Ignition device for internal combustion engines and control device for vehicles

Abstract

Ignition device for an internal combustion engine (100) in a vehicle (900) driven by combining the internal combustion engine (100) and an electric motor (600), comprising an ignition control unit (83) that discharges a spark plug (200) after the vehicle (900) is driven by the electric motor (600) before starting operation of the internal combustion engine (100); a temperature measuring device (122) which measures a water temperature of the internal combustion engine (100) or an outside air temperature, wherein the ignition control unit (83) discharges the spark plug (200) before starting the operation of the internal combustion engine (100) while the vehicle (900) is operated by the electric motor (600), and comprises a switching control unit (2) configured to switch from operation by the electric motor (600) to operation by the internal combustion engine (100) when the water temperature of the internal combustion engine (100) or outside air temperature measured by the temperature measuring device (122) is greater than or equal to a predetermined threshold temperature.

Description

Technical FieldThe present invention relates to an ignition device for an internal combustion engine and a control device for a vehicle.Prior ArtFor some years, in internal combustion engines, there has been a demand for improved performance of exhaust catalysts (three-way catalysts) as the exhaust guidelines become more and more stringent. For exhaust catalysts for internal combustion engines, expensive noble metals such as platinum are used. However, as the exhaust regulations become more and more stringent, many noble metals must be used to improve the exhaust gas purification performance, and thus the production cost of exhaust catalysts increases.In this type of engine, a large amount of hydrocarbons (hydrocarbon: HC) is generated at the time of cold start where the temperature of the engine is lower than the outside air temperature. Thus, by preventing generation of hydrocarbons at the time of cold start, the amount of used noble metal in the exhaust catalyst can be reduced and the production cost of the exhaust catalyst can be lowered.In the internal combustion engine, however, control is performed to increase the fuel injection amount at the time of cold start to prevent misfire of an ignition device (spark plug) at the time of cold start. Thus, the amount of hydrocarbons generated at the time of cold start increases, and lowering of the cost of the exhaust catalyst is made difficult.PTL 1 discloses an engine ignition device that prevents a decrease in temperature of the ignition device by performing ignition of the ignition device at a timing (exhaust timing) other than a normal ignition timing in a combustion cycle of the internal combustion engine.PTL 2 relates to a method of vaporizing moisture on a spark plug of an internal combustion engine in which, when the water temperature at the last engine stop is less than 60° C., at engine start is less than 20° C., and the intake air temperature is less than 10° C., fuel supply to a combustion chamber is stopped for about one second after the start switch is turned on.PTL 3 relates to a method for operating a spark plug of an ignition system in an internal combustion engine by means of a frequency generator for exciting the spark plug, the spark plug having two electrodes which extend into a combustion chamber and between which a dielectric is partially located, wherein a plasma discharge is periodically ignited between the electrodes, waste heat is released in the period between two excitations of the plasma discharge in the dielectric, and in this way the parts of the spark plug which extend into the combustion chamber are heated.List of InstructionsPatent LiteraturePTL 1: JP 6 220 677 APTL 2: JP H05-33 698 APTL 3, German Patent Document DE 10 2006 037 246 A1SUMMARY OF THE INVENTIONTechnical TaskHowever, in the ignition device of the engine as disclosed in PTL 1, after the temperature of the spark plug of the internal combustion engine rises, lowering of the temperature of the spark plug is prevented, and a temperature rise is performed on the ignition device before the cold start of the internal combustion engine is started. Thus, generation of hydrocarbons at the time of cold start of the internal combustion engine cannot be prevented, and the production cost of the exhaust catalyst can be hardly lowered.Accordingly, the invention has been developed in view of the foregoing problems, and an object thereof is to prevent generation of hydrocarbons at the time of cold start of an internal combustion engine and reduce the production cost of an exhaust catalyst.Technical SolutionThe above object is achieved by the subject matter of claim 1. Preferred developments are described in the dependent claims.Advantageous Effects of the InventionAccording to this invention, generation of hydrocarbons at the time of cold start of the internal combustion engine can be prevented, and production cost of an exhaust catalyst can be lowered.Brief Description of the Drawings[FIG. 1 ] FIG. 1 is a diagram for describing a configuration of main parts of an internal combustion engine and a control device of the internal combustion engine according to an embodiment.[FIG. 2 ] FIG. 2 is a partially enlarged view for describing a spark plug.[FIG. 3] FIG. 3 is a functional block diagram illustrating a functional configuration of the control device.[FIG. 4] FIG. 4 is a diagram for describing a relationship among an electrode temperature, a dielectric breakdown voltage, and an air-fuel ratio.[FIG. 5 ] FIG. 5 shows an example of a timing chart for illustrating an output timing of an ignition signal according to the embodiment.[FIG. 6 ] FIG. 6 shows an example of a flowchart illustrating a method of controlling an ignition device by an ignition control unit.[FIG. 7 ] FIG. 7 shows an example of a timing chart for illustrating an output timing of an ignition signal according to a second embodiment.[FIG. 8] FIG. 8 is a circuit diagram for describing an example of a circuit of an ignition device for an internal combustion engine according to a third embodiment.[FIG. 9 ] FIG. 9 shows an example of a pre-ignition signal output from an ignition control unit according to a third embodiment.[FIG. 10 ] FIG. 10 is a diagram for describing a cycle of discharge generated in an ignition coil according to the third embodiment.[FIG. 11 ] FIG. 11 is a diagram for describing a waveform of a pre-ignition signal and an electrode temperature of a spark plug according to the third embodiment.[FIG. 12] FIG. 12 is a diagram for describing an ignition device for an internal combustion engine according to a fourth embodiment.[FIG. 13 ] FIG. 13 is a diagram for describing an ignition device for an internal combustion engine according to a fifth embodiment.[FIG. 14] FIG. 14 is a diagram for describing an ignition device for an internal combustion engine according to a sixth embodiment.[FIG. 15] FIG. 15 is a diagram for describing ignition of a spark plug.DESCRIPTION OF EMBODIMENTSAn ignition device for an internal combustion engine and a method for controlling the ignition device according to the embodiment of the invention will be described below.Next, a control device 1 for an internal combustion engine according to an embodiment of the invention will be described. In the embodiment, a case where the control device 1 controls discharge (ignition) of a spark plug 200 disposed in each cylinder 150 of a four-cylinder internal combustion engine 100 is described.Hereinafter, in the embodiment, a combination of some or all of the configurations of the internal combustion engine 100 or some or all of the configurations of the control device 1 refers to the control device 1 of the internal combustion engine 100.