JP6078432B2 - Ignition device for internal combustion engine and ignition control device used therefor - Google Patents

Description

  The present invention relates to an ignition device for an internal combustion engine having a failure detection function of each part when performing ignition control for extending the spark discharge time from the ignition plug of the internal combustion engine by overlapping discharge, and an ignition control device used therefor, and It relates to a discharge unit.

  In recent years, reducing the fuel consumption of an internal combustion engine has become an important issue, and by utilizing the fact that pumping loss is reduced by the introduction of EGR (Exhaust Gas Recirculation) gas, driving at light loads for the purpose of reducing fuel consumption. In the area, there are increasing cases of adopting a technique for improving fuel efficiency by introducing a large amount of EGR gas. However, in such a case, as the ratio of new air introduced into the cylinder of the internal combustion engine decreases due to the increase of the inert gas, the ratio of the proper mixture around the spark plug is increased. Therefore, it is difficult to reliably ignite and obtain stable combustion with a single-hour discharge, and the internal combustion engine lacks stability due to incorrect combustion.

  Therefore, in the ignition device for an internal combustion engine, there is a variation in the state of the air-fuel mixture in the vicinity of the spark plug, so that in a state where a lean air-fuel ratio or an inert gas such as EGR gas is mixed, A technique for improving the fuel efficiency of an internal combustion engine by improving the problem that the ignitability of the air-fuel mixture is not stabilized by time discharge and improving the ignitability and stable combustion is regarded as important. As such a well-known technique, for example, “overlap discharge ignition device for internal combustion engine” (Patent Document 1) can be cited. Further, as a well-known technique for detecting the combustion state of the air-fuel mixture in the cylinder of the internal combustion engine, there is a “misfire detection circuit for internal combustion engine” (Patent Document 2) that detects misfire by detecting an ionic current in the combustion chamber of the internal combustion engine. Can be mentioned.

JP 2000-240542 A Japanese Patent No. 3192541

  According to the ignition control of the multiple discharge ignition device according to Patent Document 1 described above, since it is necessary to supply a large discharge energy to the spark plug for a long time, a predetermined voltage (for example, a booster circuit provided separately) 500 V) or more must be applied to the discharge current of the ignition coil, which increases the configuration of a booster circuit that can cover the number of cylinders in a multi-cylinder internal combustion engine, which causes mounting problems and is difficult to apply. There's a problem.

  In addition, since heat generation due to boosting occurs, it is necessary to install and dissipate heat in a place with a high cooling effect on mounting, and in a multi-cylinder internal combustion engine, it is desirable to configure the discharge unit separately on mounting. However, in the case where the discharge unit is a separate unit, if the entire region is overlapped for the control of the overlap discharge time, the current consumption becomes excessive, which may lead to problems such as deterioration or rise of the battery on which the vehicle is mounted. Therefore, it is desirable that the control unit side provides information on the overlap request signal for limiting the booster circuit for the purpose of limiting the use area of the overlap discharge.

  However, in the case of such a configuration, even if the technique of the cited document 2 is applied, if any part fails, it does not have a function to accurately determine that individually. There is a high possibility that the entire apparatus will be exchanged, and there is a problem that it is not possible to meet the demands on the dealer service for exchanging the failed part as much as possible. By the way, the technique of Cited Document 2 stores a part of the electric energy at the time of spark discharge in the cylinder, and can detect the combustion state (misfire) by the ion current value when the electric energy is applied to the electrode of the spark plug. Although it is a current detection circuit, it can accurately detect the failure of the ignition coil and spark plug as a failure of the ignition device, but other parts (for example, a discharge configured separately from the ignition coil and spark plug) There is a problem that a failure of a unit or a control unit cannot be determined accurately.

  The present invention has been made to solve such problems, and the technical problem thereof can be safely applied even to a multi-cylinder internal combustion engine in mounting, and the overdischarge is effectively performed to cause a problem in the battery. It is an object to provide an ignition device for an internal combustion engine, an ignition control device used therefor, and a discharge unit that can perform ignition control that is not allowed to occur, and can accurately determine a failure site even when a failure occurs.

  In order to solve the above technical problem, an internal combustion engine ignition device according to the present invention includes a plurality of spark plugs respectively disposed in the plurality of cylinders of the multiple cylinder internal combustion engine, and a plurality of spark plugs. A plurality of ignition coils for inducing a superimposed discharge output for causing spark discharge; an ignition control device for outputting an ignition control signal for controlling an ignition state in each of the plurality of cylinders with respect to the plurality of ignition coils; An ignition device for an internal combustion engine comprising a multiple discharge type discharge unit that performs multiple discharge for extending the time of spark discharge, wherein the ignition control device sends an ignition control signal to each of a plurality of ignition coils. A plurality of ignition signal control units that generate and control the ignition timing of the spark discharge, and an overlap request control signal that outputs the overlap request control signal for controlling the state of the overlap discharge to the discharge unit with one signal line A discharge control unit that switches the cylinders corresponding to the plurality of ignition coils in accordance with the ignition control signal and controls the time of the multiple discharge in accordance with the overlap request control signal. The multiple discharge boosted voltages are respectively applied to the plurality of ignition coils corresponding to the cylinders, and the plurality of ignition coils respectively input a primary current generated based on the ignition control signal and a predetermined constant voltage to the primary side. Then, an overlap discharge output is induced between the secondary side to which the boosted voltage is applied and corresponding ones of the plurality of spark plugs, and ions generated according to combustion in the corresponding cylinder at the time of the overlap discharge output Each has an ion detector that detects the current, and based on the result of measuring the rise timing of the ion current detected by the ion detector, the discharge accompanying the multiple discharge Characterized by comprising a discharge failure determination system overlaid determining a failure of the unit or the ignition control device.

