WO2016157541A1

WO2016157541A1 - Ignition device for internal combustion engine

Info

Publication number: WO2016157541A1
Application number: PCT/JP2015/060681
Authority: WO
Inventors: 義文内勢
Original assignee: 日立オートモティブシステムズ阪神株式会社
Priority date: 2015-03-30
Filing date: 2015-03-30
Publication date: 2016-10-06
Also published as: JP6411636B2; JPWO2016157541A1

Abstract

Provided is an ignition device for an internal combustion engine with which it is possible to maintain stable combustion without increasing the time of current conduction to a primary coil. An ignition coil 113 is configured from a main primary coil 111a for generating an interrupting magnetic flux by interrupting the current after current conduction has been initiated at a prescribed timing in a combustion cycle, a sub primary coil 111b for generating an additional magnetic flux in the same direction as the interrupting magnetic flux by current conduction at any desired timing from the time of the interrupting magnetic flux generation onward, and a secondary coil 112 in which electrical discharge energy is generated using the interrupting magnetic flux and the additional magnetic flux via a center core 113, a suitable electrical discharge pattern being achieved in the internal combustion engine and stable combustion in the internal combustion engine being maintained by regulating the timing at which the additional magnetic flux is generated and the time duration for which the additional magnetic flux is continued.

Description

Ignition device for internal combustion engine

The present invention relates to an ignition device for an internal combustion engine mounted on a motor vehicle, and obtains good discharge characteristics by increasing the discharge energy generated on the secondary side of the ignition coil in a superimposed manner.

Direct-injection engines and high-EGR engines have been adopted as internal combustion engines mounted on vehicles to improve fuel efficiency, but these engines are not very ignitable, so a high-energy ignition system is required. Become. In view of this, a phase discharge ignition device has been proposed in which the output of another ignition coil is additionally superimposed on the secondary output of the ignition coil generated by the classic current interruption principle (for example, Patent Document 1). See).
According to the ignition device described in Patent Document 1, by interrupting the primary current of the main ignition coil, the high voltage of several kV generated on the secondary side thereof causes dielectric breakdown in the discharge gap of the spark plug, thereby igniting. After starting the discharge current from the secondary side of the coil, the primary current of the auxiliary ignition coil connected in parallel with the main ignition coil is cut off, and a DC voltage of several kV generated on the secondary side is additionally superimposed. By doing so, since a large discharge energy can be given to the spark plug for a relatively long time, the ignitability to the fuel is improved, and the fuel consumption is also improved.

JP 2012-140924 A

However, in the system such as the ignition device described in Patent Document 1, the ignition phase of the two ignition coils is increased in order to lengthen the discharge time of the spark plug. In addition to being long, the time for accumulating sufficient energy in the two ignition coils also increases, so the combustion rate cannot be increased. For this reason, the ignition device described in Patent Document 1 can stabilize engine output by maintaining stable combustion, but cannot increase the rotational speed so that high output can be obtained at a necessary timing.
Further, as a method of increasing the energy accumulated in the coil without increasing the energization time to the primary coil, a method of increasing the physique of the coil and increasing the number of turns of the coil, and a method of using a plurality of ignition coils are conceivable. However, if a large ignition coil is used or a plurality of ignition coils are used, securing the mounting space becomes a problem, and the cost increases considerably.
In addition, by increasing the power supply voltage outside or inside the coil and supplying current from the primary coil low voltage side, or by applying a high voltage directly to the secondary side of the coil, the energization time to the primary coil can be reduced. A method of increasing the discharge energy on the secondary side without increasing the length is also conceivable. However, these methods require a booster circuit and the like, so that a space for mounting the booster circuit and the like must be secured, and the cost is considerably increased.
Therefore, the present invention has an object to provide an ignition device for an internal combustion engine that can maintain stable combustion without increasing the energization time of the primary coil, and that can suppress the increase in size and cost of the ignition coil. To do.

In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a main primary coil in which a forward energizing magnetic flux is generated by energization and a reverse interrupting magnetic flux is generated by interrupting the current, and the interrupting magnetic flux is energized by energization. An ignition coil having a secondary primary coil that generates additional magnetic flux in the same direction, and a secondary coil that is connected to an ignition plug at one end and generates magnetic discharge energy by the magnetic flux generated in the primary primary coil and the secondary primary coil. Main switch means for switching energization / cutoff to the primary primary coil of the ignition coil, sub switch means for switching energization / cutoff to the sub primary coil of the ignition coil, and switching between the main switch means and the sub switch means Ignition control means for generating discharge sparks in the spark plug at a predetermined timing of the combustion cycle by controlling the operation, and the ignition control The stage is characterized in that the discharge energy generated in the secondary coil is increased in a superimposed manner by energizing the sub-primary coil for a predetermined superimposition time after the shut-off timing when the energization to the main primary coil is interrupted. And
According to a second aspect of the present invention, in the ignition device for an internal combustion engine according to the first aspect, a single DC power source is shared for power supply to the main ignition coil and the sub ignition coil of the ignition coil. It is characterized by that.
According to a third aspect of the present invention, in the internal combustion engine ignition device according to the second aspect, a voltage generated in the sub-primary coil due to a change in magnetic flux when the energization to the main primary coil is interrupted is a power supply voltage. The number of turns of the sub primary coil is set so as to be smaller.
According to a fourth aspect of the present invention, there is provided an internal combustion engine ignition device according to any one of the first to third aspects, wherein the main switch means is connected between the main ignition coil and a ground point. And a bypass line connected in parallel with the rectifying means that is forward in the direction from the grounding point side toward the ignition coil side.
The invention according to claim 5 is the internal combustion engine ignition device according to any one of claims 1 to 4, wherein the ignition control means is configured to control the auxiliary ignition coil based on a driving state of the vehicle. It is characterized in that the energization start timing is determined.
The invention according to claim 6 is the internal combustion engine ignition device according to any one of claims 1 to 5, wherein the ignition control means is configured to control the auxiliary ignition coil based on a driving state of the vehicle. The energization time is determined.
Further, the invention according to claim 7 is the internal combustion engine ignition device according to any one of claims 1 to 6, wherein the sub-switch means is capable of high-speed switching capable of sufficiently following an input short pulse. The ignition control means performs PWM control of the sub switch means with a pulse signal having a duty ratio determined based on a driving situation of the vehicle.
The invention according to claim 8 is the internal combustion engine ignition device according to claim 5 or claim 6, further comprising secondary current detection means for detecting a secondary current flowing on the secondary side of the ignition coil. The ignition control means determines the driving situation of the vehicle based on the secondary current detected by the secondary current detection means.
The invention according to claim 9 is the ignition device for an internal combustion engine according to any one of claims 1 to 8, wherein a plurality of ignition coils, main switch means and sub-switches corresponding to each ignition coil are provided. A switch means is provided, and secondary coils in all ignition coils are connected in parallel to the ignition plug, and energization / cutoff to the primary primary coil and sub primary coil in all ignition coils is controlled by the ignition control means It was made to do.
The invention according to claim 10 is the ignition device for an internal combustion engine according to any one of claims 1 to 8, wherein a plurality of ignition coils, main switch means and sub-switches corresponding to each ignition coil are provided. Each switch means is provided, and secondary coils in all ignition coils are connected in series with the spark plugs, and energization / cutoff to the primary primary coil and sub primary coil in all ignition coils is controlled by the ignition control means. It was made to do.
The invention according to claim 11 is the internal combustion engine ignition device according to any one of claims 1 to 10, wherein the ignition control means controls the operation of the internal combustion engine in an integrated manner. It is incorporated in the engine drive control device and is characterized in that the internal combustion engine drive control device performs ignition control of all cylinders.
The invention according to claim 12 is the ignition device for an internal combustion engine according to any one of claims 1 to 10, wherein the ignition control means is provided for each cylinder, and operates the internal combustion engine. The ignition control of the corresponding cylinder is performed based on an ignition instruction from an internal combustion engine drive control device that performs overall control.
The invention according to claim 13 is the ignition device for an internal combustion engine according to any one of claims 1 to 12, wherein at least the ignition coil and a main coil provided corresponding to the ignition coil are provided. The switch means and the sub switch means are housed in one case and unitized.

