Ignition device and ignition method

Abstract

To provide a technique which can reduce adhesion amount of engine oil to an ignition plug in a motoring operation.SOLUTION: An ignition device 60 includes: an ignition plug 70 which is arranged in a cylinder 11 of an internal combustion engine 10; and an ignition circuit 80 which supplies high voltage to the ignition plug 70 and causes the ignition plug 70 to discharge. A control section 50 performs multiple discharge for causing the ignition plug 70 to discharge by a plurality of times by an ignition circuit 80 during one cycle of the internal combustion engine 10 during a motoring operation of a drive system. By this, engine oil adhering to the ignition plug 70 can be burned out by discharging in a plurality of times in the motoring operation. As a result, adhesion amount of engine oil to the ignition plug 70 can be reduced.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an ignition device and an ignition method for an internal combustion engine mounted in a drive system of a vehicle capable of switching between firing operation and motoring operation. [Background technology]

[0002] Conventionally, a hybrid vehicle drive system that uses both an internal combustion engine and a motor is known. A conventional drive system is described, for example, in Patent Document 1. This type of drive system can switch between a "firing operation" in which fuel is burned in the internal combustion engine, and a "motoring operation" in which no fuel is consumed.

[0003] Motoring operation is performed, for example, to consume battery power when power is accumulated near the upper limit of the battery capacity (see paragraph 0021 of Patent Document 1).Motoring operation is also performed to generate negative pressure when the negative pressure used for pedal braking, etc., becomes low (see paragraph 0010 of Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-079029 Summary of the Invention [Problem to be solved by the invention]

[0005] Spark plugs are arranged in the cylinders of an internal combustion engine to ignite fuel during firing operation. Engine oil, which lubricates the contact surfaces of the stems and head connections of the intake and exhaust valves that open and close at high speed, and engine oil, which lubricates the pistons and piston rings that reciprocate at high speed, can leak into the cylinders of the internal combustion engine and adhere to the spark plugs. If an excessive amount of engine oil adheres to the spark plugs, it becomes difficult for the spark plugs to ignite the fuel.

[0006] During firing operation, engine oil adhering to the ignition plug is removed by combustion in the cylinder. However, during motoring operation, fuel is not burned in the cylinder, so the amount of engine oil adhering to the ignition plug is likely to be excessive.

[0007] The present invention has been made in consideration of the above circumstances, and has an object to provide a technique capable of reducing the amount of engine oil adhering to the ignition plug during motoring operation. [Means for solving the problem]

[0008] In order to solve the above problems, the first invention is an ignition device for an internal combustion engine mounted on a drive system of a vehicle capable of switching between firing operation and motoring operation, comprising an ignition plug arranged in a cylinder of the internal combustion engine, an ignition circuit that supplies a high voltage to the spark plug to cause the spark plug to discharge, and a control unit that controls the ignition circuit, and when the drive system is in motoring operation, the control unit performs a multi-discharge that causes the ignition plug to discharge multiple times via the ignition circuit during one cycle of the internal combustion engine.

[0009] A second invention is an ignition device of the first invention, wherein the control unit performs multi-discharge according to the driving conditions of the vehicle even when the drive system is in the firing operation, and the number of discharges of the multi-discharge during the motoring operation is greater than the number of discharges of the multi-discharge during the firing operation.

[0010] A third invention is an ignition device of the first or second invention, wherein the control unit determines whether the motoring operation is a first motoring operation for consuming surplus power or a second motoring operation for generating negative pressure, and the number of discharges of the multi-discharge in the case of the first motoring operation is greater than the number of discharges of the multi-discharge in the case of the second motoring operation.

[0011] A fourth invention is an ignition device of the first or second invention, wherein the control unit determines whether the motoring operation is a first motoring operation for consuming surplus power or a second motoring operation for generating negative pressure, and the energy supplied to the spark plug in the case of the first motoring operation is greater than the energy supplied to the spark plug in the case of the second motoring operation.