  In addition, the ignition control device of the present invention induces an overlap discharge output for generating spark discharges with a plurality of spark plugs respectively disposed in the plurality of cylinders of the multi-cylinder internal combustion engine, An overlap discharge type discharge unit for performing overlap discharge for extending the time of the spark discharge in a plurality of ignition coils capable of detecting ion current generated in accordance with combustion in the corresponding cylinder at the time of the overlap discharge output; and An ignition control device that outputs an ignition control signal for controlling an ignition state in each of the plurality of cylinders to the plurality of ignition coils, and generates an ignition control signal for each of the plurality of ignition coils. A plurality of ignition signal control units for controlling the ignition timing of the spark discharge and an overlap request control signal for controlling the state of the overlap discharge for the discharge unit with one signal line Characterized by comprising the overlaid request signal controller for force, the.

The discharge unit is disposed in each of the plurality of cylinders in response to an ignition control signal output from an ignition control device for controlling an ignition state in the plurality of cylinders of the multi-cylinder internal combustion engine. A plurality of ignitions capable of inducing overlapping discharge outputs for generating spark discharges with a plurality of spark plugs and detecting ion currents generated in accordance with combustion in the corresponding cylinder at the time of the overlapping discharge outputs An overlap discharge type discharge unit that performs overlap discharge to extend the spark discharge time in the coil, and switches cylinders corresponding to a plurality of ignition coils in accordance with an ignition control signal and responds to an overlap request control signal It is possible to apply a boosted voltage for overlapping each discharge in the plurality of ignition coils corresponding to the switched-cylinder on which a controlled discharge time overlapped Te Masui.

  According to the lighting device for an internal combustion engine of the present invention, the ignition control device includes the overlap request signal control unit that outputs the overlap request control signal related to the request for overlap discharge with one signal line, and the overlap discharge type discharge unit is provided. The internal combustion engine is configured separately from the ignition coil and the ignition control device, and the cylinder corresponding to the ignition coil is switched by the discharge unit according to the ignition control signal from the ignition signal control unit in the ignition control device, and the overlap request signal After controlling the time of overlap discharge according to the overlap request control signal from the control unit, the boost voltage for overlap discharge is applied to the ignition coil corresponding to the switched cylinder, and the ignition coil is generated based on the ignition control signal The primary current and a predetermined constant voltage that are input on the primary side and the overlap discharge output is induced between the secondary side to which the boosted voltage is applied and the corresponding one of the spark plug. In order to determine the failure of the discharge unit or the ignition control device due to the multiple discharge based on the result of measuring the rising timing of the detected ion current by the multiple discharge failure determination device. In addition, it can be applied to multi-cylinder internal combustion engines without any problems in mounting, and it is possible to perform ignition control by effectively executing overlap discharge, increasing the degree of freedom in layout, and causing problems such as battery deterioration and rise. In addition, when a failure occurs, it becomes possible to accurately determine the failure site.

1 is a block diagram showing a basic configuration of an internal combustion engine ignition device according to Embodiment 1 of the present invention. FIG. FIG. 2 is a block diagram showing a detailed configuration of an overlapped discharge failure determination device mounted on a control unit of the internal combustion engine ignition device shown in FIG. 1. It is the figure which showed the basic composition of the ignition coil with which the ignition device for internal combustion engines shown in FIG. 1 is equipped including a response | compatibility with a discharge unit. FIG. 4 is a timing chart showing waveforms related to input / output of the ignition coil shown in FIG. 3. FIG. FIG. 3 is a flowchart showing an operation process for measuring rise timing of ion current by a rise time measuring unit in the overlapped discharge failure determination apparatus shown in FIG. 2. FIG. FIG. 3 is a flow chart showing an operation process from abnormality determination of overlap discharge to failure determination according to the overlap discharge abnormality determination unit, the overlap request control signal failure determination unit and the discharge unit failure determination unit in the overlap discharge failure determination apparatus shown in FIG. is there.

  Hereinafter, an ignition device for an internal combustion engine according to the present invention, an ignition control device used therefor, and a discharge unit will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a basic configuration of an internal combustion engine ignition device according to Embodiment 1 of the present invention. This internal combustion engine ignition device includes a plurality of ignition plugs 4a to 4d and a plurality of ignition plugs 4a to 4d respectively disposed in each cylinder of a four-cylinder internal combustion engine (engine) as a plurality of cylinders. Ion detection devices 320a to 320d that induce an overlap discharge output 401a to 401d for generating a spark discharge and detect an ion current generated in accordance with combustion in the corresponding cylinder at that time (however, 320b to 320d are shown in the figure). 4 for the ignition coils 3a to 3d provided with (not shown in FIG. 1), a multiple discharge type discharge unit 2 for performing multiple discharge for extending the spark discharge time, and each of the ignition coils 3a to 3d. An ignition control device 100 that outputs ignition control signals 101a to 101d for controlling the ignition state in each of the four cylinders is mounted to control the four cylinder internal combustion engine. At the same time, the multiple discharge failure determination device 500 that determines the failure of the discharge unit 2 or the ignition control device 100 associated with the multiple discharge based on the result of measuring the rising timing of the ion current detected by each of the ion detection devices 320a to 320d. And an engine control unit 1 mounted thereon.

