG. 1 schematically shows a cross section of one of the four combustion chambers Ex included in the internal combustion engine 100.

  The internal combustion engine 100 includes a cylinder block 110, a piston 120, a cylinder head 130, an ignition unit 140, an intake valve 150, an intake passage 155, an exhaust valve 160, an exhaust passage 165, a fuel injection unit 170, A catalyst 180.

  The cylinder block 110 has a cylindrical shape with a bottom and accommodates the piston 120. The piston 120 slides in the cylinder block 110 along the axial direction of the cylinder block 110. The cylinder head 130 is disposed at the end of the cylinder block 110.

  A space surrounded by the inner peripheral wall of the cylinder block 110, the piston 120, and the cylinder head 130 functions as a combustion chamber Ex. The ignition unit 140 is disposed in the cylinder head 130 and ignites the air-fuel mixture compressed inside the combustion chamber Ex.

  The intake valve 150 opens and closes between the intake passage 155 communicating with the combustion chamber Ex and the combustion chamber Ex. The intake passage 155 functions as a passage for an air-fuel mixture containing fuel and air, and guides the air-fuel mixture before combustion to the combustion chamber Ex.

  The exhaust valve 160 opens and closes between the exhaust passage 165 communicating with the combustion chamber Ex and the combustion chamber Ex. The exhaust passage 165 functions as a passage for discharging the gas after the air-fuel mixture is combusted from the combustion chamber Ex.

  The fuel injection unit 170 injects fuel to be supplied to the combustion chamber Ex. In the present embodiment, the injection port of the fuel injection unit 170 is disposed inside the intake passage 155 and injects fuel into the intake passage 155. In another embodiment, the injection port of the fuel injection unit 170 may be disposed inside the cylinder block 110 to inject fuel into the cylinder block 110.

  The catalyst 180 purifies the exhaust gas discharged from the combustion chamber Ex. In the present embodiment, the catalyst 180 is a three-way catalyst and simultaneously purifies NOx, CO, and HC in the exhaust gas.

  In the present embodiment, the catalyst 180 is disposed in an exhaust passage in which exhaust passages 165 extending from a plurality of cylinders of the internal combustion engine 100 are gathered. In another embodiment, the catalyst 180 may be disposed in each exhaust passage 165 extending from a plurality of cylinders of the internal combustion engine 100.

  The internal combustion engine control device 200 controls each part in the internal combustion engine 100. The control device 200 for the internal combustion engine includes a retardation control unit 220 and an increase control unit 240. The control device 200 for the internal combustion engine is connected to various sensors (not shown), and acquires various parameters relating to the operating status of the internal combustion engine 100. Examples of the various sensors include a crankshaft sensor, a cam angle sensor, a vehicle speed sensor, an intake pressure sensor, a water temperature sensor, a rotation speed sensor, an accelerator opening sensor, and the like.

  The retard control unit 220 can retard the ignition timing by the ignition unit 140 in response to the retard request. The retard is to delay the ignition timing by the ignition unit 140 from the normal operation of the internal combustion engine 100. In the present embodiment, the retard control unit 220 retards the ignition timing by the ignition unit 140 when a shift change occurs in a vehicle on which the internal combustion engine 100 is mounted. In another embodiment, the retard angle control unit 220 sets the ignition timing by the ignition unit 140 when a so-called knocking occurs in addition to when a shift change occurs in a vehicle on which the internal combustion engine 100 is mounted. You may be retarded.

  When it is determined that the estimated temperature of the catalyst 180 when the ignition timing is retarded exceeds the set temperature, the increase control unit 240 controls the fuel injection unit 170 to increase the fuel to be injected. The estimated temperature of the catalyst 180 is obtained based on the retard amount corresponding to the retard request.

  In the present embodiment, the increase control unit 240 may inject a larger amount of fuel than when the ignition timing is not retarded by injecting fuel for a longer time than when the ignition timing is not retarded. it can.

  The retard angle control unit 220 responds to the retard angle request in the combustion chamber Ex that performs ignition until the fuel injection unit 170 can inject the amount of fuel controlled to increase from the increase control unit 240. The ignition timing is retarded by a retard amount smaller than the retard amount. Further, the retard control unit 220 responds to the request for retard in the combustion chamber Ex that performs ignition after the fuel injection unit 170 can inject the amount of fuel controlled to increase from the increase control unit 240. The ignition timing is retarded so that the retarded amount is reached.