[Internal Combustion Engine]FIG. 1 is a diagram showing the configuration of main parts of the internal combustion engine 100 and the ignition device for an internal combustion engine.FIG. 2 is a partially enlarged view showing electrodes 210 and 220 of the spark plug 200.In the internal combustion engine 100, air sucked from the outside passes through an air cleaner 110, an intake pipe 111, and an intake manifold 112 and flows into each cylinder 150. The amount of air flowing into each cylinder 150 is controlled by a throttle valve 113, and the amount of air controlled by the throttle valve 113 is measured by a flow sensor 114.The throttle valve 113 is provided with a throttle opening sensor 113a for detecting the opening of the throttle, and the opening information of the throttle valve 113 detected by the throttle opening sensor 113a is outputted to the control device (electronic control unit) 1.An electronic throttle valve driven by an electric motor is used as the throttle valve 113. However, any other types may be used as long as the amount of air flow can be controlled accordingly.The temperature of the gas flowing into each cylinder 150 is detected by an intake air temperature sensor 115.A crank angle sensor 121 is disposed on the outer side in the radial direction of a ring gear 120 fixed to a crankshaft 123, and the crank angle sensor 121 detects a rotation angle of the crankshaft 123. In the embodiment, the crank angle sensor 121 detects the rotation angle of the crankshaft 123 every 10° and every combustion cycle.A water temperature sensor 122 is disposed in a water pocket (not shown) of the cylinder head, and the water temperature sensor 122 detects the temperature of the cooling water of the internal combustion engine 100.In addition, a vehicle is also equipped with an accelerator position sensor 126 that detects the amount of movement (amount of stepping) of an accelerator pedal 125. The accelerator pedal position sensor 126 detects a torque requested by a driver. The driver required torque detected by the accelerator position sensor 126 is output to the control device 1 described below. The control device 1 controls the throttle valve 113 based on this requested torque.The fuel stored in a fuel tank 130 is sucked and pressurized by a fuel pump 131, then passes through a fuel line 133 equipped with a pressure regulator 132, and is supplied to a fuel injection valve 134 (injection nozzle). The fuel discharged from the fuel pump 131 is regulated to a predetermined pressure by the pressure regulator 132, and injected into each cylinder 150 by the fuel injection valve 134 (injection nozzle). Due to the pressure regulation by the pressure regulator 132, excess fuel is directed back into the fuel tank 130 via a return line (not shown).A cylinder head (not shown) of the internal combustion engine 100 is equipped with an internal combustion pressure sensor 140 (also referred to as a cylinder pressure sensor or an in-cylinder pressure sensor). The combustion pressure sensor 140 is disposed in each cylinder 150, and detects the pressure (combustion pressure) in the cylinder 150.The combustion pressure sensor 140 is a piezoelectric sensor or a positive pressure sensor, and is configured to detect the combustion pressure (in-cylinder pressure) in the cylinder 150 over a wide temperature range.Each cylinder 150 is provided with an exhaust manifold 160 that conveys post-combustion gases (exhaust gases) from the cylinder 150 to the outside. A three-way catalyst 161 is disposed on the exhaust side of the exhaust manifold 160, and the exhaust gases are purified by the three-way catalyst 161 and then discharged to the atmosphere.An upstream air-fuel ratio sensor 162 is disposed at an upstream side of the three-way catalyst 161. The upstream air-fuel ratio sensor 162 continuously detects the air-fuel ratio of the exhaust gases discharged from each cylinder 150.A downstream air-fuel ratio sensor 163 is disposed at a downstream side of the three-way catalyst 161. The downstream air-fuel ratio sensor 163 outputs a switch-like detection signal in the vicinity of the theoretical air-fuel mixture. In the embodiment, the downstream air-fuel ratio sensor 163 is an O 2- sensor.In addition, the spark plug 200 is disposed at the upper portion of each cylinder 150, and a spark ignites an air-fuel mixture in the cylinder 150 by discharging (igniting) the spark plug 200. An explosion occurs in cylinder 150 and a piston 170 is forced downwardly. When the piston 170 is pushed down, the crankshaft 123 rotates.An ignition coil 300 that generates a voltage supplied to the ignition plug 200 is connected to the ignition plug 200, and the voltage generated by the ignition coil 300 causes discharge between a center electrode 210 and an outer electrode 220 of the ignition plug 200 (see FIG. 2 ).As illustrated in FIG. 2, in the spark plug 200, the center electrode 210 is held in an insulated state by an insulator 230, and a predetermined voltage (20,000 V to 40,000 V in the embodiment) is applied to the center electrode 210.The outer electrode 220 is grounded, and when a predetermined voltage is applied to the center electrode 210, discharge (ignition) occurs between the center electrode 210 and the outer electrode 220.Further, in the spark plug 200, a voltage at which discharge (ignition) occurs varies due to the dielectric breakdown of the gas component according to the state of the gas between the center electrode 210 and the outer electrode 220 and the in-cylinder pressure. The voltage at which this discharge occurs is referred to as the dielectric breakdown voltage.The discharge control of the spark plug 200 is performed by an ignition control unit 83 of the control device 1 as described below.It is understood from FIG. 1 that signals outputted from various sensors such as the throttle opening sensor 113 a, the flow sensor 114, the crank angle sensor 121, the accelerator position sensor 126, the water temperature sensor 122, and the combustion pressure sensor 140 as described above are outputted to the control device 1. The control device 1 detects the operation state of the internal combustion engine 100 on the basis of the signals output from these various sensors, and controls the amount of air flowing into the cylinder 150, a fuel injection amount, and an ignition timing of the spark plug 200.[Hardware Configuration of Control Device]Next, the hardware configuration of the control device 1 as a whole will be described.As illustrated in FIG. 1, the control device 1 includes an analog input unit 10, a digital input unit 20, an A / D (analog / digital) converter 30, a RAM (random access memory) 40, and an MPU (micro processing unit) 50, a ROM (read only memory) 60, an I / O (input / output) port 70, and an output circuit 80.The analog input unit 10 includes analog output signals from various kinds of sensors such as the throttle opening sensor 113 a, the flow sensor 114, the accelerator position sensor 126, the upstream air-fuel ratio sensor 162, the downstream air-fuel ratio sensor 163, the combustion pressure sensor 140, and the water temperature sensor 122.The A / D converter 30 is connected to the analog input unit 10. The analog output signals from various sensors input to the analog input unit 10 are subjected to signal processing such as denoising, and converted into digital signals by the A / D converter 30, and stored in the RAM 40.The digital output signal from the crank angle sensor 121 is output to the digital input unit 20.The I / O port 70 is connected to the digital input unit 20, and the digital output signal input to the digital input unit 20 is stored in the RAM 40 via the I / O port 70.Each output signal stored in the RAM 40 is processed by the MPU 50.The MPU 50 executes a control program (not shown) stored in the ROM 60, whereby the output signal stored in the RAM 40 is calculated according to the control program. The MPU 50 calculates a control value defining the operation amount of each actuator (for example, the throttle valve 113, the pressure regulator 132, the spark plug 200, etc.) that drives the internal combustion engine 100 according to the control program, and temporarily stores the control value in the RAM 40.The control value defining the actuator operation amount stored in the RAM 40 is output to the output circuit 80 via the I / O port 70.The output circuit 80 is provided with a function of an ignition control unit 83 (see FIG. 3 ) that controls a voltage applied to the spark plug 200.