JP6545038B2 - Ignition timing control device - Google Patents

Description

  The present invention relates to an ignition timing control device, and more particularly to an ignition timing control device that calculates the ignition timing of an internal combustion engine mounted on a vehicle and limits the correction amount to the retard side in the ignition timing.

  In recent years, in vehicles such as motorcycles, ignition of an engine is realized from the viewpoint of realizing high output, low fuel consumption and exhaust gas purification while ensuring the reliability of the engine that is an internal combustion engine mounted thereon. An ignition timing control device that electronically controls the timing is employed.

  The ignition timing of the engine is controlled by the ignition timing control device to appropriately change from the compression top dead center to the advancing side or the retarding side, in consideration of various conditions related to the engine. In order to achieve a smooth output characteristic of the engine that would cause the engine to burn properly while ensuring the reliability of the engine, and for the driver not to feel uncomfortable, more precise control of the ignition timing is required. ing.

  Under such circumstances, Patent Document 1 relates to an ignition timing control device for acceleration, and controls the ignition timing of the engine so as not to exceed the retard side limit value to the retard side based on the throttle opening degree and the change amount thereof. Is disclosed. Specifically, the configuration of Patent Document 1 suppresses the excessive retardation of the ignition timing of the engine in an operating state in which the engine load transiently increases despite the fact that the engine speed does not increase so much, and the combustion It is intended to stabilize and prevent a decrease in engine output.

Japanese Patent Application Laid-Open No. 11-343953

  Here, the ignition timing of the engine can be calculated by correcting the basic ignition timing with various correction amounts. The various correction amounts include an environmental correction amount and a driving state correction amount. The environmental correction amount reflects the environmental condition of the engine such as the coolant temperature of the engine. For example, the engine is knocked by correcting the ignition timing to the retard side under the environmental condition where the engine is high temperature and knocking is likely to occur. To protect from The operating state correction amount reflects the operating state of the engine, such as the amount of change in the throttle opening. For example, retarding the ignition timing when the throttle opening suddenly changes suppresses the output of the engine and its fluctuation. The purpose is to

  However, according to the further study of the present inventor, the operating state correction is performed when the retardation correction is limited as in the configuration of Patent Document 1 with respect to the ignition timing of the engine that is retarded by various correction amounts. By offsetting the amount of retardation correction and the restriction of retardation correction, for example, an event occurs that can not be sufficiently suppressed although it is preferable to originally suppress the engine output and its fluctuation It is conceivable.

  The present invention has been made through the above study. For example, when the engine is at a high temperature, the engine output can be corrected by excessively retarding the ignition timing while protecting the engine from knocking. An object of the present invention is to provide an ignition timing control device capable of allowing an ignition timing retardation correction to be performed when it is preferable to suppress an unnecessary decrease and, for example, to suppress the output of the engine and its fluctuation.

In order to achieve the above object, the present invention provides a basic ignition timing of an internal combustion engine mounted on a vehicle, an environmental correction amount reflecting the environmental state of the internal combustion engine, and an operating state correction reflecting the operating state of the internal combustion engine In the ignition timing control device provided with an ignition timing control unit that calculates the ignition timing of the internal combustion engine based on the amount, the ignition timing control unit is configured to set the first basic ignition timing and the second basic ignition timing as the basic ignition timing. The environment including at least one of the first basic ignition timing, a cooling water temperature correction amount calculated based on the cooling water temperature of the internal combustion engine, and an intake air temperature correction amount calculated based on the intake air temperature of the internal combustion engine a correction amount, and the operation state correction amount, and calculates the first ignition timing on the basis of, not based on the environmental correction amount, and the timing the second basic ignition, and the driving state correction quantity Calculating a second ignition timing based on, when a predetermined switching condition is satisfied, the switching to the second ignition timing the ignition timing from the first ignition timing in the first aspect.

  Further, in the present invention, in addition to the first aspect, in the predetermined switching condition, the sum of the first basic ignition timing and the environmental correction amount is on the retarded side with respect to the second basic ignition timing. The second phase is to be set to the condition that

  Further, according to the present invention, in addition to the first or second aspect, in the third aspect, the ignition timing control unit calculates the second basic ignition timing in accordance with a load state of the internal combustion engine. .

