JP2009243467A - Glow plug control device and glow plug control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glow plug control device and a glow plug control system reducing heat resistance performance or heat radiation capacity required for a switching element turning on and off electricity supply to a glow plug. <P>SOLUTION: This system is provided with a power element TR (switching element) turning on and off electricity supply to the glow plug provided in a combustion chamber of a diesel engine, a control IC 31 (electricity supply control device) controlling operation of the power element TR, and a temperature transducer 32 (temperature detection means) detecting temperature of the power element TR. The control IC 31 includes an electricity supply limit means limiting electricity supply quantity to the glow plug in high temperature abnormality time when temperature detected by the temperature transducer 32 gets not less than predetermined temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a glow plug control device that controls energization to a glow plug provided in a combustion chamber of an internal combustion engine.

  2. Description of the Related Art Conventionally, DPF devices that collect particulate matter (PM) discharged from a diesel engine (internal combustion engine) have been known. In this DPF device, a regeneration process is required for burning the PM when the collected PM exceeds a predetermined amount. Therefore, in Patent Document 1 and the like, fuel injection control is proposed in which the post-injection is performed after the main injection to inject fuel, thereby forcibly raising the temperature of the exhaust gas and forcibly removing the collected PM. Yes.

JP 2006-152891 A

  Then, the present inventor examined raising the temperature of the exhaust gas by increasing the main injection amount separately from the execution of the post injection. According to this study, it was found that simply increasing the main injection amount increases the engine speed (hereinafter referred to as “NE”), which gives the driver an uncomfortable feeling. In particular, at the time of NE low speed such as during idling, there is a great sense of incongruity due to NE increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a glow plug control device and a glow plug control system that suppress an increase in engine rotation speed when the regeneration process of the DPF device is executed. is there.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention according to claim 1 is applied to an internal combustion engine provided with a glow plug provided in a combustion chamber of the internal combustion engine and a filter device (DPF: Diesel Particulate Filter) for collecting particulate matter in exhaust gas. Assumption. The load device is energized so as to increase the electrical load on the battery charged with the internal combustion engine as a drive source when the regeneration process is performed to increase the exhaust temperature so as to remove the collected particulate matter from the filter device. A regeneration energization means for controlling is provided, wherein the glow plug is energized when the internal combustion engine is started, and is also energized when the regeneration process is performed as the load device.

  According to this, when the regeneration process is executed, the load device is energized and controlled so as to increase the electrical load to the battery charged with the internal combustion engine as a drive source. Therefore, when the regeneration process such as increasing the main injection amount is performed Even so, the increase in NE can be suppressed.

  Further, in the present invention, the glow plug is energized when the internal combustion engine is started and energized when the regeneration process is executed. In other words, the original use of the glow plug is to assist the initial ignitability at the start of the internal combustion engine by preheating the combustion chamber. Separately from this application, the load during the regeneration processing of the filter device is executed. Use glow plugs as equipment. For example, contrary to the present invention, when a vehicle headlamp is used as a load device, the headlamp is turned on when the regeneration process is executed against the driver's intention while driving the vehicle, giving the driver a sense of incongruity. Problems occur. In contrast, in the present invention, since the glow plug is used as a load device as described above, the driver does not feel uncomfortable even when the glow plug is activated during the regeneration process while driving the vehicle. While avoiding, an increase in NE at the time of executing the reproduction process can be suppressed.

  By the way, since the energization to the glow plug is a large current, the switching element for turning on / off the energization generates heat (see JP-A-2006-153293, etc.). For this reason, there is a concern that the switching element may generate heat excessively and be damaged. Moreover, when the glow plug is energized as a load device during the DPF regeneration process as described above, the ambient temperature of the switching element becomes extremely high in such a DPF regeneration process. Therefore, the present inventor has obtained the knowledge that, when trying to implement the invention according to claim 1, the concern about thermal damage of the switching element becomes remarkable.

  Based on this knowledge, in the invention according to claim 2, the switching element for turning on / off the energization to the glow plug, the energization control device for controlling the operation of the switching element, and the temperature of the switching element are preset. Determining means for determining whether or not the high temperature abnormality is equal to or higher than a predetermined temperature, and when the determination means determines that the high temperature abnormality is present, the energization control device applies power to the glow plug. It has the electricity supply restriction | limiting means which restrict | limits the electricity supply amount, It is characterized by the above-mentioned. According to this, the thermal damage of the switching element by energizing the glow plug in a high temperature environment can be avoided, which is preferable.