  The retard control unit 220 is set to a constant amount smaller than the retard amount corresponding to the retard request until the fuel injection unit 170 can inject the amount controlled to increase from the increase control unit 240. Limit the amount of retardation. In another embodiment, the retard control unit 220 limits the retard amount to a constant amount until the fuel injection unit can inject 170 the amount controlled to increase from the increase control unit 240. It does not have to be.

  The combustion chamber Ex (hereinafter referred to as Exa) in which ignition is performed before the fuel injection unit 170 can inject the amount of fuel controlled to increase from the increase control unit 240 increases from the increase control unit 240. The combustion chamber Ex (hereinafter referred to as Exb) that performs ignition after the fuel injection unit 170 can inject the amount of fuel controlled to be described will be described.

  Before the ignition with the retarded ignition timing is performed in response to the retardation request, the fuel injection unit 170 injects a larger amount of fuel than when the ignition timing is not retarded, thereby causing the temperature of the exhaust gas. And the deterioration of the catalyst 180 is prevented. In order to inject a larger amount of fuel than when the ignition timing is not retarded, it is necessary to inject fuel for a longer time than when the ignition timing is not retarded.

  Therefore, the timing at which the fuel injection unit 170 starts to inject the increased fuel tends to be delayed with respect to the timing at which the ignition timing in the internal combustion engine 100 is retarded. That is, when the ignition timing is retarded in response to the retardation request, the combustion chamber Ex has a timing sufficient to ensure that the increased amount of fuel injected by the fuel injection unit 170 can be injected before ignition is performed. A combustion chamber Exa that cannot start injection may occur.

  On the other hand, the combustion chamber Exb is a combustion chamber in which injection can be started at a timing at which a time sufficient to inject the increased fuel by the fuel injection unit 170 can be secured before ignition is performed.

  In the present embodiment, when the fuel injection unit 170 cannot start the injection at a timing that can ensure the time sufficient to inject the increased fuel by the fuel injection unit 170 before ignition is performed, the fuel injection unit 170 does not require a delay angle. The amount of fuel in the case shall be injected. In other words, the fuel injection unit 170 does not increase the fuel to be injected until the injection can be started at a timing that can ensure the time sufficient for injecting the increased fuel by the fuel injection unit 170 before ignition is performed.

  FIG. 2 is a flowchart showing a retard angle control process executed by the control device 200 for the internal combustion engine. The control device 200 for the internal combustion engine is periodically executed when a delay angle request is made.

  When the retard control process is started, in step S100, it is determined whether or not the present retard control process is the first time since the last delay request is made (step S100). When it is determined that the present retard control process is the first since the last delay request (S100: YES), the estimated temperature of the catalyst 180 when the ignition timing is retarded is set. It is determined whether or not the temperature is exceeded (step S110).

  When it is determined that the estimated temperature of the catalyst 180 does not exceed the set temperature when the ignition timing is retarded (S110: No), the retard control process of FIG. 2 is terminated. At this time, the retardation control process is not executed until the next retardation request is made. The combustion chamber Ex is retarded in ignition timing by a retard amount corresponding to the retard request.

  When it is determined that the estimated temperature of the catalyst 180 exceeds the set temperature when the ignition timing is retarded (S110: YES), the variable A representing the identification of the combustion chamber Exa and the number of combustion chambers Exa is calculated. (S120). The specification of the combustion chamber Exa here refers to specifying the combustion chamber Exa of the four combustion chambers Ex included in the internal combustion engine 100.

  In step S120, after specifying the combustion chamber Exa and the variable A representing the number of combustion chambers Exa are calculated (step S120), the retard control unit 220 ignites the combustion chamber Exa in the number represented by the variable A. In the combustion chamber Exa with the earliest order, the ignition timing is retarded by a retard amount smaller than the retard amount corresponding to the retard request (step S130).

  After the ignition timing is retarded in the combustion chamber Exa having the earliest ignition order in the combustion chamber Exa (step S130), the variable A is decremented in step S140. (Step S140). After the variable A is decremented (step S140), the retard angle control process is temporarily terminated. At this time, the variable A is saved. The retardation control process is periodically executed until the variable A becomes zero.