According to the ignition timing control device according to the first aspect of the present invention described above, the ignition timing control unit uses the first basic ignition timing and the second basic ignition timing as the basic ignition timing, and the first basic ignition timing, Based on an environmental correction amount including at least one of a cooling water temperature correction amount calculated based on a cooling water temperature of the internal combustion engine and an intake air temperature correction amount calculated based on an intake air temperature of the internal combustion engine When the first ignition timing is calculated, the second ignition timing is calculated based on the second basic ignition timing and the operating state correction amount not based on the environmental correction amount, and a predetermined switching condition is satisfied In this case, the ignition timing is switched from the first ignition timing to the second ignition timing. Therefore, for example, when the engine is at a high temperature, the environmental correction amount is increased to the retard side while protecting the engine from knocking. Due to In addition to suppressing an unnecessary decrease in the output of the engine due to excessive retardation correction at the fire timing, for example, when it is preferable to suppress the output of the engine and its fluctuation, the operating state correction amount is on the retard side Thus, it is possible to control the ignition timing to an appropriate value while allowing the ignition timing to be retarded due to the increase to the above.

  Further, according to the ignition timing control device according to the second aspect of the present invention, the predetermined switching condition is such that the sum of the first basic ignition timing and the environmental correction amount is more retarded than the second basic ignition timing. Therefore, the ignition timing can be properly and reliably switched to the second ignition timing in which the retardation correction amount to the retardation side from the first ignition timing is limited. .

  Further, according to the ignition timing control device according to the third aspect of the present invention, since the ignition timing control unit calculates the second basic ignition timing according to the load state of the internal combustion engine, the second basic ignition is The timing can be calculated more appropriately according to the load condition of the internal combustion engine.

FIG. 1 is a block diagram showing the configuration of an ignition timing control apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing a flow of ignition timing control processing executed by the ignition timing control device in the present embodiment.

Hereinafter, an ignition timing control apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
[Configuration of Ignition Timing Control Device]
First, the configuration of the ignition timing control device according to the present embodiment will be described in detail with reference to FIG.

  FIG. 1 is a block diagram showing a configuration of an ignition timing control device in the present embodiment.

  As shown in FIG. 1, the ignition timing control device 1 in this embodiment is an arithmetic processing device such as a microcomputer mounted on a vehicle (not shown) and having a CPU (Central Processing Unit), a memory, etc. Is the ECU (Electronic Control Unit). The ignition timing control device 1 reads out the necessary control program and control data from the memory, and limits the amount of retard correction to the retard side of the ignition timing of the engine, which is an internal combustion engine mounted on the vehicle, as necessary. While, the control program for the ignition timing control process etc. which controls the ignition timing is executed.

  The ignition timing control device 1 includes input circuits 2a, 2b, 2c, 2d and 2e, A / D converters 3a, 3b, 3d and 3e, a waveform shaping circuit 3c, a ROM 4 (Read Only Memory), and a RAM (Random Access Memory). 5, a CPU 6 and an ignition circuit 7 are provided.

  The input circuit 2a acquires an output signal of the water temperature sensor 11a that detects the temperature (cooling water temperature) of engine cooling water, and inputs the acquired output signal to the A / D converter 3a.

  The input circuit 2b acquires an output signal of the intake air temperature sensor 11b that detects the temperature (intake air temperature) of intake air of the engine, and inputs the acquired output signal to the A / D converter 3b.

  The input circuit 2c acquires an output signal of the crank sensor 11c that detects a crank angle of the engine (rotational angle of the crankshaft), and inputs the acquired output signal to the waveform shaping circuit 3c.

  The input circuit 2d acquires an output signal of the throttle sensor 11d for detecting the opening degree (throttle opening degree) of a throttle valve (not shown), and inputs the obtained output signal to the A / D converter 3d. Do.

  The input circuit 2e acquires the output signal of the vehicle speed sensor 11e that detects the speed (vehicle speed) of the vehicle, and inputs the acquired output signal to the A / D converter 3e.

  The A / D converters 3a, 3b, 3d and 3e convert the electric signals in analog form input from the corresponding input circuits 2a, 2b, 2d and 2e into electric signals in digital form, and output them to the CPU 6.

  The waveform shaping circuit 3 c shapes the waveform of the electrical signal in analog form input from the input circuit 2 c and outputs the shaped signal to the CPU 6.