[0012] A fifth invention is an ignition device of the third or fourth invention, wherein the control unit is capable of controlling the throttle opening to adjust the amount of air intake into the cylinder, and the throttle opening in the case of the first motoring operation is made larger than the throttle opening in the case of the second motoring operation.

[0013] A sixth invention is an ignition device of any one of the first to fifth inventions, further comprising a temperature sensor that detects a temperature correlated with the temperature of the spark plug, and the control unit increases the number of discharges of the spark plug in one cycle as the detection value of the temperature sensor becomes lower.

[0014] A seventh invention is an ignition device of any one of the first to fifth inventions, further comprising a temperature sensor that detects a temperature correlated with the temperature of the spark plug, and the control unit increases the energy of a single discharge in the spark plug as the detection value of the temperature sensor becomes lower.

[0015] The eighth invention is an ignition method for an internal combustion engine mounted on a drive system of a vehicle capable of switching between firing operation and motoring operation, wherein when the drive system is in motoring operation, a multi-discharge is performed to discharge an ignition plug multiple times during one cycle of the internal combustion engine. Effect of the Invention

[0016] According to the first to eighth aspects of the present invention, engine oil adhering to the spark plug during motoring is burned off by multiple discharges. This reduces the amount of engine oil adhering to the spark plug.

[0017] In particular, according to the second aspect of the present invention, engine oil adhering to the spark plug can be more effectively burned off during motoring operation.

[0018] In particular, according to the third aspect of the present invention, surplus power is utilized to generate discharges more frequently, thereby making it possible to more effectively burn off engine oil adhering to the spark plug.

[0019] In particular, according to the fourth aspect of the present invention, surplus power is utilized to generate a higher energy discharge, which makes it possible to more effectively burn off engine oil adhering to the spark plug.

[0020] In particular, according to the fifth aspect of the present invention, in the case of the second motoring operation for generating negative pressure, the negative pressure in the cylinder is increased, while in the case of the first motoring operation for consuming surplus power, the throttle opening is increased to reduce the negative pressure in the cylinder, thereby suppressing the intrusion of engine oil into the cylinder. Also, in the case of the first motoring operation, the intake air is increased to increase the air pressure in the cylinder, thereby increasing the secondary voltage of the discharge, and the engine oil adhering to the spark plug can be burned off more effectively.

[0021] In particular, according to the sixth aspect of the present invention, at low temperatures, engine oil is more likely to adhere to the spark plug, so that more discharges occur, thereby making it possible to effectively burn off the engine oil adhering to the spark plug.

[0022] In particular, according to the seventh aspect of the present invention, at low temperatures, engine oil is more likely to adhere to the ignition plug, and therefore a higher energy discharge is performed, thereby making it possible to effectively burn off the engine oil adhering to the ignition plug.

[0023] In particular, according to the eighth aspect of the present invention, engine oil adhering to the ignition plug during motoring can be burned off by multiple discharges. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a diagram showing the flow of power / electricity in the drive system during firing operation. [Diagram 2] FIG. 2 is a diagram showing the flow of power / electricity in the drive system during motoring operation. [Diagram 3] 1 is a diagram showing a configuration of one cylinder of an internal combustion engine and an ignition device connected to the cylinder. [Figure 4] 4 is a flowchart showing the flow of a discharge operation by the ignition device. [Diagram 5] 5 is a flowchart showing a process for switching a discharging operation according to an operation mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] <1. Drive system> 1 and 2 are diagrams showing the flow of power / electricity in a drive system 1 according to one embodiment of the present invention. The drive system 1 is a system that is mounted on a vehicle such as an automobile and supplies power to wheels 9 in a so-called hybrid system. As shown in Fig. 1 and Fig. 2, the drive system 1 includes an internal combustion engine 10, a first motor 20, a second motor 30, a battery 40, and a control unit 50. Both the first motor 20 and the second motor 30 are so-called motor generators that are capable of generating electricity and driving.

[0027] The internal combustion engine 10 is an engine that outputs power by combusting fuel such as gasoline in its cylinders.