  Here, when determining whether or not it is in a high temperature abnormality state, if the current flowing through the switching element is measured and an attempt is made to determine that there is a high temperature abnormality when the measured current value exceeds a threshold value, the following problem occurs: Occurs. That is, if the switching element has a high ambient temperature, the switching element temperature (hereinafter referred to as “element temperature”) increases even if the measured current value is the same. That is, an accurate element temperature cannot be assumed from the current value flowing through the switching element. Therefore, in the determination based on the above-described current value, it is necessary to select a switching element with a sufficient heat resistance so that a heat generation failure does not occur even at the assumed maximum ambient temperature. Therefore, an inexpensive switching element with low heat resistance cannot be selected. Alternatively, a heat dissipation means such as a heat sink having a high heat dissipation capability is required. In particular, when a glow plug is energized as a load device during DPF regeneration processing, a current flows through the switching element in a state where the ambient temperature is extremely high. A switching element must be selected with a very large margin in performance.

  In order to solve this problem, the invention according to claim 3 further comprises temperature detection means for detecting the temperature of the switching element, and the determination means is in the abnormal state of the high temperature based on the temperature detected by the temperature detection means. It is characterized by determining whether or not.

  According to this, since the temperature (element temperature) of the switching element is directly detected by the temperature detection means, it is possible to acquire an accurate element temperature as compared with the case where a high temperature abnormality is determined from the current value flowing through the switching element. Accordingly, it is possible to eliminate the need for a margin in the heat resistance performance required for the switching element, so that it is possible to reduce the heat resistance performance or the heat radiation capability required for the heat radiation means such as a heat sink.

  According to a fourth aspect of the present invention, the regeneration energization means performs energization control during the regeneration process on a plurality of load devices including the glow plug, and other load devices excluding the glow plug. The amount of current applied to the is increased when compared with the normal time when the high temperature is abnormal. According to this, since the electrical load is increased by a plurality of load devices, NE increase can be sufficiently suppressed as compared with the case where the electrical load is increased by one load device.

  Further, as a specific example of energization control when there are a plurality of other load devices, the energization amount to the plurality of other load devices is increased simultaneously when the high temperature is abnormal (Claim 5), or the high temperature In the event of an abnormality, the amount of energization to the plurality of other load devices may be alternately increased so as to increase the amount of energization to any one of the plurality of other load devices (Claim 6). According to these, even when the energization to the glow plug is restricted due to a high temperature abnormality, the increase in the electric load during the regeneration process can be suitably compensated for by energizing the other load devices.

  Here, specific examples of other load devices are attached to an electric heater (intake heater) for heating the intake air sucked into the combustion chamber, an electric heater (seat heater) for heating the passenger seat of the vehicle, and a rear windshield. And electric heaters (wind shield heaters), radiator electric fans, and the like. If these load devices are activated during the regeneration process, for example, the headlamp is turned on against the driver's will, which gives the driver a sense of discomfort. Therefore, the invention according to claim 7 is characterized in that the regeneration energization means prohibits the energization of the other load device at the normal time even when the regeneration process is executed. According to this, since the opportunity for other load devices to operate during the regeneration process can be reduced, the chance of giving a sense of incongruity as described above can be reduced. Even if the glow plug is operated as a load device, the driver does not feel uncomfortable.

  The invention according to claim 8 is characterized in that the regeneration energization means lengthens the energization time of the load device when the high temperature is abnormal as compared with the normal time. According to this, even when energization to the glow plug is restricted due to a high temperature abnormality, the energization time to the load device is lengthened, so that an increase in the electric load during the regeneration process can be suitably compensated.

  The invention according to claim 9 is characterized in that execution of the regeneration process is postponed when the high temperature is abnormal. According to this, it is possible to avoid increasing the electric load during the regeneration process in a state where the energization to the glow plug is controlled.

  As a specific example of limiting the energization amount to the glow plug, as described in claim 10, the energization to the switching element is cut off or the energization duty ratio is reduced. According to this, it is possible to easily realize zeroing or reducing the energization amount.