  In step S100, when it is determined that the current retard control process is not the first time since the last request for retard (S100: NO), that is, in step S120 in the previous retard control process, When the identification of the combustion chamber Exa and the calculation of the variable A representing the number of combustion chambers Exa have already been performed, in step S130, the retard angle control unit 220 performs ignition in the combustion chamber Exb that is the number represented by the variable A. In the combustion chamber Exa with the earliest order, the ignition timing is retarded by a retard amount smaller than the retard amount corresponding to the retard request (step S130). Thereafter, in step S140, the variable A is decremented (step S140), and the retard angle control process is temporarily terminated. At this time, the variable A is saved. The retardation control process is periodically executed until the variable A becomes zero.

  In step S120 in the first retardation control process after the retardation request is made, the combustion chamber Exa is specified and the variable A representing the number of combustion chambers Exa is calculated. In the second and subsequent retard control processes, the identification of the combustion chamber Exa and the calculation of the variable A representing the number of combustion chambers Exa in step S120 are not performed, and the retard control process is repeated until the variable A becomes zero.

  When the variable A becomes 0, the retardation control process in FIG. 2 is not executed. At this time, the retardation control process is not executed until the next retardation request is made. Then, the combustion chamber Ex that is ignited after the variable A becomes 0 retards the ignition timing by the retard amount corresponding to the retard request as the combustion chamber Exb.

  FIG. 3 shows the internal combustion engine 100 to which the internal combustion engine control apparatus 200 according to the present embodiment is applied. In the internal combustion engine 100, there is a request for retarding the estimated temperature of the catalyst 180 exceeding the set temperature. It is explanatory drawing which showed the relationship between a state and exhaust gas temperature. The four combustion chambers Ex are referred to as Ex1, Ex2, Ex3, and Ex4. The four combustion chambers Ex are ignited in the order of Ex1, Ex3, Ex4, and Ex2. After Ex2 ignites, ignition is performed again in the order of Ex1, Ex3, Ex4, and Ex2.

  3A and 3B, time is taken on the horizontal axis. C0 on the vertical axis in FIG. 3A indicates a state where there is no retardation request, and C1 indicates a state where there is a retardation request. Ex1, Ex3, Ex4, and Ex2 on the vertical axis in FIG. 3B indicate the states in the four combustion chambers Ex.

  A square described as “fuel injection” in FIG. 3B indicates a period during which the fuel injection unit 170 is injecting fuel. A square described as “ignition” in FIG. 3B indicates the timing at which the ignition unit 140 performs ignition.

  In the period RM shown in the upper part of both arrows in FIG. 3 (b), the fuel injection in the case where the ignition timing is retarded by a retard amount smaller than the retard amount corresponding to the retard request is completed. It shows the period from ignition to ignition. The period RL shown in the upper part of the double arrow in FIG. 3B is from the end of fuel injection to the ignition when the ignition timing is retarded by the retard amount corresponding to the retard request. Indicates the period.

  The table on the right side of FIG. 3B shows the state in each combustion chamber Ex. The “retarding angle request” column indicates the degree according to the retardation angle request. The combustion chamber Ex that retarded the ignition timing by the retard amount corresponding to the retard angle request is indicated by ◯, the combustion chamber Ex that is not retarded by the ignition timing is indicated by ×, and from the retard amount corresponding to the retard angle request A combustion chamber Ex in which the ignition timing is retarded by a small retard amount is indicated by Δ.

  The “fuel increase” column indicates the degree of increase in fuel injected from the fuel injection unit 170. A combustion chamber Ex in which the fuel injection unit 170 injects the increased fuel is indicated by ◯, and a combustion chamber Ex in which the fuel injection unit 170 injects fuel when there is no retardation request is indicated by x.

  The column “exhaust gas temperature” indicates the degree of change in the exhaust gas temperature. The combustion chamber Ex in which the exhaust gas temperature has risen is indicated by “rising”, and the combustion chamber Ex in which the exhaust gas temperature has been slightly increased as compared with “rising” is indicated by “slightly rising”, and the rise in the exhaust gas temperature is suppressed The combustion chamber Ex in which the exhaust gas temperature has not changed compared to the combustion chamber Ex in which the ignition timing is not retarded is indicated by “no change”. “Increase suppression” indicates that the increase in the exhaust gas temperature is small compared to “slight increase”, but the increase in the exhaust gas temperature is larger than “no change”. In other embodiments, “rising suppression” may be synonymous with “no change”.