[0028] The first motor 20 is provided between the internal combustion engine 10 and the battery 40. During firing operation, which will be described later, the first motor 20 operates as a generator that generates electricity using power output from the internal combustion engine 10. Furthermore, during motoring operation, which will be described later, the first motor 20 operates as an electric motor that operates the piston of the internal combustion engine 10 using power supplied from the battery 40.

[0029] The second motor 30 is a motor connected to the wheels 9. During firing operation, which will be described later, the second motor 30 operates as an electric motor that rotates the wheels 9 using power supplied from a battery 40. During motoring operation, which will be described later, the second motor 30 operates as a generator that generates power using the rotation of the wheels 9.

[0030] The battery 40 is a storage battery capable of storing and discharging electric power. The battery 40 stores electric power supplied from the motor that operates as a generator out of the first motor 20 and the second motor 30. The battery 40 also supplies electric power to the motor that operates as an electric motor out of the first motor 20 and the second motor 30.

[0031] The control unit 50 is a unit that controls the operation of each part of the drive system 1. The control unit 50 is, for example, an ECU (Electronic Control Unit). The control unit 50 is configured by a computer having a CPU and a memory. The control unit 50 is electrically connected to the first motor 20, the second motor 30, the battery 40, and an ignition device 60 described later. The control unit 50 controls the operation of each of the above-mentioned parts according to a predetermined program. This realizes switching of operation modes described later and the operation of the internal combustion engine 10, the first motor 20, the second motor 30, and the ignition device 60 in each operation mode.

[0032] <2. Firing operation and motoring operation> The drive system 1 can operate in two driving modes: "firing operation" and "motoring operation." Firing operation is a driving mode in which the vehicle runs by consuming fuel. Motoring operation is a driving mode in which the vehicle runs without consuming fuel. The drive system 1 switches between these two driving modes depending on the driving conditions of the vehicle.

[0033] 1 shows the operation of the drive system 1 during firing operation. During firing operation, power is output from the internal combustion engine 10 by burning fuel such as gasoline in the cylinders of the internal combustion engine 10. The first motor 20 generates power using the power output from the internal combustion engine 10. The battery 40 accumulates the power supplied from the first motor 20 and supplies the power to the second motor 30. The second motor 30 outputs power using the power supplied from the battery 40. The wheels 9 rotate using the power output from the second motor 30.

[0034] 2 shows the operation of the drive system 1 during motoring. During motoring, the second motor 30 generates electricity through the rotation of the wheels 9. The battery 40 stores the power supplied from the second motor 30 and supplies the power to the first motor 20. The first motor 20 outputs power using the power supplied from the battery 40. The internal combustion engine 10 reciprocates pistons in the cylinders using the power output from the first motor 20 without injecting fuel into the cylinders.

[0035] The drive system 1 performs motoring operation in the following two cases.

[0036] The first case is when the power stored in the battery 40 approaches the upper limit of the battery's 40 storage capacity. For example, when the vehicle is traveling downhill, the battery 40 is charged by regenerative braking. However, if the downhill stretch continues for a long time, the power stored in the battery 40 reaches the upper limit of the battery's 40 storage capacity. When this happens, the regenerative braking becomes less effective. Therefore, the drive system 1 performs the motoring operation described above, so that the power stored in the battery 40 is consumed by the first motor 20 and the internal combustion engine 10. This motoring operation for consuming surplus power stored in the battery 40 is hereinafter referred to as the "first motoring operation."

[0037] The second is when the negative pressure used for pedal braking, etc., becomes low. In this case, the motoring operation described above is performed to reciprocate the piston in the cylinder of the internal combustion engine 10. Then, the negative pressure generated in the cylinder when the piston is pulled is accumulated in a negative pressure source in the vehicle. This motoring operation for generating negative pressure is hereinafter referred to as the "second motoring operation."

[0038] <3. Internal combustion engine> FIG. 3 is a diagram showing a configuration of one cylinder 11 of the internal combustion engine 10 and an ignition device 60 connected to the cylinder 11. As shown in FIG.