[Functional Block of Control Device]Next, the functional configuration of the control device 1 will be described.FIG. 3 is a functional block diagram showing the functional configuration of the control device 1. each function of the control device 1 is performed by the output circuit 80 through the MPU 50 executing the control program stored in the ROM 60.As illustrated in FIG. 3, the output circuit 80 of the control device 1 includes an overall control unit 81, a fuel injection control unit 82, and the ignition control unit 83.The overall control unit 81 is connected to the accelerator pedal position sensor 126 and the combustion pressure sensor 140, and receives a requested torque (acceleration signal S 1) from the accelerator pedal position sensor 126 and the output signal S 2 from the combustion pressure sensor 140.The overall control unit 81 performs overall control of the fuel injection control unit 82 and the ignition control unit 83 on the basis of the requested torque (acceleration signal S 1) from the accelerator position sensor 126 and the output signal S 2 from the combustion pressure sensor 140.The fuel injection control unit 82 is connected to a cylinder discrimination unit 84 that discriminates each cylinder 150 of the internal combustion engine 100, an angle information generation unit 85 that measures the crank angle of the crankshaft 123, and a rotational speed information generation unit 86 that measures the engine rotational speed, and receives a cylinder discrimination information S 3 from the cylinder discrimination unit 84, a crank angle information S 4 from the angle information generation unit 85, and an engine rotational speed information S 5 from the rotational speed information generation unit 86.Further, the fuel injection control unit 82 is connected to an intake air amount measurement unit 87 that measures the amount of air sucked into the cylinder 150, a load information generation unit 88 that measures the engine load, and a water temperature measurement unit 89 that measures the temperature of an engine coolant, and receives intake air amount information S 6 from the intake air amount measurement unit 87, engine load information S 7 from the load information generation unit 88, and coolant temperature information S 8 from the water temperature measurement unit 89.The fuel injection control unit 82 calculates the fuel injection amount injected from the fuel injection valve 134 and the injection timing (fuel injection valve control information S9) based on the received information, and controls the fuel injection valve 134 based on the calculated fuel injection amount and the calculated injection timing.In addition to the overall control unit 81, the ignition control unit 83 is connected to and receives information from the cylinder discrimination unit 84, the angle information generation unit 85, the rotational speed information generation unit 86, the load information generation unit 88, and the water temperature measurement unit 89.Based on the received information, the ignition control unit 83 calculates the amount of current (energization angle) for energizing a primary coil 310 of the ignition coil 300, an energization timing, and a timing (ignition timing) for cutting off the current for energizing the primary coil 310.The ignition control unit 83 controls the discharge by the ignition plug 200 by outputting an ignition signal S to the primary coil 310 of the ignition coil 300 on the basis of the calculated energization amount, the energization start timing, and the ignition timing.Further, at least the spark plug 200, the ignition coil 300 and the ignition control unit 83 are included as described above, and the function of controlling the ignition of the spark plug 200 by the ignition control unit 83 corresponds to an ignition device for an internal combustion engine of the invention.At the time of cold start of the internal combustion engine 100, the air-fuel ratio required for ignition (the more fuel needs to be concentrated) is necessarily lower than the temperature of the electrode of the spark plug 200 is lower.FIG. 4 is a graph for describing a relationship among an electrode temperature, a dielectric breakdown voltage, and an air-fuel ratio.As shown in FIG. 4, in the internal combustion engine 100, when the air-fuel ratio (the thinner the fuel) becomes large, it is difficult to ignite the air-fuel mixture by discharging (igniting). Therefore, the dielectric breakdown voltage for igniting the air-fuel mixture needs to be increased.When the dielectric breakdown voltage is constant (the output current of the ignition coil 300 is constant), the breakdown voltage cannot be exceeded unless the air-fuel ratio is lowered (the fuel is concentrated) when the temperature of the electrode of the ignition coil 200 decreases. Thus, in the internal combustion engine 100, generation of hydrocarbons (HC) during combustion increases as the proportion of fuel in the air-fuel mixture increases.That is, as the temperature of the electrode of the spark plug 200 increases at the start of the cold start operation (see a thick arrow in FIG. 4 ), the dielectric breakdown voltage may be exceeded even when the air-fuel ratio becomes larger (the fuel is decreased), and the hydrocarbons during combustion may be decreased. Therefore, in the internal combustion engine 100, the temperature of the electrode of the spark plug 200 at the time of cold start before discharge (ignition) increases, so that the air-fuel ratio at the time of cold start can be increased and generation of hydrocarbons (HC) can be prevented.In the example illustrated in FIG. 4, when the electrode temperature of the spark plug 200 is low, the air-fuel ratio for ignition is P 1 at a predetermined dielectric breakdown voltage. When the electrode temperature is high, the air-fuel ratio for ignition becomes at a predetermined dielectric breakdown voltage P 2. Therefore, as the electrode temperature increases, the fuel required for ignition may be decreased and the amount of hydrocarbons (HC) generated by combustion decreases.[Method of Heating Spark Plug]Next, a method of heating the electrodes of the spark plug 200 by the ignition control unit 83 according to the embodiment will be described.FIG. 5 shows an example of a timing chart showing the output timing of the ignition signal S output from the ignition control unit 83.In FIG. 5, the top row represents an ON / OFF signal of an ignition switch SW of a vehicle (not shown). The ignition switch SW is turned on by inserting a key (not shown) into and turning it (or by operating a start key in a keyless device).The second row from the top represents the output signal of the crank angle sensor 121. After the ignition switch SW is turned on and the crank angle sensor 121 starts to detect the rotation of the crankshaft 123 with the start of the movement of the internal combustion engine 100, the output of the crankshaft sensor 121 is turned on.The third row from the top represents the ignition signal S output from the ignition control unit 83 to the ignition coil 300. The ignition signal S comprises a pre-ignition signal Sp and an ignition signal Sa output after the pre-ignition signal Sp. The pre-ignition signal Sp represents pre-ignition performed before discharge (ignition) for burning (ignition of the air-fuel mixture) in the combustion stroke to increase the temperature of the spark plug 200 before cold start (hereinafter referred to as pre-discharge). The ignition signal Sa is an ignition signal executed for combustion (ignition of the air-fuel mixture) in the combustion stroke.In the embodiment, the ignition control unit 83 outputs an ignition signal Sa for generating a discharge (ignition) in the spark plug 200 in a combustion stroke in a combustion cycle and a pre-ignition signal Sp for generating a discharge (ignition) in the spark plug 200 to the ignition coil 300.As shown in FIG. 5, the pre-ignition signal Sp includes a plurality of times of outputs generated after the time T 1 when the ignition switch SW is turned on, before the time T 2 when the signal is output from the crank angle sensor 121, and before the time T 3 when the fuel injection is performed from the fuel injection valve 134. That is, the pre-ignition signal Sp is output a plurality of times before the first explosion in each cylinder 150.Here, the first explosion means the first combustion (explosion) in the first combustion stroke of each cylinder 150 after the operation