According to the ignition device for an internal combustion engine according to the present invention, the discharge energy generated in the secondary coil is superimposed by energizing the sub-primary coil for a predetermined superimposition time after the shut-off timing when the energization to the main primary coil is interrupted. Therefore, stable combustion can be maintained. In addition, by providing the secondary primary coil, the ignition coil is not significantly increased in size and the cost can be suppressed.

FIG. 1 is a schematic configuration diagram showing a first embodiment of an internal combustion engine ignition device according to the present invention.
FIG. 2 is an explanatory diagram showing a change in magnetic flux on the primary side in the ignition coil of the ignition device for an internal combustion engine according to the present invention.
FIG. 3 is a discharge waveform diagram in the internal combustion engine ignition device of the first embodiment.
FIG. 4 is a schematic configuration diagram showing a second embodiment of the internal combustion engine ignition device according to the present invention.
FIG. 5 is a discharge waveform diagram when the sub IGBT is operated by PWM control in the internal combustion engine ignition device of the first embodiment.
FIG. 6 is a schematic configuration diagram showing an ignition coil unit used in the third embodiment of the internal combustion engine ignition device according to the present invention.
FIG. 7 is a discharge waveform diagram in the internal combustion engine ignition device of the third embodiment.
FIG. 8 is a schematic configuration diagram showing an ignition coil unit used in the fourth embodiment of the ignition device for an internal combustion engine according to the present invention.
FIG. 9 is a discharge waveform diagram in the internal combustion engine ignition device of the fourth embodiment.
FIG. 10 is a schematic configuration diagram showing an ignition coil unit used in the fifth embodiment of the internal combustion engine ignition device according to the present invention.