[0039] 3, the internal combustion engine 10 has a cylinder 11 which is a combustion chamber, and a piston 12 which reciprocates within the cylinder 11. An intake pipe 13 and an exhaust pipe 14 are connected to the cylinder 11.

[0040] An intake valve 15 is provided at a connection port 131 between the intake pipe 13 and the cylinder 11. A throttle 16 is also provided at the intake pipe 13. The throttle 16 is a flow control valve that adjusts the amount of intake air into the cylinder 11. When the intake valve 15 and the throttle 16 are open and the piston 12 descends, gas is supplied from the intake pipe 13 to the cylinder 11. At this time, during firing operation, a mixture of fuel and air is supplied into the cylinder 11. On the other hand, during motoring operation, air that does not contain fuel is supplied into the cylinder 11.

[0041] An exhaust valve 17 is provided at a connection port 141 between the exhaust pipe 14 and the cylinder 11. When the piston 12 rises with the exhaust valve 17 open, the gas in the cylinder 11 is discharged to the exhaust pipe 14. When the piston 12 rises with the intake valve 15 and the exhaust valve 17 closed, the gas in the cylinder 11 is compressed.

[0042] <4. Ignition device> The ignition device 60 is a device that ignites the fuel supplied into the cylinder 11. As shown in FIG.

[0043] The spark plug 70 is disposed in the cylinder 11 of the internal combustion engine 10. Specifically, the spark plug 70 is attached to a position at the upper end of the cylinder 11 between a connection port 131 of the intake pipe 13 and a connection port 141 of the exhaust pipe 14. The spark plug 70 has a center electrode 71 and a ground electrode 72. The center electrode 71 is electrically connected to a secondary coil 812, which will be described later. The ground electrode 72 is grounded to the ground via the cylinder 11.

[0044] The temperature sensor 73 is a sensor that detects a temperature that is correlated with the temperature of the spark plug 70. The temperature sensor 73 is connected, for example, to a flow path piping of cooling water for cooling the internal combustion engine 10. The temperature sensor 73 outputs a signal indicating the detected temperature to the control unit 50.

[0045] The ignition circuit 80 is a circuit that supplies a high voltage to the spark plug 70 to cause the spark plug 70 to discharge. As shown in FIG.

[0046] The ignition coil 81 is a coil unit that boosts the power supply voltage. The ignition coil 81 has a primary coil 811, a secondary coil 812, and an iron core 813. The primary coil 811 and the secondary coil 812 are electromagnetically coupled via the iron core 813. The number of turns of the secondary coil 812 is greater than the number of turns of the primary coil 811.

[0047] One end of the primary coil 811 is electrically connected to the battery 40 via a power line w1. The other end of the primary coil 811 is grounded to the ground via a ground line w2. A switching element 82 is inserted in the ground line w2.

[0048] One end of the secondary coil 812 is electrically connected to a connection part w3 located on the path of the power line w1 via a first connection line w4. A diode 85 is inserted in the first connection line w4. The diode 85 is connected in series to the secondary coil 812 with the forward direction being the direction from the secondary coil 812 to the connection part w3. The other end of the secondary coil 812 is electrically connected to the center electrode 71 of the spark plug 70 via a second connection line w5.

[0049] The switching element 82 is a switch that switches ON / OFF of the current supply from the battery 40 to the primary coil 811. For example, an IGBT (Insulated Gate Bipolar Transistor) is used for the switching element 82. The collector of the switching element 82 is electrically connected to the other end of the primary coil 811. The emitter of the switching element 82 is connected to the ground.

[0050] The control unit 50 is electrically connected to the switching element 82. The control unit 50 controls the ON / OFF of the switching element 82 by outputting a control signal to the switching element 82. As shown in Fig. 3, the control unit 50 of this embodiment is also electrically connected to the throttle 16. The control unit 50 can control the opening degree of the throttle 16 by outputting a control signal to the throttle 16.

[0051] <5. Discharge operation> Fig. 4 is a flowchart showing the flow of the discharge operation by the ignition device 60. The processing in Fig. 4 is realized by the above-mentioned control unit 50 controlling the operation of each part of the ignition device 60 in accordance with a program.