  The description of the notations in FIGS. 3A and 3B is the same for FIGS. 4, 5, and 6. FIG.

  At timing t0 in FIG. 3, C0 in FIG. 3A is switched to C1 due to a request for retardation. At this time, in the control device 200 for the internal combustion engine, the first delay angle control process is started after the delay angle request is made, and the present retard angle control process is the first time after the last delay angle request is made. (Corresponding to step S100 of the present embodiment).

  The current retard angle control process is determined to be the first time since the last delay angle request was made (corresponding to step S100 of this embodiment: “YES”), and then the estimated temperature of the catalyst 180 is set. After determining that the temperature exceeds (step S110 of this embodiment: equivalent to “YES”), a variable A representing the identification of the combustion chamber Exa and the number of combustion chambers Exa is calculated (step S120 of this embodiment). Equivalent). In FIG. 3, combustion chambers Exa, which are combustion chambers in which injection cannot be started at a timing that can ensure sufficient time to inject increased fuel by the fuel injection unit 170 before ignition, are combustion chambers Ex1, Ex3, and Ex4. is there. That is, in FIG. 3, the variable A representing the number of combustion chambers Exa is 3.

  Next, the retard control unit 220 retards the ignition timing with a retard amount smaller than the retard amount corresponding to the retard request in the combustion chamber Ex1 having the earliest ignition order among the three combustion chambers Exa. (Corresponding to step S130 in this embodiment). That is, the period from the end of fuel injection in the combustion chamber Ex1 to the ignition is the period RM.

  After the variable A is decremented (3 → 2) (step S140 in the present embodiment), the retard angle control process is temporarily terminated. At this time, since the retard control process is periodically executed until the variable A becomes 0, the next retard control process is executed.

  In the next retard angle control process, the variable A representing the number of combustion chambers Exa is 2, and the combustion chambers Exa are Ex3 and Ex4. Therefore, the retard angle control unit 220 retards the ignition timing by a retard amount smaller than the retard amount corresponding to the retard request in the combustion chamber Ex3 having the earliest ignition order among the two combustion chambers Exa. (Corresponding to step S130 in this embodiment). That is, the period from the end of fuel injection to the ignition in the combustion chamber Ex3 is the period RM. After the variable A is decremented (2 → 1) (step S140 in the present embodiment), the retard angle control process is temporarily ended. At this time, since the retard control process is periodically executed until the variable A becomes 0, the next retard control process is executed.

  In the next retard control processing, the variable A representing the number of combustion chambers Exa is 1, and the combustion chamber Exa is Ex4. Therefore, the retard control unit 220 retards the ignition timing by a retard amount smaller than the retard amount corresponding to the retard request in the combustion chamber Ex4 (corresponding to step S130 in this embodiment). That is, the period from the end of fuel injection to the ignition in the combustion chamber Ex4 is the period RM.

  In the retard control process at this time, the variable A is decremented (1 → 0) (step S140 in this embodiment), and the variable A becomes 0. Therefore, the retard control process is performed until the next retard request is made. Will no longer be executed. As the combustion chamber Exa, in the combustion chambers Ex1, Ex3, Ex4 in which the ignition timing is retarded by a retard amount smaller than the retard amount corresponding to the retard request, the ignition timing is retarded by the retard amount corresponding to the retard request. Compared to the case where the corner is bent, an increase in the exhaust gas temperature can be suppressed.

  And the combustion chamber Ex ignited after the combustion chamber Ex2 in the ignition sequence retards the ignition timing by the retard amount corresponding to the retard request as the combustion chamber Exb. Therefore, in the combustion chamber Ex that is ignited after the combustion chamber Ex2 in the ignition sequence, the ignition timing is retarded by the retard amount corresponding to the retard request during the period from the end of fuel injection to the ignition. In this case, a period RL from the end of fuel injection to ignition is obtained.