  According to an eleventh aspect of the present invention, the energization control device controls the operation of the switching element based on a command signal output from the command control device, and the energization by the energization limiting unit against the command content of the command signal. When the restriction is executed, a diagnosis signal for notifying the execution is output to the command control device. According to this, in energizing the load device during the regeneration process, it is possible to execute energization control to the load device suitable for the diagnosis signal.

  The invention according to claim 12 is characterized in that the glow plug is provided in each of the plurality of cylinders of the internal combustion engine, and the energization control device outputs the diagnosis signal for each of the glow plugs. Therefore, it is possible to finely control energization to the load device suitable for the diagnosis signal. That is, the power consumed by other load devices can be adjusted according to the number of glow plugs that are stopped due to a high temperature abnormality. Alternatively, it is possible to adjust the power consumed by the glow plug by increasing the energization amount to the glow plug that has not stopped abnormally at high temperatures within a range where the glow plug does not fail.

  Generally, when the glow plug is energized for the purpose of initial ignitability assist, the duty ratio is increased stepwise (see FIG. 19B). At this time, the power consumption at the glow plug increases for several seconds due to the inrush current to the glow plug (see FIG. 19A). However, when the glow plug is energized at the time of the regeneration process as described above, if the power consumption increases due to the inrush current, the magnitude of the electric load will fluctuate. In order to suppress this, NE will be fluctuated.

  In view of this point, in the invention described in claim 13, when energization of the glow plug is started as the regeneration process is executed, the duty ratio of energization to the switching element is gradually increased (see FIG. 19D). ). Therefore, it is possible to avoid an increase in power consumption at the glow plug due to the inrush current for several seconds (see FIG. 19C). Therefore, it is possible to avoid fluctuations in the magnitude of the electric load when the glow plug is energized during the regeneration process, and to solve the above-described NE fluctuation problem.

  In the invention described in claim 14, the glow plug is energized (glow at start-up) so as to assist the initial ignitability at the start of the internal combustion engine, and also stabilizes combustion during the period after the start of the internal combustion engine. It is characterized by being energized (after-glow).

  Here, as described above, when performing conventional control that assumes the element temperature from the current value flowing through the switching element, it is necessary to increase the current threshold value for determining the high temperature abnormality. When glowing is performed, there is a concern that a current slightly lower than the current threshold flows continuously over a long period of time (period after start-up). In this case, although it is not determined that the temperature is abnormal, there is a risk of causing deterioration of the switching element or the like. There is. In response to such a concern, according to the invention described in claim 14, since the element temperature is directly detected, a high temperature abnormality can be accurately determined even in such afterglow, and the amount of current supplied to the glow plug is suitable. Can be limited.

  Incidentally, examples of the case where the afterglow is performed include a case where the afterglow is applied to an internal combustion engine having a low compression ratio and a case where the internal combustion engine is operated at a high altitude where the air is thin. In these cases, even if the internal combustion engine is started by the glow at start-up, there is a risk of misfire unless the subsequent afterglow is performed.

  It should be noted that as a countermeasure when a high temperature abnormality is determined at the time of afterglow, it is more desirable to reduce the duty ratio of energization than to shut off the energization to the switching element. This is because there is a risk of misfire if the current is cut off. In addition, when the temperature is abnormal, it is desirable to change the fuel injection timing so as to stabilize the combustion. In addition, regardless of whether or not there is a high temperature abnormality, it is desirable to avoid a high temperature abnormality while achieving combustion stability by reducing the amount of current supplied to the glow plug by the after glow from the amount of current supplied by the glow at start-up.

  A fifteenth aspect of the present invention is a glow plug control system comprising at least one of the glow plug and the filter device, and the glow plug control device. According to this glow plug control system, the above-described various effects can be similarly exhibited.