  Among these, the ignition control device 100 generates ignition control signals 101a to 101d for the four ignition coils 3a to 3d, respectively, and controls ignition timing for four systems that controls the ignition timing of spark discharge in the cylinder. Unit 101 and an overlap request signal control unit 110 that outputs an overlap request control signal for controlling the state of overlap discharge to the discharge unit 2 with one signal line. Regarding the content of the overlap request related to the request control signal, the overlap operation region determination unit 112 that determines the operation region in the preset overlap discharge, and the preset overlap in the operation region determined by the overlap operation region determination unit 112 Overlap time determination unit 113 that determines the discharge time, and overlap switching determination unit that determines the execution region in the overdischarge in the operation region and switches from the non-execution region Configured to include the 11, the.

  Incidentally, the overlap request signal control unit 110 performs the overlap request related to the overlap request control signal according to the execution or stop of the overlap discharge determined by the overlap switching determination unit 111 and the overlap discharge time determined by the overlap time determination unit 113. Set the contents. Regarding the content of the overlap request, it is preferable that execution or stop of the overlap discharge and the time of the overlap discharge can be changed, and it is preferable that the overlap request is collectively transmitted to the discharge unit 2 with one signal information. In addition, the overlap request signal control unit 110 performs overlap discharge at the same time as or before the timing when the ignition signal control unit 101 starts to output the ignition control signals 101a to 101d to the ignition coils 3a to 3d. It is preferable to output an overlap request control signal related to execution. Furthermore, when the overlap switching determination unit 111 determines the transition from the non-execution region to the execution region in the overlap discharge, the overlap request content related to the overlap request control signal is overlapped before the control amount of the EGR gas amount increases. It is preferable to switch to performing discharge.

  The discharge unit 2 switches the cylinder corresponding to each of the ignition coils 3a to 3d in accordance with the ignition control signals 101a to 101d, and corresponds to the switched cylinder after controlling the time of the overlap discharge according to the overlap request control signal. The boosted voltages 203a to 203d are applied to the ignition coils 3a to 3d via the high voltage lines for overlapping discharge, respectively, and the ignition coils 3a to 3d, the ignition plugs 4a to 4d, and the ignition control device 100 are applied. Independent of the internal combustion engine. Specifically, the discharge unit 2 includes a cylinder switching circuit 201 that switches cylinders to be ignited according to the ignition control signals 101a to 101d input from the respective ignition signal control units 101, and the content of the overlap request related to the overlap request control signal. And a superposition time control circuit 202 for controlling the superposition discharge time in response to the superposition discharge voltage boosting voltages 203a to 203d applied to the ignition coils 3a to 3d corresponding to the cylinders switched in accordance with the superposition discharge time control. And a booster circuit 203 to be generated.

  The ignition coils 3a to 3d respectively generate a primary current and a predetermined constant voltage (+ 12V) generated by igniters 301a to 301d (note that 301b to 301d are not shown in FIG. 1) based on the ignition control signals 101a to 101d. Overlap discharge outputs 401a to 401d are induced from the secondary side to which the boosted voltages 203a to 203d are applied by the primary side and corresponding to each of the spark plugs 4a to 4d, and at the same time in the corresponding cylinder The ion current generated in response to the combustion of the gas is detected by the ion detectors 320 a to 320 d and sent to the overdischarge failure determination device 500 of the control unit 1.

  In the ignition device for an internal combustion engine shown in FIG. 1, in the ignition control device 100 mounted on the control unit 1, the ignition signal control unit 101 outputs four systems of ignition control signals 101a to 101d for four cylinders, The overlap request signal control unit 110 outputs one system of overlap request control signals.

  The discharge unit 2 is provided in the internal combustion engine separately from the ignition coils 3a to 3d and the ignition plugs 4a to 4d and the control unit 1, and includes a booster circuit 203 and four ignition coils 3a to 3d for four cylinders. Is connected by a high voltage line of about 500V. Discharge is started at a normal ignition timing for the target cylinder based on the primary current generated based on the ignition control signals 101a to 101d by switching of the igniters 301a to 301d incorporated in the ignition coils 3a to 3d. Then, the boosted voltages 203a to 203d necessary for maintaining the discharge state are applied to the secondary side of the ignition coils 3a to 3d via the high voltage line. In the engine cylinder (cylinder), the spark plugs 4a to 4d are discharged to the air-fuel mixture and ignited, and so-called overlap discharge is induced following normal discharge. Each part is connected by a wire harness.

  In the internal combustion engine ignition device according to the first embodiment, the discharge unit 2 is installed in the internal combustion engine as a separate body from the control unit 1 on which the ignition control device 100 is mounted. Since the four systems of ignition control signals 101a to 101d and high voltage lines necessary for overlap discharge are required for several cylinders, the number of signal lines for requesting overlap discharge to the discharge unit 2 is also equal. Whereas the overlap request signal control unit 110 of the ignition control device 100 requests the discharge unit 2 for the overlap discharge by the overlap request control signal, the signal of the discharge unit 2 is connected with one signal line. It is characterized in that it is connected to the overlap time control circuit 202. In this way, if the overlap request signal control unit 110 is connected to the discharge unit 2 in a single signal system to control the signal, the wiring harness connection can be minimized, and further, depending on the layout. Even when the installation interval of each part becomes long, the cost increase of the wire harness connection can be suppressed.

  Further, the overlap time determination unit 113 in the ignition control device 100 determines the overlap time, which is control information necessary for executing overlap discharge, and the overlap operation region determination unit 112 determines an operation region due to overlap discharge, The overlap switching determination unit 111 performs determination between overlap discharge and normal discharge, and determines whether the overlap discharge is successful. Each of these units calculates control information necessary for executing overlap discharge, but finally the overlap request signal control unit 110 calculates the form and timing of the output signal.