  According to the embodiment described above, the combustion chamber Exa that performs ignition until the fuel injection unit 170 can inject the injection amount controlled to increase from the increase control unit 240 (in the description of FIG. 3, In the combustion chambers Ex1, Ex3, Ex4), the ignition timing is retarded by a retard amount smaller than the retard amount corresponding to the retard request. For this reason, it is possible to prevent the catalyst 180 from being exposed to the high-temperature exhaust gas as compared with the case where the ignition timing is retarded by the retard amount corresponding to the retard request. As a result, deterioration of the catalyst 180 can be prevented.

B. Reference example 1:
FIG. 4 shows a state in each combustion chamber Ex when the internal combustion engine 100 to which the control apparatus 200a for the internal combustion engine in the reference example is applied is requested to be delayed to the extent that the estimated temperature of the catalyst 180 exceeds the set temperature. It is explanatory drawing which showed the relationship between exhaust gas temperature. FIG. 4 shows a case where the combustion chambers Ex1, Ex3, and Ex4 are specified as the combustion chamber Exa after the retardation angle is requested.

  The control device 200a for the internal combustion engine has the same configuration as the control device 200 for the internal combustion engine of the first embodiment, except that it includes a retard angle control unit 220a different from the retard angle control unit 220. The retard angle control unit 220a retards the ignition timing so that the retard amount corresponding to the retard angle request is obtained in both the combustion chamber Exa and the combustion chamber Exb.

  In the control device 200a for the internal combustion engine, the ignition timing is retarded by the retard amount corresponding to the retard request in the combustion chamber Exa (Ex1, Ex3, Ex4), so that the catalyst 180 is exposed to high-temperature exhaust gas. Will be. As a result, the catalyst 180 is likely to be deteriorated.

C. Reference example 2:
FIG. 5 shows a state in each combustion chamber Ex when an internal combustion engine 100 to which the control apparatus 200b of the internal combustion engine in the reference example is applied is requested to be retarded so that the estimated temperature of the catalyst 180 exceeds the set temperature. It is explanatory drawing which showed the relationship between exhaust gas temperature. FIG. 5 shows a case where the combustion chambers Ex1, Ex3, and Ex4 are specified as the combustion chamber Exa after the delay angle request is made. In FIG. 5, a period RS shown at the top of the double arrow indicates a period from when the fuel injection is finished to when the ignition is performed when the retard request is not satisfied.

  The internal combustion engine control device 200b has the same configuration as the internal combustion engine control device 200 of the first embodiment, except that the internal combustion engine control device 200b includes a retardation control unit 220b different from the retardation control unit 220. The retard control unit 220b retards the ignition timing in the combustion chamber Ex until the fuel injection unit 170 can inject the amount controlled to increase from the increase control unit 240 in order to prevent the catalyst 180 from deteriorating. Delay. That is, the ignition timing in the combustion chamber Exa is not retarded. The retard control unit 220b controls the combustion chamber Exb in the same manner as the retard control unit 220.

  In the control device 200b for the internal combustion engine, the ignition timing is not retarded in the combustion chamber Exa (Ex1, Ex3, Ex4), and therefore the temperature of the exhaust gas does not change even when there is a retard angle request. However, by not retarding the ignition timing, there is a high possibility that a deficiency in drivability will occur in a vehicle equipped with an internal combustion engine.

  In contrast to the reference example 2, in the first embodiment, in the vehicle in which the internal combustion engine 100 is mounted, in order to prevent the catalyst 180 from deteriorating, the fuel injection unit 170 supplies the amount controlled to increase from the increase control unit 240. It is possible to suppress deficiencies in drivability caused by delaying the retard of the ignition timing in the internal combustion engine until the fuel can be injected. A deficiency in drivability is, for example, a so-called engine speed increase that occurs during a shift change.

  In contrast to the reference example 1 and the reference example 2, the first embodiment can prevent the catalyst 180 from being deteriorated and can suppress the occurrence of problems in drivability in a vehicle or the like in which the internal combustion engine 100 is mounted.

D. Second embodiment:
FIG. 6 shows an internal combustion engine 100 to which the internal combustion engine control apparatus 200c according to the second embodiment is applied. It is explanatory drawing which showed the relationship between this state and exhaust gas temperature. FIG. 6 shows a case where the combustion chambers Ex1, Ex3, and Ex4 are specified as the combustion chamber Exa after the retardation angle is requested.