Next, an embodiment of an ignition device for an internal combustion engine according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an internal combustion engine ignition device 1 according to a first embodiment of the present invention. An ignition coil unit 10 that generates a discharge spark in one ignition plug 2 provided for each cylinder of the internal combustion engine, And ignition control means 3a for controlling the operation of the ignition coil unit 10.
The ignition control means 3a shown in the present embodiment is included in the engine control unit 3 that is an internal combustion engine control device that comprehensively controls the internal combustion engine of the automobile, and an ignition signal from the engine control unit 3 (later As will be described in detail, the operation of the ignition coil unit 10 is appropriately controlled.
The ignition coil unit 10 is, for example, a unit in which an ignition coil 11, a main IGBT (Insulated Gate Bipolar Transistor) 12a, and a sub-IGBT 12b are housed in a case 13 having a required shape. A high voltage terminal 131 and a connector 132 are provided at appropriate positions of the case 13, and the ignition plug 2 is connected via the high voltage terminal 131 and also connected to the engine control unit 3 via the connector 132.
The ignition coil 11 causes a magnetic flux generated in the main primary coil 111a and the sub primary coil 111b to act on the secondary coil 112 by energization / cutoff control from the engine control unit 3, and for example, the main primary so as to surround the center core 113. The coil 111a and the sub-primary coil 111b are disposed, and the secondary coil 112 is disposed outside thereof. One ends of the main primary coil 111a and the sub primary coil 111b are connected to a DC power supply 4 such as a vehicle battery, and a common power supply voltage VB + is applied.
The other end of main primary coil 111a is connected to ground point GND through main IGBT 12a. The main IGBT 12a is a semiconductor element capable of high-power high-speed switching, and functions as main switch means for switching energization / cut-off to the main primary coil 111a based on the main primary coil ignition signal Sa from the ignition control means 13. To do.
The other end of the sub primary coil 111b is connected to the ground point GND through the sub IGBT 12b. The sub-IGBT 12b is a semiconductor element capable of high-power high-speed switching, and functions as sub-switch means for switching energization / cut-off to the sub-primary coil 111b based on the sub-primary coil superimposed signal Sb from the ignition control means 13. To do.
The main primary coil 111a and the sub primary coil 111b are wound around a bobbin inserted into the outer periphery of the center core 113, and are wound so that the direction of the magnetic flux generated when the DC power supply 4 is energized is reversed. Make the turning direction or feeding position different. For example, as shown in FIG. 2, when power is supplied from the same side (lower part in FIG. 2), the winding direction of the main primary coil 111a and the winding direction of the sub-primary coil 111b are reversed.
First, when the main IGBT 12a is turned on and the primary current I1a flows through the main primary coil 111a, a magnetic flux is generated (see FIG. 2A). Assuming that the direction of the energized magnetic flux is the positive direction, when the IGBT 12a is turned off and the primary current I1a is interrupted, a reverse interrupting magnetic flux is generated (see FIG. 2B). This breaking magnetic flux acts on the secondary coil 1112 to generate discharge energy that causes dielectric breakdown in the discharge gap of the spark plug 2.
Furthermore, when the sub-IGBT 12b is turned on after the shut-off timing at which the energization to the main primary coil 111a is cut off and the superimposed current I1b flows through the sub-primary coil 111b, a superimposed magnetic flux in the same direction as the interrupted magnetic flux is generated (FIG. 2). (See (c)). That is, when the interrupting magnetic flux and the superimposed magnetic flux act on the secondary coil 112, the discharge energy generated in the secondary coil 112 can be increased in a superimposed manner.
In addition, the number of turns of the sub primary coil 111b is set so that the voltage generated in the sub primary coil 111b due to the magnetic flux change when the energization to the main primary coil 111a is cut off becomes smaller than the power supply voltage (for example, + 12V). It is necessary to keep. For example, when the voltage generated in the secondary primary coil 111b when the energization to the primary primary coil 111a is cut off is larger than the voltage of the DC power supply 4, the superimposed magnetic flux is generated even if the secondary IGBT 12b is turned on. This is because the superimposed current I1b cannot flow.
Further, when the sub-IGBT 12b is turned off and the energization to the sub-primary coil 111b is cut off, the counter electromotive force acts on the main primary coil 111a, so that a current in the direction opposite to the normal primary current is caused to flow. A reverse voltage is applied between the emitter and the collector of the main IGBT 12a, and there is a risk that the main IGBT 12a may break down or the deterioration of the main IGBT 12a may be accelerated. Therefore, a bypass line 14 is provided in parallel with the main IGBT 12a, and a rectifier 15 (for example, a cathode is connected to the collector side of the main IGBT 12a in the forward direction from the ground point side of the bypass line 14 toward the ignition coil 11 side. A diode having an anode connected to the emitter side of the IGBT 12a was provided.
Next, the operation of the ignition coil unit 10 by the main primary coil ignition signal Sa and the sub primary coil superimposed signal Sb generated by the ignition control means 31 will be described based on the waveform diagram of FIG.
The ignition control means 31 performs normal discharge control in an operating situation in which appropriate discharge characteristics are obtained only by the main primary coil 111a without adding a superimposed magnetic flux to the interrupting magnetic flux.
First, the signal level of the main primary coil ignition signal Sa is changed from L to H at an appropriate timing of the discharge cycle, the main IGBT 12a is turned on, and the primary current I1a starts to flow. At the timing when the primary current energization time Ta has passed, the signal level of the main primary coil ignition signal Sa is changed from H to L, the main IGBT 12a is turned off, the primary current I1a is cut off, and the secondary coil 112 side is turned on. A current I2 is supplied. During this time, the signal level of the sub-primary coil superimposed signal Sb is maintained at L, the sub-IGBT 12b remains off, and the superimposed current I1b does not flow through the sub-primary coil 111b, so that the superimposed magnetic flux acts on the secondary coil 112. There is nothing.
In the case of an operating situation that requires a large amount of discharge energy at the beginning of the discharge start, the ignition control means 31 performs a high current type superimposed discharge control.
After starting the primary current I1a in the same manner as the normal discharge control described above, the signal level of the main primary coil ignition signal Sa is changed from H to L at the timing when the primary current energization time Ta has passed, and the main IGBT 12a is turned off. At the same time, the signal level of the sub primary coil superimposed signal Sb is changed from L to H, the sub IGBT 12b is turned on, and the primary current I1b is supplied. As a result, a superimposed magnetic flux generated by energizing the sub primary coil 111b is added at a timing immediately after the start of discharge at which the interrupting magnetic flux generated by interrupting the energization of the main primary coil 111a is maximized, and the initial secondary current I2 Becomes a high current. Thereafter, the signal level of the sub primary coil superimposed signal Sb is changed from H to L at the timing when the superposed current energizing time Tb determined taking into account the time necessary for discharging the spark plug 2 has elapsed, and the sub IGBT 12b is turned off. The superimposed current I1b is cut off.
In an operating situation where it is necessary to maintain a certain level or more of discharge energy for a relatively long time from the start of discharge, the ignition control means 31 performs long discharge type superimposed discharge control.
Similar to the normal discharge control described above, after the primary current I1a starts to flow, the primary current energization time Ta elapses, the main IGBT 12a is turned off, the primary current I1a is cut off, and the secondary current I2 is supplied to the secondary coil 112 side. However, the signal level of the sub primary coil superimposed signal Sb remains L. Thereafter, the signal level of the sub primary coil superposition signal Sb is changed from L to H at the timing when the superposition start delay time Δt determined in consideration of the time during which the secondary current I2 is maintained at a predetermined value or more. The secondary IGBT 12b is turned on, and the primary current I1b is supplied. As a result, the time until the secondary current I2 becomes higher again and the secondary current I2 becomes lower than a predetermined value (energy required for discharging the spark plug 2 is lost) can be extended. The discharge period can be kept long. Thereafter, the signal level of the sub primary coil superimposed signal Sb is changed from H to L at the timing when the superposed current energizing time Tb determined taking into account the time necessary for discharging the spark plug 2 has elapsed, and the sub IGBT 12b is turned off. The superimposed current I1b is cut off.
As described above, in the internal combustion engine ignition device 1 according to the present embodiment, the engine control unit 3 having the function of the ignition control means 31 performs the energization start timing and energization time of the sub-primary coil 111b based on the driving situation of the vehicle. Is generated, and the secondary primary coil superimposed signal Sb is generated accordingly to turn on / off the secondary IGBT 12b, thereby realizing the ignition control capable of obtaining the discharge characteristics suitable for the driving situation at that time.
As the information used for the determination of the driving situation, any information may be used as long as the information is related to the combustion of the cylinder, such as the engine speed, the secondary current value, the temperature of the ignition coil 11, and the like. Further, how to determine the energization start timing and energization time of the sub-primary coil 111b from the determination result of the operating situation belongs to know-how according to the engine characteristics, etc. The energization start timing and energization time of the sub primary coil 111b are not uniquely determined.
In the internal combustion engine ignition device 1 according to the first embodiment described above, since the ignition control means 31 is provided in the engine control unit 3, it is necessary for determining energization / cutoff control of the main primary coil 111a and the sub primary coil 111b. While it is easy to grasp the driving situation, the primary primary coil ignition signal Sa and the secondary primary coil superimposed signal Sb must be supplied to the ignition coil units 10 of all the cylinders. Compatibility is lost, and the function added to the engine control unit 3 becomes complicated.
An internal combustion engine ignition device 1 ′ according to the second embodiment that can maintain compatibility with the existing engine control unit 3 will be described with reference to FIG. 4. In addition, the same code | symbol is attached | subjected to the structure of the same and same function as the internal combustion engine ignition device 1 of 1st Embodiment, and description is abbreviate | omitted.
The internal combustion engine ignition device 1 ′ is provided with ignition control means 5 corresponding to the ignition coil unit 10 ′ of each cylinder, separately from the engine control unit 3, and receives an ignition signal S from the engine control unit 3. The control means 5 controls the operation of the ignition coil unit 10 '. That is, in the internal combustion engine ignition device 1 ′ of the present embodiment, if the existing engine control unit 3 transmits an ignition signal S including information on the ignition timing and charging time in each combustion cycle, the ignition control means that has received the ignition signal S 5 generates the primary primary coil ignition signal Sa and the secondary primary coil superimposed signal Sb, and the on / off control of the primary IGBT 12a and the secondary IGBT 12b is performed to realize appropriate superimposed discharge control.
As information for the ignition control means 5 to grasp the driving situation, there is an engine speed based on the cycle of the ignition signal S transmitted from the engine control unit 3, and therefore, the energization start timing and energization of the sub primary coil 111b. The time may be controlled in association with only the engine speed, but a state unique to each cylinder may be acquired to appropriately control the energization start timing and energization time of the sub primary coil 111b. .
For example, the ignition coil unit 10 ′ is provided with secondary current detection means 16 for detecting the secondary current I 2, and the ignition control means 5 starts the energization start timing of the sub primary coil 111 b based on this secondary current detection signal. Alternatively, the energization time may be determined. Further, a temperature sensor 17 is provided at an appropriate position in the case 13 of the ignition coil unit 10 ', and the ignition control means 5 is connected to the sub primary coil 111b based on the internal temperature due to heat generated from the ignition coil 11, the main IGBT 12a, and the sub IGBT 12b. The energization start timing and energization time may be determined.
In the internal combustion