  Further, the cylinder switching circuit 201 in the discharge unit 2 determines the ignition timing of each cylinder according to the ignition control signals 101a to 101d, and the overlap time control circuit 202 according to the information (request contents) of the overlap request control signal. The superposition time is controlled, and the booster circuit 203 supplies the boost voltages 203a to 203d necessary for the superposition discharge to the cylinders via the high voltage line in accordance with the timing of inputting the ignition control signals 101a to 101d and the superposition request control signal for each cylinder. Applied to the secondary side of the corresponding ignition coils 3a to 3d every time. As a result, an overlap discharge output (secondary voltage, secondary current) is induced with the corresponding one of the spark plugs 4a to 4d in each cylinder, and spark discharge due to the occurrence of the overlap discharge is generated in the target cylinder. Since the ion current generated by the occurrence of overlap discharge can be detected by the ion detectors 320a to 320d of the ignition coils 3a to 3d and sent to the overlap discharge failure determination device 500 of the control unit 1, Determine failure of discharge unit 2 or ignition control device 100 (overlap request control signal from overlap request signal control unit 110) associated with overdischarge based on the result of measuring the rise timing of the ionic current detected by discharge failure determination device 500 can do.

  FIG. 2 is a block diagram showing a detailed configuration of the over-discharge failure determination apparatus 500 mounted on the control unit 1. The overlapped discharge failure determination apparatus 500 includes an input processing unit 501 that takes in ion currents detected by the ion detection devices 320a to 320d of the ignition coils 3a to 3d, and timings of ignition control signals 101a to 101d from the ignition signal control unit 101. The rise time measurement unit 502 that measures the rise time of the ionic current based on the rise time, the rise time by the rise time measurement unit 502 and the request contents of the overlap request control signal from the overlap request signal control unit 110 of the ignition control device 100 Based on the result of comparing the overlap request time with a predetermined period set in advance, the overlap discharge abnormality determination unit 503 that determines abnormality of the discharge unit 2 or the overlap request control signal and the overlap by the overlap discharge abnormality determination unit 503 In response to an abnormal determination of the request control signal, during the predetermined period during the execution of overlap discharge Overlap request control signal failure determination unit 504 for determining failure of the overlap request control signal when the number of short rise times exceeds the second predetermined ratio or continues for a predetermined time, and overlap discharge abnormality determination When the abnormality determination of the discharge unit 2 is received by the unit 503 and the number of short rise times during the predetermined period exceeds the first predetermined ratio and is less than the second predetermined ratio during the execution of the overlap discharge And a discharge unit failure determination unit 505 for determining a failure of the discharge unit 2. Again, each part is connected by a wire harness.

  In this overlapped discharge failure determination apparatus 500, when signals indicating ion currents from the ion detection apparatuses 320a to 320d built in the ignition coils 3a to 3d of the respective cylinders are input to the input processing section 501, the input processing section 501. Then, a digital signal converted into a voltage value corresponding to the ionic current is sent to the rise time measuring unit 502, and the rise time measuring unit 502 is additionally provided with an ignition timing indicated by the ignition control signals 101a to 101d from the ignition signal control unit 101. Ignition timing information corresponding to is input. Therefore, the rise time measurement unit 502 measures the time from the ignition timing to the rise of the ion current (rise time of the ion current) and sends the measurement result to the overlapped discharge abnormality determination unit 503.

  The overlap discharge abnormality determination unit 503 sets in advance the rise time measured by the rise time measurement unit 502 and the overlap request time included in the request content of the overlap request control signal from the overlap request signal control unit 110 of the ignition control device 100. The abnormality of the discharge unit 2 or the overlap request control signal is determined based on the result of comparison in the predetermined period. Further, based on the abnormality determination result, the overlap request signal failure determination unit 504 determines the failure of the overlap request control signal according to the abnormality detection rate in a predetermined ignition timing or a predetermined period, and the discharge unit failure determination unit 505 Confirms the failure of the discharge unit 2.

  FIG. 3 is a view showing the basic configuration of the ignition coil 3 a provided in the internal combustion engine ignition device according to the first embodiment, including the correspondence with the discharge unit 2. Here, the configuration of an ignition coil 3a that performs spark discharge when inducing a superimposed discharge output with superimposed discharge applied in the present invention is shown for one cylinder. In the ignition coil 3a, the primary current generated based on the ignition control signal 101a and the predetermined constant voltage (+ 12V) are input via the igniter 301a on the primary side, and according to the content of the overlap request of the overlap request control signal. Overlap discharge output 401a between spark plug 4a and the secondary side to which the boosted voltage generated by booster circuit 203 in which the overlap time is instructed by overlap time control circuit 202 and controlled by control circuit 302 is applied is applied. Induces. As a result, spark discharge with overlap discharge is performed in one cylinder. At this time, the ion current detection device 320a detects the ion current generated in accordance with the combustion in the cylinder. The ion current detection device 320a has a circuit configuration connected to an amplifier using a diode, a resistor, and a capacitor. For example, a well-known technique as disclosed in Patent Document 2 can be applied.

  FIG. 4 is a timing chart showing waveforms relating to input / output of the ignition coil 3a. Here, the primary current and discharge output (secondary voltage, secondary current) for the ignition control signal 101a and the overlap request control signal in the ignition coil 3a when the air-fuel mixture compressed in one cylinder (cylinder) of the internal combustion engine is ignited. ) 401a and the relationship between ion currents.