  The control device 200c for the internal combustion engine has the same configuration as the control device 200 for the internal combustion engine of the first embodiment, except that a retard angle control unit 220c different from the retard angle control unit 220 is provided. The retardation control unit 220c increases the retardation amount stepwise within the range of the retardation amount smaller than the retardation amount corresponding to the retardation request, in order from the combustion chamber Exa with early ignition in the combustion chamber Exa. Delay the ignition timing.

  That is, in FIG. 6, the ignition timing is increased stepwise in the order of the combustion chamber Ex1, the combustion chamber Ex3, and the combustion chamber Ex4 within the range of the retard amount smaller than the retard amount corresponding to the retard request. Retard.

  The periods Rm1, Rm2, and Rm3 shown in the upper part of both arrows in FIG. 6B are obtained when the ignition timing is retarded within a retard amount that is smaller than the retard amount corresponding to the retard request. The period from the end of fuel injection to the ignition is shown. The period Rm1 is shorter than the period Rm2 and the period Rm3. The period Rm2 is shorter than the period Rm3.

  According to the second mode, the amount of delay is retarded as compared with the mode in which the amount of retard is limited to a constant amount until the fuel injection unit 170 can inject the amount controlled to increase from the increase control unit 240. The amount can be increased. As a result, it is possible to further suppress the occurrence of deficiencies in drivability until the fuel injection unit 170 can inject the amount controlled to increase from the increase control unit 240 into the combustion chamber.

E. Variations:
In the control apparatus 200 for the internal combustion engine in the first embodiment and the control apparatus 200c for the internal combustion engine in the first embodiment, a time sufficient to inject the increased fuel by the fuel injection unit 170 can be ensured before ignition is performed. When the injection cannot be started at the timing, the fuel injection unit 170 injects the amount of fuel when there is no retardation request, but the present invention is not limited to this. For example, the fuel injection unit 170 can inject fuel before ignition is performed even when the fuel injection unit 170 cannot start injection at a timing that can ensure sufficient time to inject the increased fuel before ignition is performed. The fuel may be injected for the time. According to such a form, it is possible to realize at a higher level that the occurrence of problems in drivability is suppressed and that the catalyst is prevented from being exposed to high-temperature exhaust gas.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above-described effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 110 ... Cylinder block 120 ... Piston 130 ... Cylinder head 140 ... Ignition part 150 ... Intake valve 155 ... Intake passage 160 ... Exhaust valve 165 ... Exhaust passage 170 ... Fuel injection part 180 ... Catalyst 200 ... Control apparatus 200a ... Control Device 200b ... Control device 220 ... Delay control unit 220a ... Delay control unit 220b ... Delay control unit 240 ... Increase control unit

Claims (2)

An internal combustion engine comprising: a plurality of combustion chambers having ignition units; a catalyst disposed in an exhaust passage connected to the combustion chambers; and a fuel injection unit that injects fuel to be supplied to the combustion chambers. A control device,
A retard control unit capable of retarding the ignition timing by the ignition unit in response to a retard request;
An increase control unit that controls the fuel injection unit to increase the fuel to be injected when it is determined that the estimated temperature of the catalyst when the ignition timing is retarded exceeds a set temperature; ,
In the combustion chamber that performs ignition until the fuel injection unit can inject the amount of the fuel that is controlled to increase from the increase control unit, the retardation control unit The fuel injection unit can inject the amount of the fuel controlled to increase from the increase control unit while retarding the ignition timing by the retard amount smaller than the retard amount corresponding to A control apparatus for an internal combustion engine, wherein the ignition timing is retarded so that the retard amount corresponding to the retard request is obtained in the combustion chamber that performs ignition from the start. The control device according to claim 1,
The fuel injection unit injects the fuel for a longer time than when the ignition timing is not retarded, thereby injecting a larger amount of the fuel than when the ignition timing is not retarded,
The retard angle control unit is configured to quickly ignite among the combustion chambers that perform ignition until the fuel injection unit can inject the amount of the fuel controlled to increase from the increase control unit. A control device for an internal combustion engine that retards the ignition timing by increasing the retard amount in a stepwise manner within a range of the retard amount that is smaller than the retard amount corresponding to the retard request in order from the combustion chamber.

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