[0052] When discharging the spark plug 70, the ignition device 60 first energizes the primary coil 811 (step SA). Specifically, the control unit 50 switches the switching element 82 from OFF (open state) to ON (closed state). This causes a primary current to flow from the battery 40 to the ground via the power line w1, the primary coil 811, and the ground line w2. As a result, primary energy is stored in the ignition coil 81.

[0053] Thereafter, the control unit 50 switches the switching element 82 from ON (closed state) to OFF (open state), thereby cutting off the current to the primary coil 811 (step SB). Then, an induced electromotive force is induced in the secondary coil 812 via the iron core 813, and a high voltage corresponding to the above-mentioned primary energy is generated in the secondary coil 812.

[0054] When a high voltage is generated in the secondary coil 812, a high voltage is also generated between the center electrode 71 and the ground electrode 72 of the spark plug 70. For example, the voltage value of the center electrode 71 becomes several thousand volts to several tens of thousands volts lower than the voltage value (ground voltage) of the ground electrode 72. This high voltage causes a dielectric breakdown between the center electrode 71 and the ground electrode 72 of the spark plug 70, causing a spark discharge between the two electrodes.

[0055] The internal combustion engine 10 repeatedly takes in air into the cylinder 11 and exhausts air from the cylinder 11 by sequentially opening and closing the intake valve 15 and the exhaust valve 17 and reciprocating the piston 12. During one cycle of intake and exhaust, the above-mentioned discharge operation is performed once or multiple times. During firing operation, the sparks generated by this discharge combust the fuel supplied into the cylinder 11 of the internal combustion engine 10.

[0056] <6. Switching the discharge operation according to the operation mode> 5 is a flowchart showing a process for switching the discharge operation according to the operation mode. The process in FIG. 5 is realized by the above-mentioned control unit 50 controlling the operation of each part of the ignition device 60 according to a program.

[0057] In the following, performing the above-mentioned discharge operation only once during one cycle of intake and exhaust for the cylinder 11 is referred to as "single discharge." Performing the above-mentioned discharge operation multiple times during one cycle of intake and exhaust for the cylinder 11 is referred to as "multiple discharge."

[0058] 5, the control unit 50 first determines whether the drive system 1 is in firing operation or motoring operation (step S1). If the drive system 1 is in firing operation (step S1: No), the ignition device 60 performs a discharge operation for firing operation (step S2). Specifically, the control unit 50 causes the ignition device 60 to perform single discharge or multiple discharge depending on the running conditions of the vehicle.

[0059] On the other hand, if the drive system 1 is in motoring operation (step S1: Yes), the control unit 50 determines whether the motoring operation is the first motoring operation or the second motoring operation (step S3).

[0060] When the drive system 1 is in the second motoring operation (step S3: No), the ignition device 60 performs a multi-discharge (step S4). That is, the ignition device 60 executes discharge of the spark plug 70 multiple times during one cycle from intake to exhaust for the cylinder 11.

[0061] On the other hand, if the drive system 1 is in the first motoring operation (step S3: Yes), the control unit 50 changes the voltage supplied to the primary coil 811 and the energization time (step S5). Specifically, the voltage supplied from the battery 40 to the primary coil 811 for discharging is increased to be higher than the voltage during the second motoring operation. Then, the time during which electricity is applied to the primary coil 811 for discharging is made shorter than the energization time during the second motoring operation.

[0062] Furthermore, the control unit 50 makes the opening of the throttle 16 larger than the opening during the second motoring operation (step S6). Then, the ignition device 60 performs multiple discharges based on the changed voltage and current application time. That is, the ignition device 60 executes discharge of the spark plug 70 multiple times during one cycle from intake to exhaust for the cylinder 11 (step S7).

[0063] Some of the engine oil used to lubricate the piston 12, intake valve 15, exhaust valve 17, etc. leaks into the cylinder 11. The engine oil leaking into the cylinder 11 may adhere to the spark plug 70. If an excessive amount of engine oil adheres to the spark plug 70, it becomes difficult for the spark plug 70 to ignite the fuel during firing operation.