engine ignition devices

1, 1 ′ of the first and second embodiments described above, although the energization start timing and energization time of the sub primary coil 111 b can be arbitrarily controlled by the sub primary coil superimposed signal Sb, the sub primary coil Since the voltage applied to 111b is determined by the power supply voltage of the DC power supply 4, there is a possibility that unnecessary discharge energy is superimposed by the sub primary coil 111b, resulting in wasteful power consumption.
For example, if a power supply to the sub-primary coil 111b is separately provided and the supply voltage to the sub-primary coil 111b can be adjusted as necessary, it is necessary and sufficient discharge energy while suppressing excessive power consumption. Can be superimposed. However, in order to obtain such a configuration, a variable output type DC power source is required, and a power source mounting space must be secured in the vehicle body, and the cost is considerably increased.
Therefore, a method using pulse width modulation (PWM) control is conceivable in order to adjust the energization amount to the sub primary coil 111b using the DC power supply 4 mounted on the vehicle. That is, the sub-IGBT 12b is switched at high speed by PWM control, the on-duty is appropriately adjusted, and the substantial voltage applied to the sub-primary coil 111b is reduced to a necessary and sufficient level.
For example, in the internal combustion engine ignition device 1 shown in FIG. 1, if the sub-primary coil superimposed signal Sb ′ sent from the engine control unit 3 is a PWM signal, the sub-IGBT 12b can be PWM-controlled, and the power supply voltage (for example, , + 12V) is reduced to a desired real voltage, and the superimposed current I1b is arbitrarily adjusted to suppress the discharge energy applied to the secondary coil 112 by the superimposed magnetic flux.
FIG. 5 shows a waveform when the secondary IGBT 12b is PWM-controlled. When the superposed discharge is maximized, +12 V is supplied from the DC power supply 4 to the sub primary coil 111b by not performing the PWM control with the duty ratio of the sub primary coil superimposed signal Sb 'being 100%. Further, when necessary and sufficient discharge energy can be superimposed by applying a voltage of about +10 V to the sub primary coil 111b, the sub IGBT 12b may be PWM-controlled with a duty ratio of about 83%. Similarly, when necessary and sufficient discharge energy can be superimposed by applying a voltage of about +8 V to the sub primary coil 111b, the sub IGBT 12b may be PWM controlled with a duty ratio of about 67%. If necessary and sufficient discharge energy can be superimposed by applying a voltage of about +6 V, the sub-IGBT 12b may be PWM controlled with a duty ratio of about 50%.
Also for the PWM control for the sub-IGBT 12b, a necessary and sufficient applied voltage may be calculated based on the driving situation determined from various vehicle information, and the duty ratio of the sub-primary coil superimposed signal Sb ′ may be determined.
As described above, the engine control unit 3 and the ignition control means 5 of the internal combustion

engine ignition devices

1, 1 ′ of the first and second embodiments generate the sub-primary coil superimposed signal Sb ′ and the