of the internal combustion engine 100 starts. That is, in the internal combustion engine 100, after the start of the operation, the first explosion occurs only once in each cylinder 150, and then a predetermined combustion cycle (intake stroke→compression stroke→combustion stroke→inclampion stroke) is repeated.The pre-ignition signal Sp is a signal that causes a smaller voltage change in the ignition coil 300 than the ignition signal Sa for combustion (ignition of the air-fuel mixture), and is generated in the ignition coil 300 by the pre-ignition signal Sp. The voltage is set lower than the dielectric breakdown voltage.The ignition control unit 83 outputs the pre-ignition signal Sp a plurality of times so that a discharge is generated in the ignition coil 200 based on the pre-ignition signal Sp, and the discharge of the ignition coil 200 causes the ignition coil 200 (center electrode 210 and outer electrode 220) to be heated (hereinafter referred to as pre-ignition).Thus, in the spark plug 200 according to the embodiment, the electrode of the spark plug 200 is heated (preheated) by the plurality of pre-discharges before the first explosion until the discharge (ignition) of the spark plug 200 in the combustion stroke. As a result, as described above, even if the air-fuel ratio is increased (the fuel is decreased) at the time of discharge (ignition) of the ignition coil 200 in the combustion stroke, generation of hydrocarbons (HC) due to the combustion at the time of cold start can be prevented.The fourth row from the top represents the ON / OFF signal of fuel injector 134. When the fuel injection valve 134 is operated, a predetermined amount of fuel is injected from the fuel injection valve 134 into the cylinder 150 (combustion chamber). Subsequently, based on the ignition signal Sa for combustion output from the ignition control unit 83, the air-fuel mixture in the cylinder 150 (combustion chamber) burns, and the pressure in the cylinder 150 rises steeply.The lower row represents the in-cylinder pressure in the cylinder 150 (combustion chamber). The in-cylinder pressure is measured by the combustion pressure sensor 140, and the measurement result of the combustion pressure sensor 140 is output. As described above, in the internal combustion engine 100, after a predetermined amount of fuel is injected from the fuel injection valve 134 to generate an air-fuel mixture in the combustion chamber, the air-fuel mixture is ignited at the timing (timing T 4) when the ignition signal Sa is turned off to generate combustion. The combustion pressure sensor 140 measures the in-cylinder pressure in the combustion cycle.[Control Method of Ignition Device]An example of a method of controlling the ignition device by the ignition control unit 83 will be described below.FIG. 6 is an example of a flowchart showing a method of controlling the ignition device by an ignition control unit 83.As shown in FIG. 6, in step S 101, the ignition control unit 83 determines whether the ignition switch SW is ON. When it is determined that the ignition switch SW is ON (step S 101: YES), the process proceeds to step S 102. When it is determined that the ignition switch is not ON (OFF) (step S 101: NO), the process ends.In step S 102, when the ignition control unit 83 determines whether the output value of the crank angle sensor is OFF and the output value is OFF (step S 102: YES), the process proceeds to step S 103. When it is determined that the output is not OFF (ON) (step S 102: NO), it is determined that the cylinder 150 is not in the first explosion, and the process ends.In step S 103, the ignition control unit 83 determines whether the fuel injection valve 134 is OFF. When it is determined that the fuel injection valve 134 is OFF (step S 103: YES), the process proceeds to step S 104. When it is determined that the fuel injection valve is not OFF (ON) (step S 103: NO), the process ends.In step S 104, the ignition control unit 83 outputs the pre-ignition signal Sp to the ignition coil 300 a plurality of times, and the process proceeds to process S 105.In step S 105, the ignition control unit 83 determines whether the number of pulses of the pre-ignition signal Sp is equal to or larger than a predetermined threshold Nth. When it is determined that the number of pulses of the pre-ignition signal Sp is equal to or larger than the threshold Nth (step S 105: YES), it is determined that the spark plug 200 has been heated to the predetermined temperature, and the process ends. When the ignition control unit 83 determines that the number of pulses of the pre-ignition signal SP is less than the threshold Nth (step S 105: NO), the process returns to step S 101 and repeats the processes from steps S 101 to S 105.As described above, in the embodiment, the ignition control unit 83 is provided to control the discharge of the spark plug 200 disposed in the cylinder 150. In the first combustion cycle after the operation of the internal combustion engine 100 is started, the ignition control unit 83 performs discharging of the spark plug 200 in a state where fuel in the cylinder 150 is not injected from the fuel injection valve 134 into the cylinder 150.With this configuration, by discharging the spark plug 200 before the fuel injection in the first combustion cycle after the operation of the internal combustion engine 100 is started, the spark plug 200 can be overheated, so that hydrocarbon (HC) at the time of cold start can be prevented.In addition, in the first combustion cycle, after the operation of the internal combustion engine 100 is started, the ignition control unit 83 performs discharging of the spark plug 200 a plurality of times in a state in which fuel is not injected from the fuel injection valve 134 into the cylinder 150.With this configuration, the spark plug 200 can be discharged a plurality of times before the fuel injection in the first combustion cycle after the operation of the internal combustion engine 100 is started, so that the spark plug 200 can be reliably overheated. Generation of hydrocarbons (HC) at the time of cold start can be reliably prevented.[Second Embodiment]Next, a control device for an internal combustion engine according to a second embodiment will be described.In the above-described embodiment, the case where the ignition control unit 83 outputs the pre-ignition signal Sp after the ignition switch SW is operated by the driver has been described as an example. However, before the ignition switch SW is operated, the operation of the vehicle may be detected in advance in the near future, and the pre-ignition signal Sp may be output at an earlier time based on the detection.FIG. 7 shows an example of a timing chart for describing the output timing of the ignition signal according to the second embodiment.As illustrated in FIG. 7, the ignition control unit 83 predicts the start (movement) of the vehicle and outputs the pre-ignition signal Sp a plurality of times at the predicted time T 1.Prediction of the start (driving) of the vehicle by the ignition control unit 83 can be performed by operating the brake pedal of the vehicle, opening and closing the door of the vehicle, shutting off the door, seating on the driver's seat, a load on the steering wheel, presence / absence (posture) of the driver detected by an in-vehicle camera mounted in the vehicle, a position of a smartphone in possession of the driver, and a posture of the key. By acquiring these pieces of information, the ignition control unit 83 can predict that the driver will drive with the vehicle in the near future.Accordingly, the ignition control unit 83 outputs and executes the pre-ignition signal Sp a plurality of times at time T 1 before time T 2 when the ignition switch SW is operated, thereby performing the execution and completion of the heating of the ignition plug 200 at an earlier stage. Therefore, even if the driver immediately starts the vehicle, the spark plug 200 may already be sufficiently heated at time T 3 when the ignition switch SW is operated and the accelerator pedal is depressed. The amount of hydrocarbon (HC) generated at the time of a cold start may be significantly reduced.As described above, in the second embodiment, the spark plug 200 may be heated (pre-warming) before the operation of the internal combustion engine 100 is started (before the cold start), and the air-fuel ratio at the time of combustion after the operation is started may be decreased. Therefore, generation of hydrocarbons (HC) at the start of operation (at the time of cold start) can be prevented.With this configuration, the spark plug 200 is discharged a plurality of times before the operation of the internal combustion engine 100 is started, so that the spark plug 200 can be overheated before the operation is started. Generation of hydrocarbons (HC) at the time of cold start can be reliably prevented.