  The ROM 4 is configured of a non-volatile storage device, and stores control programs and control data for an ignition timing control process described later.

  The RAM 5 is configured of a volatile storage device and functions as a working area for storing the calculated value of the CPU 6 and the like.

  The CPU 6 controls the overall operation of the ignition timing control device 1. In the present embodiment, the CPU 6 functions as an ignition control unit 6a, an engine rotation number calculation unit 6b, and a throttle opening degree calculation unit 6c by reading and executing a control program stored in the ROM 4. The ignition control unit 6a includes a first basic ignition timing calculation unit 6a1, an environmental correction amount calculation unit 6a2, an operating condition correction amount calculation unit 6a3, and a second basic ignition timing calculation unit 6a4. In addition, although these are comprised as a functional block of CPU6, you may be comprised as an electric circuit outside CPU6.

  Specifically, the ignition control unit 6a determines whether a predetermined ignition timing switching condition is satisfied. As a result of the discrimination, if the predetermined ignition timing switching condition is not satisfied, it is preferable to not limit the correction of the ignition timing to protect the engine from knocking. The unit 6a sets the ignition timing of the engine to a first ignition timing whose retardation correction amount is not limited. On the other hand, when a predetermined ignition timing switching condition is established, it is preferable to protect the engine from knocking while limiting the correction of the retardation of the ignition timing to suppress an unnecessary decrease in the engine output. In order to correspond to the situation, the ignition control unit 6a advances the ignition timing relative to the first ignition timing so as to limit the retardation correction amount so that the retardation correction of the ignition timing of the engine is not excessively performed. It sets to the 2nd ignition timing which exhibits the value (angle) of the side.

  Here, as shown in the equation (Equation 1), typically, the first ignition timing IGF (deg) includes the first basic ignition timing IGRF (deg), the environmental correction amount IGID (deg), and the operating state It is the sum of the correction amount IGES (deg). Further, as shown in the equation (Equation 2), the second ignition timing IGS (deg) is typically the sum of the second basic ignition timing IGRS (deg) and the operating state correction amount IGES (deg). .

  Specifically, as shown in the equation (Equation 3), the environmental correction amount IGID (deg) is typically a cooling water temperature correction amount IGW (based on the engine cooling water temperature and the intake air temperature). It is the sum of the deg) and the intake air temperature correction amount IGT (deg). The environmental correction amount IGID is, for example, a correction amount that retards the ignition timing in order to protect the engine from knocking when the engine has a high temperature, and it is preferable to limit the retardation correction amount of the engine ignition timing. In this case, the correction amount is offset by the limitation of the retardation correction amount.

  Further, as shown in the equation (Equation 4), the operating state correction amount IGES (deg) is typically calculated based on the amount of change in the throttle opening (the acceleration state of the engine) and the vehicle speed. It is the sum of the acceleration correction amount IGA (deg) and the vehicle speed correction amount IGV (deg). The operating state correction amount IGES is, for example, a correction amount for adjusting the ignition timing in order to optimize the operating state of the engine by suppressing the output of the engine or its fluctuation, and also retarding the ignition timing of the engine. Even when it is preferable to limit the correction amount, the correction amount is not offset by the limitation of the retardation correction amount.

Further, as shown in the equation (Equation 5), the predetermined ignition timing switching condition is typically that the sum of the first basic ignition timing IGRF and the environmental correction amount IGID is greater than or equal to the second basic ignition timing IGRS. It is a condition that the inequality that the angle (the angle equal to or more advanced than the second basic ignition timing IGRS) does not hold.

  The first basic ignition timing calculation unit 6a1 calculates a first basic ignition timing IGRF based on the engine rotation speed calculated by the engine rotation speed calculation unit 6b and the throttle opening calculated by the throttle opening calculation unit 6c. The first basic ignition timing IGRF is a value (angle) of the basic ignition timing according to the load state of the engine.

  The environmental correction amount calculator 6a2 calculates the cooling water temperature correction amount IGW based on the electric signals input from the A / D converters 3a and 3b, respectively, based on the cooling water temperature and the intake air temperature. The environmental correction amount IGID is calculated by calculating the sum of the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT while calculating the intake air temperature correction amount IGT. Note that the environmental correction amount calculation unit 6a2 applies one of the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT as the environmental correction amount IGID according to the necessity of simplification of the configuration, etc. Well, in such a case, correspondingly, one of the cooling water temperature and the intake air temperature will be used.