[0064] During firing operation, engine oil adhering to the spark plug 70 is removed by combustion in the cylinder 11. However, during motoring operation, since fuel is not burned in the cylinder 11, the amount of engine oil adhering to the spark plug 70 is likely to become excessive. Therefore, as described above, when the drive system 1 is in motoring operation, the control unit 50 performs multi-discharge, which causes the ignition circuit 80 to discharge the spark plug 70 multiple times during one cycle of the internal combustion engine 10. In this way, the engine oil adhering to the spark plug 70 can be burned off by multiple discharges. Therefore, the amount of engine oil adhering to the spark plug 70 can be reduced.

[0065] In particular, sufficient power is stored in the battery 40 during the first motoring operation. Therefore, in the example of FIG. 5, the voltage supplied from the battery 40 to the primary coil 811 during the first motoring operation is increased to be higher than the voltage supplied from the battery 40 to the primary coil 811 during the second motoring operation. In this way, the time during which current is applied to the primary coil 811 during the first motoring operation can be shortened, and the number of multiple discharges during one cycle can be increased. As a result, the energy supplied to the spark plug 70 during the first motoring operation can be made larger than the energy supplied to the spark plug 70 during the second motoring operation. That is, the surplus power can be used to perform a higher energy discharge. This allows the engine oil adhering to the spark plug 70 to be burned off more effectively.

[0066] 5, the opening of the throttle 16 in the first motoring operation is set to be larger than the opening of the throttle 16 in the second motoring operation. In this way, in the second motoring operation for generating negative pressure, the negative pressure in the cylinder 11 is increased, while in the first motoring operation for consuming surplus power, the opening of the throttle 16 is increased to reduce the negative pressure in the cylinder 11, thereby suppressing the intrusion of engine oil into the cylinder 11. In addition, in the first motoring operation, the intake air is increased to increase the air pressure in the cylinder 11, thereby increasing the secondary voltage of the discharge, and the engine oil adhering to the spark plug 70 can be burned off more effectively.

[0067] The number of times of multi-discharge during motoring operation may be greater than the number of times of multi-discharge during firing operation. For example, during firing operation, the spark plug 70 may be discharged two times during one cycle of the internal combustion engine 10, and during motoring operation, the spark plug 70 may be discharged three times during one cycle of the internal combustion engine 10. This allows the engine oil adhering to the spark plug 70 to be burned off more effectively.

[0068] Furthermore, sufficient power is stored in the battery 40 during the first motoring operation. For this reason, the number of times of multi-discharge during the first motoring operation may be greater than the number of times of multi-discharge during the second motoring operation. For example, during the second motoring operation, the spark plug 70 may be discharged two times during one cycle of the internal combustion engine 10, and during the first motoring operation, the spark plug 70 may be discharged three times during one cycle of the internal combustion engine 10. In this way, by using the surplus power of the battery 40 to perform a greater number of discharges, the engine oil adhering to the spark plug 70 can be burned off more effectively.

[0069] Furthermore, when the temperature of the spark plug 70 is low, the amount of engine oil adhering to the spark plug 70 is more likely to increase. Furthermore, when the temperature of the spark plug 70 is low, the temperature of the spark plug 70, which rises due to discharge, is less likely to reach a safety upper limit. Therefore, the control unit 50 may refer to the detection value of the temperature sensor 73, and increase the number of discharges of the spark plug 70 in one cycle as the detection value becomes lower. This allows the engine oil adhering to the spark plug 70 to be effectively burned off.

[0070] Furthermore, the control unit 50 may increase the energy of one discharge in the spark plug 70 as the detection value of the temperature sensor 73 decreases. This allows the engine oil adhering to the spark plug 70 to be burned off more effectively.

[0071] <7. Variations> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0072] In the above embodiment, the voltage supplied to the primary coil 811, the energization time, and the opening of the throttle 16 are changed between the first motoring operation and the second motoring operation. However, multiple discharge may be performed under the same conditions during both the first motoring operation and the second motoring operation.