[Third Embodiment]Next, an ignition device for an internal combustion engine according to a third embodiment will be described.The ignition device for an internal combustion engine according to the third embodiment differs from the above-described embodiment in that the waveform of the pre-ignition signal Sp can be adjusted.FIG. 8 is a circuit diagram for describing an example of a circuit 500 of the ignition device for an internal combustion engine according to the third embodiment.FIG. 9 shows an example of the pre-ignition signal Sp output from the ignition control unit 83 according to the third embodiment.FIG. 10 is a diagram for describing a cycle of discharge generated in the ignition coil 200 according to the third embodiment.FIG. 11 is a diagram for describing the waveform of the pre-ignition signal Sa and the electrode temperature of the spark plug 200 according to the third embodiment.As shown in FIG. 8, the ignition coil 300 is disposed in the circuit 500, which includes the primary coil 310 wound with a predetermined number of turns and a secondary coil 320 wound with a larger number of turns than the primary coil 310.One end of the primary coil 310 is connected to a DC power source 330. Thus, a predetermined voltage (12 V in the embodiment) is applied to the primary coil 310.The other end of the primary coil 310 is connected to the drain (D) terminal of a firing electrode 340, and is grounded via the source (S) terminal of the firing electrode 340. In the embodiment, a field effect transistor (FET) or the like is used as the ignition electrode 340.The gate (G) terminal of the ignition electrode 340 is connected to the ignition control unit 83, and the ignition signal S output from the ignition control unit 83 is input to the gate (G) terminal of the ignition electrode 340.When the ignition signal S is input to the gate (G) terminal of the ignition electrode 340, the drain (D) terminal and the source (S) terminal of the ignition electrode 340 turn into the excitation state, and current flows between the drain (D) terminal and the source (S) terminal. With this configuration, current (energy) is stored in the primary coil 310.When the output of the ignition signal S from the ignition control unit 83 is stopped and the current flowing through the primary coil 310 is cut off, a high voltage corresponding to the coil winding ratio is generated in the secondary coil 320. When the high voltage generated in the secondary coil 320 is applied to the spark plug 200 (the center electrode 210), a discharge is generated between the center electrode 210 and the outer electrode 220 of the spark plug 200. When a discharge voltage generated between the center electrode 210 and the outer electrode 220 becomes equal to or higher than the dielectric breakdown voltage of the gas (air-fuel mixture in the cylinder 150), the gas component undergoes dielectric breakdown and is ignited.Here, the circuit 500 includes a primary current control circuit 560, and the primary current control circuit 560 includes a resistor R 1 and a semiconductor element 550.In the primary current control circuit 560, the resistor R 1 is disposed in series with the gate (G) terminal of the ignition electrode 340, and the semiconductor element 550 is disposed in parallel with the resistor R 1.As the semiconductor element 550, a field effect transistor (FET) similar to the ignition electrode 340 may be used. The semiconductor element 550 includes a drain (D) terminal, a gate (G) terminal, and a source (S) terminal. The gate (G) terminal is connected to the ignition control unit 83, and the waveform adjustment flag F is input from the ignition control unit 83.This waveform adjustment flag F is a signal that turns off or on the ignition control unit 83 on the basis of the temperature of the internal combustion engine 100 itself, the cooling water temperature, and the outside air temperature. In the embodiment, the ignition control unit 83 normally turns on the waveform adjustment flag F. When the temperature of the internal combustion engine 100, the cooling water temperature, and the outside air temperature are detected to be lower than a predetermined threshold temperature Tth, the waveform adjustment flag F is set to OFF.In the semiconductor element 550, the drain (D) terminal and the source (S) terminal change to the non-excitation state in a state where the waveform adjustment flag F is not input to the gate (G) terminal. When the waveform adjustment flag (F) is applied to the gate (G) terminal, the drain (D) terminal and the source (S) terminal are changed to the excitation state.When the drain (D) terminal and the source (S) terminal of the semiconductor element 550 are changed to the non-excitation state, the ignition signal S output from the ignition control unit 83 passes through the resistor R 1 and is input to the gate (G) of the ignition electrode 340. In turn, when the drain (D) terminal of the source (S) terminal of the semiconductor element 550 is in the excitation state, the ignition signal S output from the ignition control unit 83 passes between the drain (D) terminal and the source (S) terminal of the semiconductor element 550 and is input to the gate (G) terminal of the ignition electrode 340.In the embodiment, when it is determined that the temperature of the internal combustion engine 100 is higher than the predetermined threshold temperature Tth, the ignition control unit 83 outputs the ignition signal S and the waveform adjustment flag F, and the drain (D) terminal and the source (S) terminal of the ignition electrode 340 change to the energization state. Thus, in the ignition coil 300, the current Ip flows through the primary coil 310, and during this time, current (energy) is stored in the primary coil 310.In this state, the ignition signal S passes through the drain (D) terminal and the source (S) terminal of the semiconductor element 550, and is input to the gate (G) terminal of the ignition electrode 340.On the other hand, when it is determined that the temperature of the engine 100 is lower than the predetermined threshold temperature Tth, the ignition control unit 83 turns off the waveform adjustment flag F.Subsequently, the drain (D) terminal and the source (S) terminal of the semiconductor element 550 are changed to the non-excitation state, and the ignition signal S output from the ignition control unit 83 passes through the resistor R 1 and is input to the gate (G) terminal of the ignition electrode 340.Here, in the ignition electrode 340, as the resistance value connected to the gate (G) terminal increases, the fall time of the ignition signal S becomes longer due to the switching operation characteristic of the field effect transistor.Thus, in the ignition electrode 340, when the temperature or the like of the internal combustion engine 100 is higher than the threshold temperature Tth and the waveform adjustment flag F is turned on, the ignition signal S output from the ignition control unit 83 passes through the drain (D) terminal and the source (S) terminal of the semiconductor element 550. Therefore, the resistance connected to the gate (G) terminal of the ignition electrode 340 when the ignition signal S passes is small, and the falling waveform of the ignition signal S becomes a waveform whose falling time shown in the left drawing of FIG. 9 is short.In turn, in the ignition electrode 340, when the temperature or the like of the internal combustion engine 100 is lower than the threshold temperature Tth and the waveform adjustment flag F is turned off, the ignition signal S output from the ignition control unit 83 passes through the resistor R1. Therefore, the resistance connected to the gate (G) terminal of