  The driving state correction amount calculation unit 6a3 calculates the acceleration correction amount based on the electric signals input from the A / D converters 3d and 3e respectively on the basis of the change amount of the throttle opening and the vehicle speed. The driving state correction amount IGES is calculated by calculating the sum of the acceleration correction amount IGA and the vehicle speed correction amount IGV while calculating the IGA and the vehicle speed correction amount IGV. The driving state correction amount calculation unit 6a3 may apply one of the acceleration correction amount IGA and the vehicle speed correction amount IGV as the driving state correction amount IGES according to the necessity of simplification of the configuration, etc. In such a case, one of the throttle opening change amount and the vehicle speed is used correspondingly.

  The second basic ignition timing calculation unit 6a4 calculates a second basic ignition timing IGRS based on the engine rotation speed calculated by the engine rotation speed calculation unit 6b and the throttle opening calculated by the throttle opening calculation unit 6c. The second basic ignition timing IGRS is a value (angle) of the basic ignition timing according to the load condition of the engine, but the first basic ignition timing IGRF calculated by the first basic ignition timing calculation unit 6a1 and the environmental correction amount It includes a value (angle) more advanced than the sum of the environmental correction amount IGID calculated by the calculation unit 6a2.

  The engine rotation number calculation unit 6b calculates an engine rotation number based on the electric signal input from the waveform shaping circuit 3c. The engine rotation speed calculated by the engine rotation speed calculation unit 6 b is used by the first basic ignition timing calculation unit 6 a 1 and the second basic ignition timing calculation unit 6 a 4.

  The throttle opening degree calculator 6c calculates the throttle opening degree based on the electrical signal input from the A / D converter 3d. The throttle opening degree calculated by the throttle opening degree calculation unit 6c is used by the first basic ignition timing calculation unit 6a1 and the second basic ignition timing calculation unit 6a4.

  The ignition circuit 7 generates a secondary voltage in the ignition coil 12 in accordance with a control signal from the CPU 6.

The ignition timing control device 1 having such a configuration performs an ignition timing control process described below to suppress excessive retardation correction to the ignition timing when the engine temperature is high, etc. Control the ignition timing to an appropriate value. Hereinafter, the flow of the ignition timing control process performed by the ignition timing control device 1 according to the present embodiment will be described with further reference to FIG.
[Ignition timing control processing]
FIG. 2 is a flowchart showing a flow of ignition timing control processing executed by the ignition timing control device in the present embodiment.

  As shown in the flowchart of FIG. 2, the ignition timing control process in the present embodiment starts at the timing when the vehicle is activated and the ignition timing control device 1 operates, and the ignition timing control process proceeds to step S1. The ignition timing control process is repeatedly performed while the vehicle is activated and the ignition timing control device 1 is in operation.

  In the process of step S1, the engine speed and engine speed calculating unit 6b and the throttle opening degree calculating unit 6c respectively correspond to the electric signal input from the waveform shaping circuit 3c and the A / D converter 3d. Calculate the throttle opening. Then, the first basic ignition timing calculation unit 6a1 reads out the first basic ignition timing calculation data stored in the ROM 4 and applies the engine speed and the throttle opening degree to the first basic ignition timing calculation data and refers to this Thus, the first basic ignition timing IGRF of the engine corresponding to the engine speed and the throttle opening degree is calculated. The first basic ignition timing IGRF is a value of the basic ignition timing according to the load condition of the engine. Also, the first basic ignition timing calculation data may be given by a calculation formula other than the form of the table or the map. Thus, the process of step S1 is completed, and the ignition timing control process proceeds to the process of step S2.

  In the process of step S2, the environment correction amount calculation unit 6a2 is based on the electric signals input from the A / D converters 3a and 3b respectively, that is, based on the cooling water temperature and the intake air temperature. While calculating the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT, and calculating the sum of the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT, the environmental correction amount IGID is calculated. In the calculation of the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT, the environmental correction amount calculation unit 6a2 reads the respective calculation data stored in the ROM 4, and corresponds the cooling water temperature and the intake air temperature to the calculation data. Application and reference is made to these. The environment correction amount calculation unit 6a2 may apply one of the cooling water temperature correction amount IGW and the intake air temperature correction amount IGT as the environment correction amount IGID as necessary, and in such a case, Then, one of the cooling water temperature and the intake air temperature will be used. Further, each calculation data may be given by a calculation formula other than the form of the table or the map. Thus, the process of step S2 is completed, and the ignition timing control process proceeds to the process of step S3.