  More specifically, since the booster circuit 203 is controlled not to operate when there is no overlap discharge, the transistor switching operation in the igniter 301a is performed at the timing when the rising of the rectangular wave of the ignition control signal 101a is turned ON. The magnetic energy is stored in the ignition coil 3a by flowing a primary current in the range of 5 to 10A to the primary side of the ignition coil 3a, and the falling edge of the rectangular wave of the ignition control signal 101a is turned off (so-called ignition timing). Thus, when the switching operation of the transistor in the igniter 301a is performed and the primary current is cut off, a high secondary voltage is generated on the secondary side of the ignition coil 3a, whereby the spark plug 3a is discharged. The flow of the discharge current (secondary current) at this time is in the direction indicated by the dotted arrow shown in FIG.

  Next, when superposed discharge is performed, the switching operation of the transistor of the igniter 301a is performed at a timing when the rectangular wave of the ignition control signal control 101a is turned ON, and when the primary current is cut off, the secondary side of the ignition coil 3a is increased. When the secondary voltage is generated, the spark plug 3a starts discharging. Here, the discharge unit 2 receives information on the overlap request control signal (contents of the overlap request), determines the time for the overlap time control circuit 202 to execute overlap discharge, and determines the ignition timing of the target cylinder. The switching circuit 201 determines the cylinder to be subjected to the overlap discharge in the boost circuit 203 based on the ignition control signal 101a, and supplies the boost voltage 203a necessary for the overlap discharge via the high voltage line in accordance with the timing when the primary current is cut off. Thus, the booster circuit 203 is applied by communicating with the secondary side of the ignition coil 3a corresponding to the target cylinder. At this time, in the ignition coil 3a, a secondary discharge output 401a is induced between the ignition plug 4a and the secondary side to which the boosted voltage 203a from the booster circuit 203 whose duration is controlled in conjunction with the control circuit 302 is applied. As a result, spark discharge with overlapping discharge is performed in one cylinder. The flow of the discharge current (secondary current) at this time is in the direction indicated by the solid arrow in FIG. If the boost voltage from the booster circuit 203 is cut off at the timing when the overlap time control circuit 202 ends the overlap discharge, the overlap discharge ends.

  During the discharge described above, no current can flow through the ion detector 320a, and no ion current can be detected during the discharge. During the discharge, the ion current during combustion is detected. The electromotive force for detecting is charged. When the discharge ends, the ion current flows in the direction indicated by the solid line arrow in FIG. 3 due to the ion state generated by the combustion state, so that the ion current is detected and the value of the ion current is the failure of the overdischarge of the control unit 1 It is sent to the determination device 500.

  In FIG. 4, when there is an overlap request by the overlap request control signal, the discharge is extended during the overlap time (tw) from the point A of the ignition timing in the ignition control signal 101a, so that the discharge voltage is applied during this time. The ignition performance of the air-fuel mixture in the cylinder (cylinder) can be improved. Even if the combustion is started during the discharge, the ion current cannot be detected. Therefore, the ion current rises after the period dt1 from the ignition timing after the discharge ends, and is detected according to the combustion state. Become. The overlap request control signal is controlled to output an ON signal at an earlier timing (td) time than the ignition control signal 101a. In this control, the calculation timing of the overlap request control signal is not necessarily calculated at the ignition timing, but in order to take measures against the case where it is calculated at a predetermined microcomputer calculation timing such as every 10 ms, Although it depends on the determination timing 202, in order to ensure that the overlap time control circuit 202 can determine the overlap request information and the overlap time information at the earliest timing when the overlap request information is determined. It is. It is desirable that at least the (td) time is the same timing (td = 0) as the timing when the ignition control signal 101a is turned on or earlier.

  In addition, after point B in FIG. 4, there is a state in which overlap discharge is not executed due to an abnormality of the overlap request control signal or an abnormal state of the discharge unit 2 even though there is an overlap request. ing.

When the overlap discharge is not executed, the discharge is completed only in the discharge time (th), so that the combustion is shortened, and the rise of the ion current rises in the period (dt0) and can be detected. This state is equivalent to the case where overlap discharge is not performed. Although the overlap request signal control unit 110 originally calculates the overlap time (tw), the time from the ignition timing to the rise of the detected ion current value is detected as a shorter period (dt0). The Therefore, the overlapped discharge failure determination apparatus 500 can determine that the overlapped discharge is not performed when the period (dt0) is short by comparing the overlap time (tw) and the period (dt0). it can.

Here, as a premise for determining the state of the overlap discharge from the detection information of the ion current value, when the ion current can be observed first without the overlap discharge, the ignition plug 4a and the ignition coil 3a themselves are out of order. Therefore, if the rise time of the ion current is short during the execution of the overlap discharge, it is determined that the discharge unit 2 or the signal line of the overlap request control signal is broken. can do.

  For example, if the signal line of the overlap request control signal is disconnected, the information from the signal line of the overlap request control signal cannot be determined by the discharge unit 2 and can be processed only with no overlap discharge. The rise time of the current is shortened. On the other hand, for example, even when the booster circuit 203 of the discharge unit 2 is out of order, the rise time of the ion current is shortened at a rate of almost 100%. Here, since it is difficult to specify whether the failure of the overlap request control signal or the discharge unit 2 is actually a failure, if it is determined that the overlap request control signal or the discharge unit 2 has failed, the spark plug 4a or the ignition coil The failure part can be specified separately from the failure 3a.