the ignition electrode 340 when passing the ignition signal S is large, and the falling waveform of the ignition signal S is a smooth waveform having a long falling time as illustrated in the right drawing of FIG. 9.Thus, in the ignition coil 300, the rate of change (decrease rate) of the current Ip flowing through the primary coil 310 decreases, so that the voltage Vs of the secondary coil 320 generated according to the decrease rate decreases and one cycle (frequency) becomes longer.Therefore, as illustrated in FIG. 10, when the temperature or the like of the internal combustion engine 100 is lower than the threshold temperature Tth, the voltage Vs of the ignition coil 300 (the secondary coil 320) is set to a somewhat long cycle, so that the discharge generated in the spark plug 200 becomes a somewhat long cycle (solid line in FIG. 10 : see long discharge specification). In turn, when the temperature or the like of the internal combustion engine 100 is higher than the threshold temperature Tth, the voltage Vs of the ignition coil 300 (the secondary coil 320) is set to a substantially short cycle, so that the discharge (ignition) generated in the spark plug 200 becomes a substantially short cycle (broken line in FIG. 10 : see short discharge specification).Further, the energy (the area of the solid waveform in FIG. 10 ) when the discharge voltage is discharged in a slightly long cycle and the energy (the area of the dotted waveform in FIG. 10 when the discharge voltage is discharged in a substantially short cycle have the same area and the required energy is the same.Thus, as illustrated in FIG. 10, in the spark plug 200, when the discharge is performed in a long cycle, the energization time (heating time) of the electrodes ( 210, 220) is longer than when the discharge is performed in a short cycle. The temperature rise of the electrode increases. That is, in the spark plug 200, when the discharge is performed in a long cycle, the cooling time during which the electrode is not heated is shortened, and the electrode is rapidly heated in a short time.As described above, in the third embodiment, the ignition control unit 83 is configured to control at least the discharge frequency and voltage of the spark plug 200.With this configuration, the discharge frequency and voltage of the spark plug 200 can be changed, and the spark plug 200 can be efficiently heated.In addition, the ignition control unit 83 is configured to control the discharge frequency and voltage of the spark plug 200 based on the water temperature of the internal combustion engine 100 or the outside air temperature.With this configuration, the discharge frequency and voltage of the spark plug 200 can be changed according to the water temperature or outside temperature of the internal combustion engine 100 (the spark plug 200), and the spark plug 200 can be efficiently heated.[Fourth Embodiment]Next, an ignition device for an internal combustion engine according to a fourth embodiment will be described.FIG. 12 is a diagram for describing an engine ignition device according to the fourth embodiment.In the fourth embodiment, an example in which the engine ignition device is used in a hybrid vehicle using two power sources in the form of an engine 100 and an electric motor (hereinafter referred to as a hybrid electric vehicle (HEV) motor) is described.As illustrated in FIG. 12, in the hybrid vehicle 900, in a period from the time T 1 when the ignition switch SW is turned on to the time T 2 when the heating of the ignition plug 200 is completed by the pre-ignition signal Sa (at least before fuel is injected from the fuel injection valve 134), the vehicle runs with only the HEV engine (not illustrated).With this configuration, generation of a large amount of hydrocarbons (HC) due to the combustion before completion of heating of the spark plug 200 can be reliably prevented, and the drivability of the driver is not impaired.That is, in the hybrid vehicle, after the time T 1 at which the ignition switch SW is turned on, the vehicle runs with the HEV engine at least during the time T 2 at which fuel is injected from the fuel injection valve 134 and while the spark plug 200 is heated with a pre-discharge. With this configuration, in the internal combustion engine 100, the combustion in the first combustion cycle is performed after the internal combustion engine 100 is warmed up, so that the amount of generated hydrocarbons (HC) can be reliably reduced.This type of hybrid vehicle (not shown) is equipped with a large-capacity battery (not shown). Therefore, by using the ignition device for an internal combustion engine of the invention in a hybrid vehicle, even when the pre-discharge is performed at the time of cold start of the internal combustion engine 100, the consumption amount with respect to the battery capacity is small. Therefore, there is no fear of insufficient battery capacity due to the pre-discharge.As described above, in the fourth embodiment, in the hybrid vehicle (900 (vehicle) driven with the combination of the engine 100 and the HEV motor 600 (electric motor), the ignition control unit 83 causes the HEV motor 600 to drive the hybrid vehicle 900 before the operation of the engine 100 starts, and then the spark plug 200 is discharged.With such a configuration, the HEV engine 600 runs before the spark plug 200 is heated, and during this time, the spark plug 200 may be sufficiently heated. Therefore, the spark plug 200 can be reliably overheated before the start of the operation of the internal combustion engine 100 without impairing the drivability of the driver, so that the generation of hydrocarbons (HC) at the start of the operation of the internal combustion engine 100 can be reliably prevented.[Fifth Embodiment]Next, an ignition device for an internal combustion engine according to a fifth embodiment will be described.FIG. 13 is a diagram for describing an engine ignition device according to the fifth embodiment.As illustrated in FIG. 13, the hybrid vehicle 900 includes two power sources in the form of the engine 100 and the HEV motor 600, and the control device 1 controls any one of the power sources for driving the hybrid vehicle 900.The ignition device for an internal combustion engine according to the fifth embodiment includes a shift control unit 2. the shift control unit 2 selects whether to operate the vehicle 900 with the HEV engine 600 or the internal combustion engine 100 on the basis of temperature information such as the temperature of the internal combustion engine 100 itself, the cooling water temperature, and the outside air temperature.When it is determined that the engine 100 has been sufficiently warmed by the pre-warming in the engine ignition device and the temperature of the engine 100 has exceeded a predetermined threshold temperature Tth, the switching control unit 2 outputs a switching signal G for switching from the operation by the HEV motor 600 to the operation by the engine 100 to the control device 1.The control device 1 switches the power source to be controlled from the HEV motor 600 to the engine 100 on the basis of the switching signal G transmitted from the switching control unit 2, and operates the hybrid vehicle 900 with the engine 100.As described above, in the fifth embodiment, a temperature measurement device that measures the water temperature or the outside air temperature of the internal combustion engine 100 (such as the water temperature sensor 122 illustrated in FIG. 1 ) is provided. The ignition control unit 83 is configured to include the switching control unit 2 that performs discharging of the ignition plug 200 while the hybrid vehicle is being operated with the HEV engine 600 before the operation of the engine 100 starts, and shifts from the operation with the HEV engine 600 to the operation with the engine 100 when the water temperature or outside air temperature of the engine 100 measured by the temperature measuring device becomes equal to or higher than a predetermined threshold temperature.With this configuration, the ignition device for an internal combustion engine includes the shift control unit 2 that determines whether to change the power source based on the temperature information of the internal combustion engine 100 or the outside air temperature information and that can correspondingly perform the switching from the HEV motor 600 to the internal combustion engine 100.