ignition coil units

10, 10. When the secondary IGBT 12b is subjected to PWM control by transmitting to ', the secondary primary coil superimposed signal Sb' including a high frequency pulse becomes a noise source, or conversely, PWM control by the secondary primary coil superimposed signal Sb 'due to noise mixing. May not work as intended.
6 shows a schematic configuration of an ignition coil unit 10 ″ used for the internal combustion engine ignition device according to the third embodiment, and includes a PWM signal generation circuit 18 in the case 13. That is, the ignition coil unit. The PWM signal generation circuit 18 is added to the igniter circuit within 10 ″.
In order to generate a desired PWM signal by the PWM signal generation circuit 18, in addition to an information signal for specifying the energization start timing and energization time of the sub primary coil 111b, an information signal for instructing a duty ratio of PWM control Is also necessary. Therefore, the engine control unit 3 and the ignition control means 5 provide a PWM instruction signal Sb2 for instructing the duty ratio of PWM control in addition to the sub primary coil superimposed signal Sb1 for specifying the energization start timing and energization time of the sub primary coil 111b. Send.
The PWM instruction signal Sb2 may be one that transmits numerical information of the duty ratio. However, in the PWM instruction signal Sb2 in this embodiment, the level is divided according to the signal potential of the transmission signal, and this level is the duty of the PWM control. Information to show the ratio. As described above, the function of determining the level by filtering the PWM instruction signal Sb2 with a predetermined threshold value can be easily configured with discrete parts having high heat resistance and high noise resistance. If the PWM signal generation circuit 18 composed of discrete components is provided in the igniter circuit, the risk of the PWM signal generation circuit 18 malfunctioning or damaging due to thermal runaway can be reduced, so that the reliability of PWM control is improved. There is no loss.
FIG. 7 is a waveform diagram when ignition control is performed by the ignition coil unit 10 ″. If the signal potential of the PWM instruction signal Sb2 reaches the maximum value, it is determined as level 4 and the PWM signal Since the duty ratio is set to 100% and PWM control is not performed, +12 V is supplied from the DC power supply 4 to the sub primary coil 111b, and if the signal potential of the PWM instruction signal Sb2 is determined to be level 3 lower than level 4. The PWM signal is generated with a duty ratio of about 83%, and the sub-IGBT 12b is PWM-controlled, and if the signal potential of the PWM instruction signal Sb2 is determined to be level 2 lower than level 3, the PWM is driven with a duty ratio of about 67%. A signal is generated, and the sub-IGBT 12b is PWM-controlled.If the signal potential of the PWM instruction signal Sb2 is determined to be level 1 lower than level 2, A PWM signal is generated at a duty ratio of 50%, and the secondary IGBT 12b is PWM-controlled, and if the signal potential of the PWM instruction signal Sb2 is determined to be level 0 equal to the ground potential, the duty ratio of the PWM signal is set to 0%. The PWM control of the secondary IGBT 12b is not performed.
The above-described level division of the PWM instruction signal Sb2 is an example, and it may be divided into a smaller number of levels and correspond to the duty ratio of the PWM signal, or may be divided into a larger number of levels and correspond to the duty ratio of the PWM signal. Also good.
As described above, in the internal combustion engine ignition device according to the first to third embodiments, one ignition coil 11 including the main primary coil 111a and the sub primary coil 111b is provided, and the energization timing and energization to the sub primary coil 111b are provided. By controlling the time appropriately and further adjusting the voltage applied to the sub-primary coil 111b, the discharge energy applied to the secondary coil 112 is controlled, and the high current type superimposition is realized so as to realize the optimum discharge characteristics. Discharge control and long discharge type superimposed discharge control are possible.
Conventionally, each ignition coil was separately made up of a high current type coil and a long discharge type coil, so when using a high current type coil, the discharge time is shortened, and when using a long discharge type coil Has a characteristic limitation that the current cannot be increased. In the past, when it was desired to change the discharge performance, it was necessary to replace the ignition coil. In the internal combustion engine ignition device according to the first to third embodiments, the energization / cutoff control to the sub-primary coil 111b was performed. Various types of discharge performance can be realized.
However, also in the internal combustion engine ignition device according to the first to third embodiments, there is a limit to the increase in current and the length of discharge that can be realized by energization / cutoff control to the sub-primary coil 111b.
FIG. 8 shows a schematic configuration of an ignition coil unit 20A used in the internal combustion engine ignition device according to the fourth embodiment. By using a plurality of ignition coils, a higher current and a longer discharge are shown. It can be expected.
In the ignition coil unit 20A, the first ignition coil portion 21 and the second ignition coil portion 22 are housed in a case 23, and the ignition plug 2 is connected via the high voltage terminal 231, and the first connector 232 and the second connector 233 are connected. To the engine control unit 3 or the ignition control means 5.
The first ignition coil unit 21 includes a first ignition coil 211, a first main IGBT 212a, a first sub-IGBT 212b, a bypass line 214 provided in parallel with the first main IGBT 212a, and a first ignition coil from the ground point side of the bypass line 214. Rectifying means 215 (for example, a diode having a cathode connected to the collector side of the first main IGBT 212a and an anode connected to the emitter side of the first main IGBT 212a) provided so as to be in the forward direction toward the 211 side; The first main primary coil ignition signal Sa-1 and the first sub primary coil superimposed signal Sb-1 are supplied via the connector 232.
The second ignition coil unit 22 includes a second ignition coil 221, a second main IGBT 222a, a second sub-IGBT 222b, a bypass line 224 provided in parallel with the second main IGBT 222a, and a second from the ground point side of the bypass line 224. Rectifying means 225 (for example, a diode having a cathode connected to the collector side of the second main IGBT 222a and an anode connected to the emitter side of the second main IGBT 222a) provided so as to be in the forward direction toward the ignition coil 221 side, The second main primary coil ignition signal Sa-2 and the second sub primary coil superimposed signal Sb-2 are supplied via the second connector 233.
In addition, the 1st ignition coil 211 and the 2nd ignition coil 221 are the structures similar to the ignition coil 11 mentioned above. That is, the magnetic flux generated in the first main primary coil 2111a and the first sub primary coil 2111b inserted into the outer periphery of the center core 2113 is applied to the first secondary coil 2112, and the first main coil 2111b inserted into the outer periphery of the center core 2213 is inserted. Magnetic flux generated in the two main primary coils 2211a and the second sub primary coil 2211b is applied to the second secondary coil 2212. Further, the non-grounded side of the first secondary coil 2112 of the first ignition coil 211 and the non-grounded side of the second secondary coil 2212 of the second ignition coil 221 are connected in parallel to the spark plug 2.
FIG. 9 shows waveforms when the discharge control is performed so as to realize various types of discharge performance in the ignition coil unit 20A configured as described above.
First, in the case of an operation situation that requires a large amount of discharge energy from the beginning to the middle of the start of discharge, the engine control unit 3 or the ignition control means 5 performs the following medium-term high current type superimposed discharge control.
The first main IGBT 212a and the second main IGBT 222a are turned on almost simultaneously by the first main primary coil ignition signal Sa-1 and the second main primary coil ignition signal Sa-2.