  In the process of step S3, the driving state correction amount calculation unit 6a3 is based on the electric signals input from the A / D converters 3d and 3e respectively, that is, corresponding to the change amount of the throttle opening and the vehicle speed. The driving state correction amount IGES is calculated by calculating the acceleration correction amount IGA and the vehicle speed correction amount IGV and calculating the sum of the acceleration correction amount IGA and the vehicle speed correction amount IGV. In the calculation of the acceleration correction amount IGA and the vehicle speed correction amount IGV, the driving state correction amount calculation unit 6a3 reads the respective calculation data stored in the ROM 4, and the calculation data changes the throttle opening degree and the vehicle speed Is applied correspondingly and referring to these. Note that the driving state correction amount calculation unit 6a3 may apply one of the acceleration correction amount IGA and the vehicle speed correction amount IGV as the driving state correction amount IGES as necessary, and in such a case, Correspondingly, one of the throttle opening change amount and the vehicle speed is used. Further, each calculation data may be given by a calculation formula other than the form of the table or the map. Thus, the process of step S3 is completed, and the ignition timing control process proceeds to the process of step S4.

  In the process of step S4, the second basic ignition timing calculation unit 6a4 reads the second basic ignition timing calculation data stored in the ROM 4 and calculates the engine rotation speed calculated by the process of step S1 as the second basic ignition timing calculation data. The second basic ignition timing IGRS of the engine corresponding to the engine rotational speed and the throttle opening degree is calculated by applying and referring to the number and the throttle opening degree. The second basic ignition timing IGRS is a value of the basic ignition timing according to the load condition of the engine, but is more than the sum of the first basic ignition timing IGRF and the environmental correction amount IGID calculated in the process of step S3. It contains the value on the advance side. Further, the second basic ignition timing calculation data may be given by a calculation formula in addition to the form of the table or the map. Thus, the process of step S4 is completed, and the ignition timing control process proceeds to the process of step S5.

  In the process of step S5, the ignition control unit 6a determines whether a predetermined ignition timing switching condition is satisfied, that is, the sum of the first basic ignition timing IGRF and the environmental correction amount IGID is greater than or equal to the second basic ignition timing IGRS. It is determined whether it is a value (advance side value). As a result of the determination, if the sum of the first basic ignition timing IGRF and the environmental correction amount IGID is equal to or greater than the second basic ignition timing IGRS (advance (advance) side), the ignition timing switching condition is satisfied in this case. Since the case does not exist, the ignition control unit 6a advances the ignition timing control process to the process of step S6. On the other hand, when the sum of the first basic ignition timing IGRF and the environmental correction amount IGID is less than the second basic ignition timing IGRS (retard side), the ignition timing switching condition is satisfied in this case. Since this is the case, the ignition control unit 6a advances the ignition timing control process to the process of step S7.

  In the process of step S6, the ignition control unit 6a calculates the sum of the first basic ignition timing IGRF, the environmental correction amount IGID, and the operating state correction amount IGES (first ignition timing) to set the ignition timing of the engine to the first In addition to setting the ignition timing IGF, a control signal for causing the ignition coil 12 to generate a secondary voltage is output to the ignition circuit 7. Thus, the process of step S6 is completed, and the current series of ignition timing control processes end.

  In the process of step S7, the ignition control unit 6a calculates the sum (second ignition timing) of the second basic ignition timing IGRS and the operating state correction amount IGES, and sets the ignition timing of the engine to the second ignition timing IGS. At the same time, a control signal for causing the ignition coil 12 to generate a secondary voltage is output to the ignition circuit 7 accordingly. Thereby, the process of step S7 is completed and a series of ignition timing control processes are complete | finished.