[Sixth Embodiment]Next, an ignition device for an internal combustion engine according to a sixth embodiment will be described.FIG. 14 is a diagram for describing an engine ignition device according to the sixth embodiment.The ignition device for an internal combustion engine according to the sixth embodiment is different from the above-described embodiment in that the control of the pre-discharge is made different according to the stroke (intake stroke, compression stroke, combustion stroke, exhaust stroke) of each cylinder 150 in the combustion cycle of the internal combustion engine 100.In the ignition control unit 83 of the ignition device for an internal combustion engine according to the sixth embodiment, the stroke of the combustion cycle for each cylinder 150 is determined based on the crank angle of the crankshaft 123 detected by the above-described crank angle sensor 121.The ignition control unit 83 temporarily stores the stroke of each cylinder 150 when the internal combustion engine 100 has been stopped beforehand in a predetermined storage area of the RAM 40 of the control device 1.As illustrated in FIG. 14, in the embodiment, the state of the engine 100 at the time of the previous stop is an example when the first cylinder 150A is in the intake stroke, the second cylinder 150B is in the compression stroke, the third cylinder 150C is in the combustion stroke, and the cylinder 150D is in the exhaust stroke. In this case, in the running operation of the internal combustion engine 100, fuel is injected from the fuel injection valve 134 into the second cylinder 150B in the compression stroke.In this state, the ignition control unit 83 performs pre-discharge in the ignition coil 200A corresponding to the first cylinder 150A, which represents the previous stroke of the second cylinder 150B in which the fuel injection is performed.Further, the ignition control unit 83 not only performs pre-discharge of the ignition coil 200A corresponding to the first cylinder 150A in the preceding stroke of the second cylinder 250B in which the fuel injection is performed, but also performs the pre-discharge on the ignition coils 200B and 200D corresponding to the second cylinder 150B in which the fuel injection is performed and the fourth cylinder 150D in which the ejection is performed.In addition, the ignition control unit 83 may change the frequency or voltage (power) of the discharge of the ignition coil for each cylinder when the pre-discharge is performed on the ignition coils 200A, 200B, and 200D corresponding to a plurality of cylinders (for example, first cylinder 150A, second cylinder 150B, and fourth cylinder 150D) that are in a different stroke.For example, in the fourth cylinder 150D, in the discharge stroke, the gas overheated in the preceding compression stroke is discharged so that the discharge performance of a spark plug 200D of the fourth cylinder 150D is set to be larger than the discharge performance of the other cylinders. With this configuration, even when the spark plug 200D of the fourth cylinder 150D is cooled by the exhaust of the overheated gas, the spark plug 200D of the fourth cylinder 150D is overheated with a larger discharge performance, so that the temperature of the spark plug 200D can be overheated accordingly. In addition, the discharge performance of the spark plug 200A of the first cylinder 150A in the intake stroke may be decreased before the fuel is injected from the fuel injection valve 134 in the compression stroke. In this case, the overheating of the spark plug 200A can be performed efficiently in consideration of the energy saving.Even in this case, in the ignition device for an internal combustion engine, the temperatures of the spark plugs 200A to 200D may be increased in advance. In particular, by changing the discharge performance of the spark plugs corresponding to the cylinders in different cycles, the spark plugs 200A to 200D can be overheated in a more suitable manner.Further, the ignition device for an internal combustion engine of the invention can also be used for superheating a spark plug that performs a plurality of times of discharges (multiple discharges) in one combustion cycle. In this case, the spark plug 83 may be configured to change the frequency or voltage for each discharge in the multiple discharge.Specifically, in the first combustion cycle after the start of the operation of the internal combustion engine 100, the ignition control unit 83 maximizes the first discharge power of the multiple discharge when the spark plug 200 is coldest and gradually decreases the discharge power as the number of times of discharges increases.With this configuration, the first discharge power in the multiple discharge is increased and the spark plug 200 is overheated in a shorter time, so that the overheating of the spark plug 200 can be efficiently performed with the discharge of the smallest discharge power after the multiple discharge.In addition, the ignition control unit 83 may be configured to perform pre-discharge with a predetermined discharge power to overheat the gas in each cylinder 150. In this case, the ignition control unit 83 sets the discharge performance of the spark plug 200 on the basis of the intake gas temperature measured by the intake air temperature sensor 115 described above.Specifically, the ignition control unit 83 continuously performs the pre-discharge of the spark plug 200 a plurality of times until the intake gas temperature measured by the intake air temperature sensor 115 becomes equal to or higher than a predetermined threshold temperature. When the gas temperature in the cylinder 150 exceeds a predetermined threshold temperature, the pre-discharge of the spark plug 200 is ended.With this configuration, the ignition control unit 83 can suitably overheat the gas in each cylinder 150 together with the spark plug based on the measurement result of the intake air temperature sensor 115. Thus, the ignition of the gas in the fuel stroke may be performed accordingly.In addition, the ignition control unit 83 may be configured to perform pre-discharge of the spark plug 200 due to a state of health (SOH)) or a remaining amount of a battery used for driving the internal combustion engine 100. In this case, when the battery has a deteriorated state or the remaining amount is small, the ignition control unit 83 decreases the discharge power of the spark plug 200 to prevent further deterioration of the state of the battery or further consumption.With this configuration, the spark plug 200 can be overheated while ensuring the deteriorated state or the remaining amount of the battery that operates the internal combustion engine 100.In addition, as illustrated in FIG. 13, when the vehicle is the hybrid vehicle 900 driven by a combination of the engine 100 and the motor (for example, the HEV motor 600) illustrated in FIG. 13, generally, a battery having a voltage different from the battery (power supply) used for driving the engine 100 is used, and the battery (power supply) used for driving the HEV motor 600 is used for driving the engine 100.FIG. 15 is a diagram for describing the ignition of the spark plug 200.As illustrated in FIG. 15, for the spark plug 200, a battery (for example, 12 V) used for operating the internal combustion engine 100 is used after being charged to 10 kV to 30 kV, thereby performing ignition that exceeds the dielectric breakdown voltage of the gas in the cylinder 150. However, the spark plug 200 may continue (sustain) the ignition by applying a sustain voltage of about 300 V after charging the voltage to the dielectric breakdown voltage or more.Here, in this type of hybrid vehicle 900, a battery of about 300 V is used to operate the HEV motor 600. Thus, the inventor of the application has found that the ignition of the spark plug 200 can be maintained using the battery of the HEV engine 600.That is, the spark plug 200 increases the voltage of the battery (12 V) used to drive the internal combustion engine 100 from 10 kV to 30 kV, and ignites the spark plug 200 using this voltage (ignition at a voltage equal to or higher than the dielectric breakdown voltage). Thereafter, the