After starting the first coil primary current I1a-1 and the second coil primary current I1a-2, the signal of the first main primary coil ignition signal Sa-1 at the timing when the first coil primary current energization time Ta-1 has passed. The level is changed from H to L, and the first main IGBT 212a is turned off. Thereby, the interruption | blocking magnetic flux produced by the interruption | blocking of electricity supply to the 1st main primary coil 2111a acts on the 1st secondary coil 2112, and the 1st coil secondary current I2-1 flows.
The signal level of the second main primary coil ignition signal Sa-2 is changed from H to L at the timing when the second coil primary current energization time Ta-2 set at the same time as the first coil primary current energization time Ta-1 has elapsed. To turn off the second main IGBT 222a. Thereby, the interruption | blocking magnetic flux produced by the electricity supply interruption | blocking to the 2nd main primary coil 2211a acts on the 2nd secondary coil 2212, and the 2nd coil secondary current I2-2 flows.
That is, when the first main primary coil 2111a and the second main primary coil 2211a are energized at the same time, the first coil secondary current I2-1 and the second ignition coil portion flowing to the first ignition coil portion 21 side are cut off. As the ignition coil unit secondary current I2, which is equal to the sum of the second coil secondary current I2-2 flowing on the 22 side, a large current flows in the initial discharge.
Thereafter, at the timing when the first superposition start delay time Δt-1 determined in consideration of the time during which the ignition coil unit secondary current I2 is maintained at a predetermined value or more, the first sub primary coil superposition signal Sb-1 , The first sub-IGBT 212b is turned on, and the first coil superimposed current I1b-1 is supplied. Thereby, the first coil secondary current I2-1 becomes high again.
Further, the signal level of the second sub-primary coil superposition signal Sb-2 is changed from L to H at the timing when the second superposition start delay time Δt-2 set at the same time as the first superposition start delay time Δt-1 has elapsed. The second sub-IGBT 222b is turned on and the second coil superimposed current I1b-2 is supplied. Thereby, the 2nd coil secondary current I2-2 becomes high again.
That is, when the first sub primary coil 2111b and the second sub primary coil 2211b are energized simultaneously, the first coil secondary current I2-1 flowing to the first ignition coil unit 21 side and the second ignition coil unit 22 side As the ignition coil unit secondary current I2, which is equal to the sum of the second coil secondary current I2-2 flowing through the large current, a large current flows again in the middle of the discharge. In addition, the first coil superimposed current I1b-1 and the second coil superimposed current I1b-2 are passed while the interrupted magnetic flux generated by the current interruption to the first main primary coil 2111a and the second main primary coil 2211a is strong. By adding, a secondary current higher than that immediately after the start of discharge can flow in the first to middle stages of discharge.
Thereafter, at the timing when the superimposed current energization time (first superimposed current energization time Tb-1 = second superimposed current energization time Tb-2) determined in consideration of the time necessary and sufficient for discharging the spark plug 2 has passed. The first sub-IGBT 212b and the second sub-IGBT 222b are turned off at the same time by changing the signal levels of the first sub-primary coil superimposed signal Sb-1 and the second sub-primary coil superimposed signal Sb-2 from H to L at the same time. The superimposed current I1b-1 and the second coil superimposed current I1b-2 are simultaneously cut off.
If the control for starting energization to the first sub primary coil 2111b and the second sub primary coil 2211b at the same time as the energization interruption to the first main primary coil 2111a and the second main primary coil 2211a is performed, the initial stage of discharge Although the highest secondary current can flow, the high current cannot be maintained from the middle period to the latter period.
Therefore, in an operating situation where it is necessary to maintain a certain amount of discharge energy from the initial period to the middle period immediately after the start of discharge, the engine control unit 3 or the ignition control means 5 performs the following high current + long discharge. Perform type of superimposed discharge control.
The first main IGBT 212a and the second main IGBT 222a are turned on almost simultaneously by the first main primary coil ignition signal Sa-1 and the second main primary coil ignition signal Sa-2.
After starting to flow the first coil primary current I1a-1 and the second coil primary current I1a-2, the primary current energization time (first coil primary current energization time Ta-1 = second coil primary current energization time Ta-2). The signal levels of the first main primary coil ignition signal Sa-1 and the second main primary coil ignition signal Sa-2 are changed from H to L at the same time, and the first main IGBT 212a and the second main IGBT 222a are simultaneously changed. Turn off. Thereby, the interruption | blocking magnetic flux produced by the energization interruption | blocking to the 1st main primary coil 2111a and the 2nd main primary coil 2211a acts on the 1st secondary coil 2112 and the 2nd secondary coil 2212, respectively, and the 1st coil secondary current I2-1 and second coil secondary current I2-2 flow.
That is, when the first main primary coil 2111a and the second main primary coil 2211a are energized at the same time, the first coil secondary current I2-1 and the second ignition coil portion flowing to the first ignition coil portion 21 side are cut off. As the ignition coil unit secondary current I2, which is equal to the sum of the second coil secondary current I2-2 flowing on the 22 side, a large current flows in the initial discharge.
Thereafter, at the timing when the first superposition start delay time Δt-1 determined in consideration of the time during which the ignition coil unit secondary current I2 is maintained at a predetermined value or more, the first sub primary coil superposition signal Sb-1 , The first sub-IGBT 212b is turned on, and the first coil superimposed current I1b-1 is supplied. As a result, the ignition coil unit secondary current I2 becomes high again at the timing when the first superposition start delay time Δt−1 has elapsed since the energization of the first main primary coil 2111a and the second main primary coil 2211a was cut off.
Furthermore, the second superposition start delay time Δt−2 (the ignition coil unit secondary current I2 that has been increased by the first coil superposition current I1b-1 holds a predetermined value or more after the energization of the second main primary coil 2211a is cut off) The signal level of the second sub-primary coil superimposed signal Sb-2 is changed from L to H at the timing when “Δt−2> Δt−1” is satisfied. Then, the second auxiliary IGBT 222b is turned on, and the second coil superimposed current I1b-2 is supplied. As a result, the ignition coil unit secondary current I2 becomes high again at the timing when the second superposition start delay time Δt-2 has elapsed from the interruption of energization to the first main primary coil 2111a and the second main primary coil 2211a.
Thereafter, at the timing when the first superimposed current energization time Tb-1 has elapsed, the signal level of the first sub primary coil superimposed signal Sb-1 is changed from H to L, the first sub IGBT 212b is turned off, and the first coil By interrupting the superimposed current I1b-1, the first coil secondary current I2-1 is interrupted, and then, at the timing when the second superimposed current energization time Tb-2 has elapsed, the second sub primary coil superimposed signal Sb -2 is changed from H to L, the second sub-IGBT 222b is turned off, the second coil superimposed current I1b-2 is cut off, the second coil secondary current I2-2 is cut off, and the ignition The coil unit secondary current I2 stops flowing.
In other words, the first coil superimposed current I1b-1 is caused to flow at the timing when the first superimposition start delay time Δt-1 has elapsed since the energization of the first main primary coil 2111a and the second main primary coil 2211a is cut off, and the second superposition start delay By causing the second coil superimposed current I1b-2 to flow at the timing when the time Δt-2 has passed and increasing the current value of the ignition coil unit secondary current I2 by a time difference, a certain degree from the initial period to the middle period immediately after the start of discharge. The discharge energy of the magnitude of can be maintained.