  As apparent from the above description, in the ignition timing control device 1 according to this embodiment, the ignition control unit 6a uses the first basic ignition timing IGRF and the second basic ignition timing IGRS as the basic ignition timing, and performs the first basic ignition. The first ignition timing IGF is calculated based on the timing IGRF, the environmental correction amount IGID, and the operating state correction amount IGES, and the second ignition timing IGS is calculated based on the second basic ignition timing IGRS and the operating state correction amount IGES. When the predetermined switching condition is satisfied, the ignition timing is switched from the first ignition timing IGF to the second ignition timing IGS, and the second ignition timing is compared with the retardation correction amount of the first ignition timing IGF to the retardation side. Since the retardation correction amount to the retard side of the ignition timing IGS is limited, by switching the ignition timing to the second ignition timing IGS, for example, when the engine is at high temperature, the engine While preventing the engine output from being unnecessarily reduced due to excessive retardation correction to the ignition timing due to the environmental correction amount IGID increasing to the retard side while protecting against knocking, for example, In the case where it is preferable to suppress the output of the engine and its fluctuation, the ignition timing is made appropriate by allowing the ignition timing to be retarded due to the operating state correction amount IGES increasing to the retard side. Can be controlled to any value.

  Further, in the ignition timing control device 1 according to the present embodiment, the condition that the predetermined switching condition is such that the sum of the first basic ignition timing IGRF and the environmental correction amount IGID is more retarded than the second basic ignition timing IGRS. Since the ignition timing is set to 1, it is possible to more appropriately switch the ignition timing from the first ignition timing IGF to the second ignition timing IGS in which the retardation correction amount to the retardation side is restricted.

  Further, in the ignition timing control device 1 according to the present embodiment, the ignition control unit 6a calculates the second basic ignition timing IGRS according to the load state of the engine, so the second basic ignition timing IGRS corresponds to the load state of the engine Can be calculated more appropriately.

  In the present invention, the type, shape, arrangement, number, and the like of members are not limited to those in the above-described embodiment, and the components of the present invention can be appropriately replaced by those having equivalent effects. Of course, changes can be made as appropriate without departing from the scope of the invention.

  As described above, the present invention provides an ignition timing control device capable of controlling the ignition timing to an appropriate value by suppressing excessive retardation correction to the ignition timing when the engine temperature is high. It is expected that it can be widely applied to the ignition timing control apparatus of vehicles, such as a two-wheeled motor vehicle, from the universal character of the universality.

DESCRIPTION OF SYMBOLS 1 ... Ignition timing control apparatus 2a, 2b, 2c, 2d and 2e ... Input circuit 3a, 3b, 3d and 3e ... A / D converter 3c ... Waveform shaping circuit 4 ... ROM
5 ... RAM
6 ... CPU
6a ... ignition control unit 6a1 ... first basic ignition timing calculation unit 6a2 ... environment correction amount calculation unit 6a3 ... operating state correction amount calculation unit 6a4 ... second basic ignition timing calculation unit 6b ... engine rotation speed calculation unit 6c ... throttle opening degree Calculation unit 7: Ignition circuit 11a: Water temperature sensor 11b: Intake air temperature sensor 11c: Crank sensor 11d: Throttle sensor 11e: Vehicle speed sensor 12: Ignition coil

Claims (3)

The ignition timing of the internal combustion engine is calculated based on the basic ignition timing of the internal combustion engine mounted on the vehicle, the environmental correction amount reflecting the environmental state of the internal combustion engine, and the operating state correction amount reflecting the operating state of the internal combustion engine. An ignition timing control device including an ignition timing control unit that
The ignition timing control unit uses a first basic ignition timing and a second basic ignition timing as the basic ignition timing, and calculates a cooling water temperature correction amount calculated based on the first basic ignition timing and the cooling water temperature of the internal combustion engine. And calculating the first ignition timing based on the environmental correction amount including at least one of the intake air temperature correction amount calculated based on the intake air temperature of the internal combustion engine and the operating state correction amount, and the environmental correction not based on the amount and the second basic ignition timing, the operating condition correction amount, the second calculates the ignition timing based on, when a predetermined switching condition is satisfied, the said ignition timing first An ignition timing control device characterized by switching from 1 ignition timing to the second ignition timing.   The predetermined switching condition is set such that the sum of the first basic ignition timing and the environmental correction amount is on the retarded side with respect to the second basic ignition timing. The ignition timing control device according to claim 1.   The ignition timing control device according to claim 1 or 2, wherein the ignition timing control unit calculates the second basic ignition timing according to a load state of the internal combustion engine.

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