ignition of the spark plug 200 is maintained by the battery (300 V) used to drive the HEV engine 600.As explained above, the hybrid vehicle 900 driven with a combination of the engine 100 and the HEV motor 600 includes a battery (first power supply) used to drive the engine 100 and a battery used to drive the HEV motor 600. The ignition control unit 83 ignites the fuel in the cylinder 150 by discharging the spark plug 200 using the battery (12 V) used to drive the internal combustion engine 100, and then discharges the spark plug 200 using the battery (300 V) used to drive the HEV engine 600.With this configuration, the consumption of the battery of the internal combustion engine 100 can be decreased compared to a case where the power of the battery used for driving the internal combustion engine 100 is increased and the spark plug 200 is ignited. Thus, deterioration of the state of the battery of the engine 100 can be prevented, and the battery can be downsized to the same extent as the battery consumption of the engine 100 is reduced.The control device 1 (vehicle control device) includes an ignition device for an internal combustion engine having the above-described configuration (at least one configuration including the spark plug 200, the ignition coil 300, and the ignition control unit 83). With the ignition device for an internal combustion engine, the internal combustion engine 100 can be controlled to prevent generation of hydrocarbons (HC) at the time of cold start.Although embodiments of the invention have been described by way of example, the invention may be carried out by combining all the embodiments or by correspondingly combining two or more embodiments.Further, the invention is not limited to any of all configurations of the above-described embodiments. A part of the configuration of the above-described embodiment may be replaced with the configuration of another embodiment. In addition, the configuration of the above-described embodiment may be replaced with the configuration of another embodiment.Further, a part of the configuration of the above-described embodiment may be added to, removed from, or replaced with the configuration of another embodiment.List of reference characters1 Control device 10 analog input unit 20 digital input unit 30 A / D converter 40 RAM 50 MPU 60 ROM 70 I / O port 80 output circuit 81 overall control unit 82 fuel injection control unit 83 ignition control unit 84 cylinder discrimination unit 85 angle information generation unit 86 rotational speed information generation unit 87 intake air amount measurement unit 88 load information generation unit 89 water temperature measurement unit 100 internal combustion engine 110 air filter 111 cold period 112 intake manifold 113 throttle valve 113 athrottle opening sensor 114 flow rate sensor 115 intake air temperature sensor 120 ring gear 121 crank angle sensor 122 water temperature sensor 123 crankshaft 125 accelerator pedal 126 accelerator pedal position sensor 130 fuel tank 131 fuel pump 132 pressure regulator 133 fuel line 134 fuel injection valve 140 combustion pressure sensor 150 cylinder 160 exhaust manifold 161 three-way catalyst 162 upstream air-fuel ratio sensor 163 downstream air-fuel ratio sensor 170 piston 200 spark plug 210 center electrode 220 outer electrode 230 insulator 300 ignition coil 310 primary coil 320 secondary coil 330 GS source 340 ignition electrode 400 circuit 500 circuit 550 semiconductor element 560 primary current control circuit R 1 resistor S ignition signal Ip primary current Vs secondary voltage

Claims

An ignition device for an internal combustion engine (100) in a vehicle (900) driven by combining the internal combustion engine (100) and an electric motor (600), comprising an ignition control unit (83) that discharges a spark plug (200) after the vehicle (900) is operated by the electric motor (600) before an operation of the internal combustion engine (100) is started; a temperature measurement device (122) that measures a water temperature of the internal combustion engine (100) or an outside air temperature, wherein the ignition control unit (83) discharges the spark plug (200) while the vehicle (900) is being operated by the electric motor (600) before starting the operation of the internal combustion engine (100), and comprises a switching control unit (2) configured to switch from the operation by the electric motor (600) to the operation by the internal combustion engine (100) when the water temperature of the internal combustion engine (100) or the outside air temperature measured by the temperature measurement device (122) is equal to or higher than a predetermined threshold temperature.The ignition device for an internal combustion engine (100) according to claim 1, wherein the ignition control unit (83) discharges the spark plug (200) in a state where fuel is not injected from a fuel injection valve (134) into the cylinder (150) of the internal combustion engine (100), based on detecting an operation signal of the vehicle (900) before the operation of the internal combustion engine (100) starts.The ignition device for an internal combustion engine (100) according to claim 2, further comprising: a stroke determination unit that determines a stroke in a combustion cycle of the cylinder (150); and a stroke storage unit that stores a stroke of the cylinder (150) determined by the stroke determination unit when the internal combustion engine (100) has stopped operation last time, wherein the ignition control unit (83) discharges the spark plug (200) corresponding to the cylinder (150) on the basis of a stroke of the cylinder (150) stored in the stroke storage unit at the time of a previous operation stop of the internal combustion engine (100).The ignition device for an internal combustion engine according to claim 3, wherein in a stroke of the cylinder (150) stored in the stroke storage unit at the time of the previous operation stop of the internal combustion engine (100), the ignition control unit (83) controls a discharge performance of a spark plug (200) corresponding to a cylinder (150) at a position in close proximity to a fuel injection position of the fuel injection valve (134) in a direction opposite to the direction of the fuel cycle to be larger than the discharge performance of a spark plug (200) associated with another cylinder (150).The ignition device for an internal combustion engine (100) according to claim 2, wherein the ignition control unit (83) discharges the spark plug (200) a plurality of times in a state where fuel is not injected from the fuel injection valve (134) into the cylinder (150) during operation of the electric motor (600) after the operation of the internal combustion engine (100) is started, and a frequency and a voltage are changed for each of the plurality of times of discharges.The ignition device for an internal combustion engine (100) according to claim 5, the temperature measurement device (122) comprising: an intake air temperature sensor (115) that measures an intake air temperature of gas sucked into the cylinder (150) of the internal combustion engine, wherein the ignition control unit (83) discharges the spark plug (200) until an intake temperature of the gas measured by the intake air temperature sensor (115) becomes equal to or higher than a predetermined temperature.The ignition device for an internal combustion engine (100) according to claim 1, wherein the ignition control unit (83) changes a stroke and a discharge voltage of the spark plug (200) according to a deteriorated state of a battery of the vehicle (900).The ignition device for an ignition control unit (83) according to claim 1, wherein a first power supply used for driving the internal combustion engine (100) and a second power supply used for driving the electric motor (600) are provided, and wherein after igniting fuel in the cylinder (150) of the internal combustion engine (100) by discharging the spark plug (200) using the first power supply, the ignition control unit (83) discharges the spark plug (200) using the second power supply.A control device for a vehicle (900), comprising: an ignition device for an internal combustion engine (100) according to any one of claims 1 to 8.

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