  In addition, if it is necessary to determine whether the overlap request control signal is faulty or the discharge unit 2 is faulty from a service viewpoint, if an abnormality close to 100% is detected, the overlap request control signal side First, it is sufficient to instruct confirmation of disconnection or connection failure on the overlap request control signal side in the check flow on the service. As a result, if the abnormality is determined again in spite of the absence of an abnormality, a check on the discharge unit 2 side is instructed by setting a failure on the discharge unit 2 side for the next service check. Just do it. As a result, it is possible to specify a failure site for an abnormality close to 100%, and it is possible to save the trouble of replacing the entire ignition device.

  Further, when the abnormality rate is lower than 100% described above, for example, about 50%, similarly, it is difficult to specify whether the overlap request control signal is faulty or the discharge unit 2 is faulty. However, since it is a rare frequency abnormality, the failure mode may be a contact failure of the connection on the overlap request control signal side or a functional failure of the discharge unit 2 itself. As a failure occurrence pattern, a contact failure of the overlap request control signal can be confirmed relatively easily. Therefore, it is preferable to determine such a rare frequency abnormality as an abnormality on the discharge unit 2 side. Therefore, as a service check flow, if the focus is on the replacement on the discharge unit 2 side and an abnormality is detected even after the replacement, the contact failure of the connection with the discharge unit 2 side is also improved at the time of replacement. In particular, it is sufficient to instruct confirmation of poor contact of the signal connection with the control unit 1 side. Incidentally, if not only the ratio for all cylinders but also the ratio of abnormality for each cylinder is determined and an abnormality occurs biased to a specific cylinder, there is a high possibility of an abnormality on the discharge unit 2 side. Therefore, it can also be determined that there is an abnormality on the discharge unit 2 side.

  In addition, although not shown in the drawings, as another method for determining the failure part, a circuit configuration is adopted in which the output line of the overlap request control signal output from the ignition control device 100 of the control unit 1 is output at 5 V when disconnected, and the discharge is performed. The input processing on the unit 2 side may also be configured as a circuit configuration that recognizes that no overlap request is made at 0V. According to such a configuration, when there is no overlap request, 0V is output, and if this is input as a monitor circuit to the AD converter of the microcomputer in the control unit 1 or the input port that can recognize the High / Low port, the calculation is performed. By comparing the state of the overlap request control signal with the input state of the monitor circuit, it is possible to specify that the overlap request control signal is faulty when the rise time of the ion current is shortened.

  FIG. 5 is a flowchart showing an operation process for measuring the rise timing of the ion current by the rise time measuring unit 502 in the overdischarge failure determination apparatus 500. This operation process is executed at each ignition timing, for example, by an interrupt process of a microcomputer control program. As a timer for measuring time, a necessary resolution (minimum time unit) is selected from a microcomputer oscillation clock divider. Use a function that can be automatically measured during interrupt processing.

  Referring to FIG. 5, first, in the rise time measurement unit 502, the detected ion current input to the input processing unit 501 based on the ignition control signal 101 a from the ignition signal control unit 101 is the ignition timing (ignition timing). It is determined whether or not (step S501). As a result of this determination, if the ignition timing is reached, the operation processing is terminated after the rise time measurement timer clear (step S502) processing for clearing the timer and stopping the timer measurement is performed. It is determined whether or not the ion has risen by determining whether or not the ion current value Vion has exceeded a predetermined current value Vsl (step S503). If the result of this determination is that the ion rises (if Vion> Vsl), the timer value at that time is set and stored as the ion rise time (dt) (step S504), and then the timer is counted up to The process of the rise time measurement timer count-up (step S505) for continuing the measurement is performed and then the operation process is terminated. If the ion rise is not performed (Vion ≦ Vsl), the ion rise time (dt) is set (step After jumping to S504) and performing the rise time measurement timer count-up process (step S505) for continuing the timer measurement, the operation process is terminated.

  FIG. 6 shows an operation process from abnormality determination of overlap discharge to failure determination according to the overlap discharge abnormality determination unit 503, the overlap request control signal failure determination unit 504, and the discharge unit failure determination unit 505 in the overlap discharge failure determination apparatus 500. It is a flowchart. However, here, the case where the operation process leading to the failure determination is performed for one cylinder (cylinder) is illustrated, and for example, it is executed as an interrupt process based on the ignition timing. The operation processing is performed in the form of the output signal timing as shown in FIG.

  Referring to FIG. 6, the overlap discharge abnormality determination unit 503 first determines whether or not the overlap discharge request is being executed based on the request content of the overlap request control signal from the overlap request signal control unit 110. It is determined by determining whether or not (step S601). As a result of this determination, if the overlap discharge is not being executed (if the overlap discharge request is not executed), the operation process is terminated, but if the overlap discharge is being executed (if the overlap discharge request is being executed), After performing the process of counting the number of ignitions for the same cylinder (step S602), it is determined whether or not 100 ignitions have elapsed, whether or not a predetermined number of ignitions (for example, 100 ignitions) at which overlap discharge should be performed has been reached ( This is performed according to step S603). As a result of the determination, if 100 ignitions have elapsed, the process of resetting the number of times of ignition is reset (step S604), then the process of overlapping discharge abnormality determination is cleared (step S605), and the number of times of accumulation (ΣCnt) is cleared (step S606). ), The operation process is terminated. If 100 ignitions have not elapsed, the latest detected ion current rise time (dt) explained in FIG. 5 is checked until the number of ignitions reaches 100. Whether or not the rising time (dt) is normal is determined by determining whether the rising time (dt) is less than the predetermined time dtx (that is, whether dt <dtx) (step S607). .