Note that if the time width of the first superimposed current energizing time Tb-1 and the second superimposed current energizing time Tb-2 is set longer, the discharge time can be further increased, but the first main primary coil 2111a and the second If the interruption magnetic flux generated by the interruption of energization to the main primary coil 2211a disappears, sufficient discharge energy cannot be maintained only by the first coil superimposed current I1b-1 and the second coil superimposed current I1b-2, and the discharge time There is also a limit to how long it can be.
Therefore, in the case of an operating situation in which a very high current is not required during the discharge period, but it is necessary to maintain a certain amount of discharge energy from the initial period immediately after the start of discharge to the intermediate period to the latter period, the engine control unit 3 or The ignition control means 5 performs the following high current + long discharge type superimposed discharge control.
In response to the first main primary coil ignition signal Sa-1, the first main IGBT 212a is turned on, the first coil primary current I1a-1 starts to flow, and then the second ignition coil operation delay time ΔT has passed. The second primary IGBT 222a is turned on by the main primary coil ignition signal Sa-2, and the first coil primary current I1a-1 starts to flow.
The signal level of the first main primary coil ignition signal Sa-1 is changed from H to L at the timing when the first coil primary current energization time Ta-1 has passed after the first coil primary current I1a-1 starts to flow, The first main IGBT 212a is turned off. Thereby, the interruption | blocking magnetic flux produced by the interruption | blocking of electricity supply to the 1st main primary coil 2111a acts on the 1st secondary coil 2112, and the 1st coil secondary current I2-1 flows. A current equal to the first coil secondary current I2-1 flows as the ignition coil unit secondary current I2.
Thereafter, at the timing when the first superposition start delay time Δt-1 determined in consideration of the time during which the ignition coil unit secondary current I2 is maintained at a predetermined value or more, the first sub primary coil superposition signal Sb-1 The first sub-IGBT 212b is turned on, the first coil superimposed current I1b-1 is supplied, and the first coil secondary current I2-1 is increased. As a result, the ignition coil unit secondary current I2 also increases again at the timing when the first superposition start delay time Δt−1 has elapsed since the energization of the first main primary coil 2111a was cut off.
On the other hand, after the second coil primary current I1a-2 starts to flow, the signal level of the second main primary coil ignition signal Sa-2 is changed from H to L at the timing when the second coil primary current energization time Ta-2 has elapsed. Then, the second main IGBT 222a is turned off. Thereby, the interruption | blocking magnetic flux which arises by the electricity supply interruption | blocking to the 2nd main primary coil 2211a acts on the 2nd secondary coil 2212, and the 2nd coil secondary current I2-2 flows. The second coil secondary current I2-2 is superimposed on the first coil secondary current I2-1, and the ignition coil unit secondary current I2 becomes high again.
Thereafter, at the timing when the second superposition start delay time Δt-2 determined in consideration of the time during which the ignition coil unit secondary current I2 is maintained at a predetermined value or more, the second sub primary coil superposition signal Sb-2 , The second sub-IGBT 222b is turned on, the second coil superimposed current I1b-2 is supplied, and the second coil secondary current I2-2 is increased. Thereby, the ignition coil unit secondary current I2 becomes high again.
Thereafter, at the timing when the first superimposed current energization time Tb-1 has elapsed, the signal level of the first sub primary coil superimposed signal Sb-1 is changed from H to L, the first sub IGBT 212b is turned off, and the first coil By interrupting the superimposed current I1b-1, the first coil secondary current I2-1 is interrupted, and then, at the timing when the second superimposed current energization time Tb-2 has elapsed, the second sub primary coil superimposed signal Sb -2 is changed from H to L, the second sub-IGBT 222b is turned off, the second coil superimposed current I1b-2 is cut off, the second coil secondary current I2-2 is cut off, and the ignition The coil unit secondary current I2 stops flowing.
That is, there is a time difference between the energization interruption to the first main primary coil 2111a, the energization start to the first sub primary coil 2111b, the energization interruption to the second main primary coil 2211a, and the energization start to the second sub primary coil 2211b. By increasing the current value of the ignition coil unit secondary current I2 with a time difference, it is possible to perform a long discharge while maintaining a certain amount of discharge energy from the initial period immediately after the start of discharge to the middle period to the latter period.
Thus, various discharge patterns can be realized by using a plurality of ignition coils and appropriately controlling the operation timing. In particular, since it is easy to shift the arrangement of high current from the previous period to the middle period, there is a high possibility that discharge patterns suitable for future engines such as high EGR combustion, high compression ratio combustion, and lean burn combustion can be easily realized. High practical value.
Note that the number of ignition coils controlled by the main primary coil ignition signal and the sub-primary coil superimposed signal as described above is not limited to two, and three or more ignition coils may be used if storage space permits. If the number of ignition coils increases, it becomes possible to selectively use more detailed discharge patterns. Further, the connection method of the plurality of ignition coils is not limited to parallel connection, and may be connected in series.
FIG. 10 shows a schematic configuration of an ignition coil unit 20B used in the internal combustion engine ignition device according to the fifth embodiment. The first secondary coil 2112 and the second ignition coil of the first ignition coil unit 21 are shown. The second secondary coil 2212 of the unit 22 is connected in series.
The ignition coil unit 20B includes a first ignition coil portion 21 and a second ignition coil portion 22 housed in a case 23, and is connected to the engine control unit 3 or the ignition control means 5 via a common connector 234. In response to the main primary coil ignition signal Sa-1, the first sub primary coil superimposed signal Sb-1, the second main primary coil ignition signal Sa-2, and the second sub primary coil superimposed signal Sb-2, the first main primary coil 2111a is received. The first sub primary coil 2111b, the second main primary coil 2211a, and the second sub primary coil 2211b are controlled to be energized and cut off.
In the ignition coil unit 20B, the first secondary coil 2112 of the first ignition coil 211 and the second secondary coil 2212 of the second ignition coil 221 are connected in series. During operation, the discharge energy generated by the first ignition coil 221 is consumed by the resistance of the second ignition coil 221, which may impair the ignitability of the spark plug 2. Therefore, the rectifying element 25 (series connection) is connected to the ground line 24 from the series connection point where the first secondary coil 2112 of the first ignition coil 211 and the second secondary coil 2212 of the second ignition coil 221 are connected to the ground point. An anode is connected to the series connection point side and a cathode is connected to the ground point side so that the forward direction is from the point toward the ground point.
As mentioned above, although embodiment of the ignition device for internal combustion engines which concerns on this invention was described based on the accompanying drawing, this invention is not limited to these embodiment, The structure as described in a claim is changed. As long as it is not, it may be carried out by diverting known equivalent technical means.