[0073] In the above embodiment, during firing operation, the second motor 30 rotates the wheels 9 using the electric power generated by the internal combustion engine 10 and the first motor 20. However, during firing operation, the wheels 9 may be directly rotated by the power output from the internal combustion engine 10.

[0074] In addition, the detailed configurations of the ignition device and the drive system may be modified as appropriate without departing from the spirit of the present invention. Furthermore, the elements appearing in the above-described embodiment and modified examples may be combined as appropriate without causing any contradiction. [Explanation of symbols]

[0075] 1. Drive system 9 wheels 10 Internal combustion engine 11 cylinders 12 Piston 13 Intake pipe 14 Exhaust pipe 15 Intake valve 16 Throttle 17 Exhaust valve 20 First motor 30 Second motor 40 Battery 50 Control section 60 Ignition system 70 Spark plug 71 Center electrode 72 Ground electrode 73 Temperature Sensor 80 ignition circuit 81 Ignition coil 82 Switching element 85 Diode 131 Connection port 141 Connection port 811 Primary coil 812 Secondary coil 813 Iron core

Claims

1. An ignition device for an internal combustion engine mounted in a drive system of a vehicle capable of switching between firing operation and motoring operation, a spark plug disposed in a cylinder of the internal combustion engine; an ignition circuit that supplies a high voltage to the spark plug to cause the spark plug to discharge; A control unit for controlling the ignition circuit; Equipped with The control unit performs a multi-discharge by causing the ignition plug to discharge a plurality of times via the ignition circuit during one cycle of the internal combustion engine when the drive system is in the motoring operation.

2. 2. The ignition device according to claim 1, The control unit performs multi-discharge according to the driving conditions of the vehicle even when the drive system is in the firing operation, An ignition device, wherein the number of discharges of the multi-discharge during the motoring operation is greater than the number of discharges of the multi-discharge during the firing operation.

3. 2. The ignition device according to claim 1, The control unit is determining whether the motoring operation is a first motoring operation for consuming surplus power or a second motoring operation for generating negative pressure; An ignition device, wherein the number of discharges of the multi-discharge in the first motoring operation is greater than the number of discharges of the multi-discharge in the second motoring operation.

4. 2. The ignition device according to claim 1, The control unit is determining whether the motoring operation is a first motoring operation for consuming surplus power or a second motoring operation for generating negative pressure; An ignition device, wherein the energy supplied to the spark plug in the first motoring operation is greater than the energy supplied to the spark plug in the second motoring operation.

5. The ignition device according to claim 3 or 4, The control unit is The throttle opening that adjusts the amount of intake air to the cylinder is controllable, an ignition device that makes the opening degree of the throttle in the first motoring operation larger than the opening degree of the throttle in the second motoring operation.

6. An ignition device according to any one of claims 1 to 4, A temperature sensor for detecting a temperature correlated with the temperature of the spark plug Further equipped with The control unit is An ignition device that increases the number of discharges of the spark plug in one cycle as the detection value of the temperature sensor decreases.

7. 6. The ignition device according to claim 5, A temperature sensor for detecting a temperature correlated with the temperature of the spark plug Further equipped with The control unit is An ignition device that increases the number of discharges of the spark plug in one cycle as the detection value of the temperature sensor decreases.

8. An ignition device according to any one of claims 1 to 4, A temperature sensor for detecting a temperature correlated with the temperature of the spark plug Further equipped with The control unit is An ignition device that increases the energy of one discharge in the spark plug as the detected value of the temperature sensor decreases.

9. 6. The ignition device according to claim 5, A temperature sensor for detecting a temperature correlated with the temperature of the spark plug Further equipped with The control unit is An ignition device that increases the energy of one discharge in the spark plug as the detected value of the temperature sensor decreases.

10. A method for igniting an internal combustion engine mounted in a drive system of a vehicle capable of switching between firing operation and motoring operation, comprising: An ignition method comprising the steps of: performing a multi-discharge by discharging an ignition plug a plurality of times during one cycle of the internal combustion engine when the drive system is in the motoring operation.

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