The result of this determination, (if dt ≧ dtx) lever rise time (dt) is cry less than the predetermined time dtx, but ends the operation process after performing the process of overlapping the discharge abnormality determination cleared (step S608), (if dt <dtx) Oh lever rise time (dt) is less than a predetermined time dtx, after the process of overlapping is determined that overlapping discharge abnormal discharge abnormality determination set (step S609), abnormality determination count Is accumulated (ΣCnt) count-up (step S610).

  Next, it is determined whether (ΣCnt)> ScntH (90) or not (step S611) as to whether or not the number of integrations (ΣCnt) exceeds a second predetermined ratio ScntH (for example, 90 times). Do. If (ΣCnt)> ScntH (90) as a result of this determination (if the ratio exceeds 90/100), it is determined that the overlap request control signal is abnormal and the overlap request control signal failure determination unit 504 is overlapped. After performing the processing of the request control signal abnormality confirmation set (step S617), the processing of the overlap request control signal stop processing set (step S616) for stopping and setting the overlap request control signal as fail safe is performed, and then the operation processing is ended. . As a result, the overlap request control signal failure determination unit 504 receives the overlap determination control signal abnormality determination by the overlap discharge abnormality determination unit 503, and the number of short rise times during the predetermined period during the execution of the overlap discharge is the second. When the predetermined ratio is exceeded, the failure of the overlap request control signal is determined.

  As a result of this determination, if (ΣCnt)> ScntH (90) is not satisfied {if (ΣCnt) ≦ ScntH (90) with a ratio of 90/100 or less}, then the first predetermined ratio ScntL (for example, It is determined by determining whether (ΣCnt)> ScntL (20-30) or not (step S612). As a result of this determination, if (ΣCnt)> ScntL (20-30) (if the ratio exceeds 20-30 / 100), it is determined that the discharge unit 2 is abnormal and the discharge unit failure determination unit 505 is determined. After performing the process of the discharge unit abnormality confirmation set (step S615), the process of the overlap request control signal stop process set (step S616) for stopping and setting the overlap request control signal is performed, and then the operation process is ended. As a result, the discharge unit failure determination unit 505 receives the abnormality determination of the discharge unit 2 by the overlap discharge abnormality determination unit 503, and the number of short rise times in the predetermined period during the execution of the overlap discharge is the first predetermined ratio. Is exceeded and less than the second predetermined ratio, the failure of the discharge unit 2 is determined.

  Further, if (ΣCnt)> ScntL (20-30) (if the ratio is 20-30 / 100 or less), it is determined that there is no abnormality and the discharge unit abnormality confirmation reset for the discharge unit failure determination unit 505 is performed. After performing the process of (Step S613) and the overlap request control signal abnormality confirmation reset (Step S614), the operation process is terminated.

  Incidentally, in the case where continuous operation processing is performed not only on one cylinder but also on other cylinders, the result of the determination whether or not (ΣCnt)> ScntH (90) is satisfied (step S611). , (ΣCnt)> ScntH (90), the number of cylinders n = 1 to 4 is subsequently determined whether (ΣCnt)> ScntH (90) or not. If (ΣCnt)> ScntH (90), it is determined that the overlap request control signal is abnormal, and the overlap request control signal failure determination unit 504 is shifted to the processing of the overlap request control signal error determination set (step S617). Otherwise, it may be shifted to the determination (step S612) whether (ΣCnt)> ScntL (20-30).

  Note that FIG. 6 illustrates the case where the abnormality is determined based on the result of counting the number of ignitions, but instead of this, the rise time (dt) for determining whether or not the above-described rise time (dt) is in a normal state. Is determined to be shorter than the predetermined time dtx (step S607). Based on the result of the determination that the rise time (dt) is shortened, the duration is determined and the failure is confirmed when the predetermined time continues. Even if it does, the same function is obtained.

  In any case, according to the ignition device for an internal combustion engine according to the first embodiment, the ignition control device 100 includes the overlap request signal control unit 110 that outputs the overlap request control signal related to the request for overlap discharge with one signal line. The overdischarge type discharge unit 2 is provided in the internal combustion engine separately from the ignition coils 3a to 3d and the ignition control device 100, and the ignition control signals 101a to 101d from the ignition signal control unit 101 in the ignition control device 100 are provided. Accordingly, the discharge unit 2 switches the cylinder corresponding to the ignition coils 3a to 3d, and corresponds to the switched cylinder after controlling the overlap discharge time according to the overlap request control signal from the overlap request signal control unit 110. A boost voltage for overlap discharge is applied to the ignition coils 3a to 3d, and the ignition coils 3a to 3d are generated based on the ignition control signals 101a to 101d. A primary current and a predetermined constant voltage (+ 12V) are input on the primary side, and the overlapped discharge outputs 401a to 401d are connected to the corresponding ones of the spark plugs 4a to 4d from the secondary side to which the boosted voltages 203a to 203d are applied. When the induced ion current is detected by the ion detectors 320a to 320d of the ignition coils 3a to 3d, and the multiple discharge failure determination device 500 measures the rise timing of the detected ion current, the discharge associated with the multiple discharge In order to determine the failure of the unit 2 or the ignition control device 100 (the overlap request control signal of the overlap request control unit 110), it can be applied to a multi-cylinder internal combustion engine without any problem in mounting, and the ignition control is performed by effectively executing the overlap discharge. This increases the degree of freedom in layout, eliminates problems such as battery deterioration and rise, and Sometimes so that the failure site can be judged to accurately.