DESCRIPTION OF SYMBOLS 1 Ignition device 10 for internal combustion engines Ignition coil unit 11 Ignition coil 111a Main primary coil 111b Sub primary coil 112 Secondary coil 113 Center core 12a Main IGBT
12b Deputy IGBT
13 Case 2 Spark plug 3 Engine control unit 31 Ignition control means 4 DC power supply

Claims

A primary primary coil that generates an energized magnetic flux in the forward direction when energized and a reverse interrupted magnetic flux when the current is interrupted, a sub-primary coil that generates an additional magnetic flux in the same direction as the interrupted magnetic flux when energized, and an ignition plug on one end side An ignition coil having a secondary coil that is connected to the main primary coil and the secondary primary coil to generate discharge energy by the magnetic flux generated in the primary primary coil and the secondary primary coil,
Main switch means for switching energization / cutoff to the main primary coil of the ignition coil;
Sub-switch means for switching energization / cut-off to the sub-primary coil of the ignition coil;
Ignition control means for controlling the switching operation of the main switch means and the sub switch means to generate a discharge spark in the spark plug at a predetermined timing of the combustion cycle;
With
The ignition control means increases the discharge energy generated in the secondary coil in a superimposed manner by energizing the sub-primary coil for a predetermined superimposition time after the shut-off timing when the energization to the main primary coil is shut off. An internal combustion engine ignition device.
2. The ignition device for an internal combustion engine according to claim 1, wherein a single direct current power source is shared for power supply to the main ignition coil and the sub ignition coil of the ignition coil.
The number of turns of the sub primary coil is set so that a voltage generated in the sub primary coil due to a change in magnetic flux when the energization to the main primary coil is cut off becomes smaller than a power supply voltage. Item 3. The ignition device for an internal combustion engine according to Item 2.
The bypass line connected in parallel with the main switch means connected between the main ignition coil and the ground point is provided with a rectifying means that is forward from the ground point side toward the ignition coil side. The ignition device for an internal combustion engine according to any one of claims 1 to 3.
The internal combustion engine ignition according to any one of claims 1 to 4, wherein the ignition control means determines the energization start timing of the auxiliary ignition coil based on a driving situation of the vehicle. apparatus.
6. The ignition device for an internal combustion engine according to claim 1, wherein the ignition control means determines the energization time of the auxiliary ignition coil based on a driving situation of the vehicle. .
The sub-switch means has a high-speed switching characteristic that can sufficiently follow an input short pulse,
The internal combustion engine according to any one of claims 1 to 6, wherein the ignition control means performs PWM control of the sub switch means with a pulse signal having a duty ratio determined based on a driving situation of the vehicle. Engine ignition device.
Providing a secondary current detecting means for detecting a secondary current flowing on the secondary side of the ignition coil;
The ignition device for an internal combustion engine according to claim 5 or 6, wherein the ignition control means determines a driving state of the vehicle based on the secondary current detected by the secondary current detection means. .
A plurality of ignition coils, and main switch means and sub switch means corresponding to each ignition coil,
Connect the secondary coil in all ignition coils in parallel to the spark plug,
The internal combustion engine according to any one of claims 1 to 8, wherein the ignition control means controls energization / cutoff of the main primary coil and the sub primary coil in all ignition coils. Engine ignition device.
A plurality of ignition coils, and main switch means and sub switch means corresponding to each ignition coil,
Connect the secondary coil in all ignition coils in series with the spark plug,
The internal combustion engine according to any one of claims 1 to 8, wherein the ignition control means controls energization / cutoff of the main primary coil and the sub primary coil in all ignition coils. Engine ignition device.
2. The ignition control means is incorporated in an internal combustion engine drive control device that comprehensively controls the operation of the internal combustion engine, and the internal combustion engine drive control device performs ignition control of all cylinders. The ignition device for an internal combustion engine according to any one of claims 10 to 10.
The ignition control means is provided for each cylinder, and performs ignition control of the corresponding cylinder based on an ignition instruction from an internal combustion engine drive control device that comprehensively controls the operation of the internal combustion engine. The internal combustion engine ignition device according to any one of claims 1 to 10.
13. The unit according to claim 1, wherein at least the ignition coil and main switch means and sub switch means provided corresponding to the ignition coil are housed in a single case. The ignition device for internal combustion engines of any one of these.