  In particular, the abnormality of the discharge unit 2 is that the number of short rise times of the detected value of the ion current during a predetermined period during the execution of the overlap discharge exceeds the first predetermined ratio and is less than the second predetermined ratio. In this case, since the discharge unit failure determination unit 505 determines the discharge unit failure as a failure of the discharge unit by the overlapped discharge abnormality determination unit 503 that has determined the discharge unit abnormality, the failure part is preferentially combined with a service check instruction in the market. Can be specified.

  In addition, the abnormality of the overlap request control signal from the overlap request signal control unit 110 in the ignition control device 100 is caused by the fact that the number of short rise times of the detected value of the ion current during the predetermined period during execution of the overlap discharge is the second predetermined value. If the ratio exceeds or the abnormality of the overlap request control signal is determined for a predetermined time, the overlap discharge abnormality determination unit 503 determines the failure of the overlap request control signal for the overlap request control signal failure determination unit 504. Therefore, similarly, it is possible to preferentially identify the location of the failure together with the service check instruction in the market.

  Although the internal combustion engine ignition device according to the first embodiment has been described as being applied to a four-cylinder internal combustion engine, it can be similarly applied to a multi-cylinder internal combustion engine other than the four-cylinder engine. The ignition device for use is not limited to the one disclosed in the first embodiment.

DESCRIPTION OF SYMBOLS 1 Control unit 2 Discharge unit 3, 3a-3d Ignition coil 4, 4a-4d Spark plug 100 Ignition control device 101, 101a-101d Ignition control signal 201 Cylinder switching circuit 202 Overlap time control circuit 203 Booster circuit 203a-203d Booster voltage 301 , 301a to 301d igniter 302 control circuit 320a to 320d ion detector 401 discharge output 401a to 401d overlap discharge output 500 overlap discharge failure determination device 501 input processing section 502 rise time measurement section 503 overlap discharge abnormality determination section 504 overlap request control signal failure Determination unit 505 Discharge unit failure determination unit

Claims (5)

A plurality of spark plugs respectively disposed in the plurality of cylinders of the multi-cylinder internal combustion engine, and a plurality of ignition coils for inducing overlapping discharge outputs for generating spark discharges between the plurality of spark plugs, respectively , An overlap discharge type discharge unit for performing overlap discharge for extending the spark discharge time, and an ignition control signal for controlling an ignition state in each of the plurality of cylinders to each of the plurality of ignition coils An ignition control device for an internal combustion engine comprising:
The ignition control device generates a plurality of ignition control signals for each of the plurality of ignition coils to control the ignition timing of the spark discharge; An overlap request signal control unit that outputs an overlap request control signal for controlling the state with a single signal line;
The discharge unit switches cylinders corresponding to the plurality of ignition coils in accordance with the ignition control signal, and controls the time of the overlap discharge in accordance with the overlap request control signal, and corresponds to the switched cylinder. Applying a boosted voltage for multiple discharge to each of the plurality of ignition coils,
The plurality of ignition coils respectively input a primary current and a predetermined constant voltage generated based on the ignition control signal to the primary side, and correspond to the plurality of ignition plugs from the secondary side to which the boosted voltage is applied. Each of which includes an ion detector that induces the overlapped discharge output with an object and detects an ionic current generated according to combustion in the corresponding cylinder at the time of the overlapped discharge,
A multiple discharge failure determination device for determining a failure of the discharge unit or the ignition control device associated with the multiple discharge based on a result of measuring a rising timing of the ion current detected by the ion detection device; An ignition device for an internal combustion engine characterized by the above.   2. The internal combustion engine ignition device according to claim 1, wherein the overlapped discharge failure determination device is mounted in a control unit that controls the internal combustion engine together with the ignition control device.   3. The ignition device for an internal combustion engine according to claim 1, wherein the overlapped discharge failure determination device measures a rise time of the ion current based on a timing of the ignition control signal from the ignition signal control unit. And the overlap request time included in the request content of the overlap request control signal from the overlap request signal control unit of the ignition control device during a predetermined period of time An ignition apparatus for an internal combustion engine, comprising: an overdischarge abnormality determination unit that determines abnormality of the discharge unit or the overlap request control signal based on the result of comparison in (1). 4. The ignition device for an internal combustion engine according to claim 3, wherein the overlap discharge failure determination device receives an abnormality determination of the overlap request control signal by the overlap discharge abnormality determination unit , and the rise time is short during execution of the overlap discharge. An ignition device for an internal combustion engine, comprising: an overlap request control signal failure determination unit that determines a failure of the overlap request control signal when the duration determined as follows continues for a predetermined time . Between a plurality of spark plugs respectively disposed in a plurality of cylinders of a multi-cylinder internal combustion engine
Each of them induces a superimposed discharge output for generating a spark discharge, and the superimposed discharge output
Multiple ignition coils that can detect the ionic current generated according to the combustion in the cylinder
Overdischarge type discharge unit that performs overlap discharge to extend the spark discharge time
In addition, the ignition state in each of the plurality of cylinders is controlled for each of the plurality of ignition coils.
An ignition control device that outputs an ignition control signal for
The ignition control signal is generated for each of the plurality of ignition coils to generate a spark discharge point.
A plurality of ignition signal control units for controlling the fire timing, and the state of the overlap discharge with respect to the discharge unit;
An overlap request signal control unit that outputs a overlap request control signal for controlling the state with a single signal line.
An ignition control device characterized by that.

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