The figure for demonstrating the engine system of 1st Embodiment of this invention. The figure explaining the function of GDU shown in FIG. The figure explaining the hardware constitutions of GDU shown in FIG. The flowchart which shows the procedure of the high temperature abnormality determination process concerning 1st Embodiment. The flowchart which shows the procedure of the high temperature abnormality determination process concerning 2nd Embodiment of this invention. The timing chart which shows the command duty and energization signal by a 2nd embodiment. The block diagram which shows the some load apparatus concerning 3rd Embodiment of this invention. The timing chart which shows the instruction | command duty and diagnostic signal by 3rd Embodiment. In 3rd Embodiment, the timing chart which shows the command signal, energization signal, and diagnostic signal corresponding to each load apparatus. The flowchart which shows the procedure which controls the electricity supply state of each load apparatus in 3rd Embodiment. The timing chart which shows the command signal, energization signal, and diagnosis signal corresponding to each load apparatus in 4th Embodiment of this invention. The flowchart which shows the procedure which controls the electricity supply state of each load apparatus in 4th Embodiment. In 5th Embodiment of this invention, the timing chart which shows the command signal, energization signal, and diagnosis signal corresponding to each load apparatus. The flowchart which shows the procedure which controls the electricity supply state of each load apparatus in 5th Embodiment. In 6th Embodiment of this invention, the timing chart which shows the command signal, energization signal, and diagnosis signal corresponding to each load apparatus. The flowchart which shows the procedure which controls the electricity supply state of each load apparatus in 6th Embodiment. In 7th Embodiment of this invention, the timing chart which shows the command signal, energization signal, and diagnostic signal corresponding to each load apparatus. The flowchart which shows the procedure which controls the electricity supply state of each load apparatus in 7th Embodiment. The time chart explaining the control method in 8th Embodiment of this invention. The figure explaining the function of GDU in 9th Embodiment of this invention.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. In the present embodiment, the present invention is embodied as an engine system mainly composed of a diesel engine mounted on a vehicle, and a detailed configuration thereof will be described below. First, the overall configuration of the engine system according to the present embodiment will be described with reference to FIG.

  The intake passage 11 of the diesel engine 10 shown in FIG. 1 communicates with a combustion chamber 15 defined by a cylinder block 13 and a piston 14 by opening an intake valve 12. In the combustion chamber 15, a tip end portion of the fuel injection valve 16 protrudes so that fuel can be injected into the combustion chamber 15. When the fuel injected into the combustion chamber 15 by the fuel injection valve 16 is compressed in the combustion chamber 15, the fuel self-ignites to generate energy. This energy is taken out as rotational energy of the output shaft (crankshaft) 17 of the diesel engine 10 via the piston 14. On the other hand, the gas used for combustion is discharged into the exhaust passage 19 by opening the exhaust valve 18. The exhaust passage 19 is provided with a filter device (DPF device 19a) that collects particulate matter (PM) in the exhaust gas.

  Further, the tip of the glow plug 20 protrudes from the combustion chamber 15. A glow plug drive unit (hereinafter referred to as “GDU”) 30 is connected to the glow plug 20, and the GDU 30 interrupts energization from the battery 21 to the glow plug 20. When the diesel engine 10 is cold-started, the combustion chamber 15 is preheated by energizing the glow plug 20 to generate heat. Thereby, the initial ignitability of the air-fuel mixture in the combustion chamber 15 is improved. Note that the diesel engine 10 of the present embodiment has a plurality of cylinders, and the glow plug 20 is provided for each cylinder.

  A crank angle sensor 24 for detecting the rotation angle of the crankshaft 17 is provided in the vicinity of the crankshaft 17, and a water temperature sensor 25 for detecting the temperature of the cooling water of the diesel engine 10 is provided in the cylinder block 13. . The fuel injection valve 16, the crank angle sensor 24, the water temperature sensor 25, and the GDU 30 are connected to an ECU 40 (regeneration energization means).

  The ECU 40 is an electronic control unit mainly composed of a well-known microcomputer (microcomputer) provided with a CPU, a memory, etc., the memory stores various programs and parameters, and the CPU executes a program stored in the memory. Thus, each part of the diesel engine 10 is controlled. For example, by controlling the operation of the fuel injection valve 16, the fuel injection mode such as the fuel injection amount, the injection timing, and the number of injection stages in the case of performing the multi-stage injection injecting a plurality of times per one combustion cycle is controlled. Further, the operation of the glow plug 20 is controlled as will be described in detail later.

  Next, the configuration of the GDU 30 will be described with reference to FIG. In FIG. 2, the configuration other than the GDU 30 is indicated by a one-dot chain line. The GDU 30 includes a control IC 31 (energization control device) and a power element TR (switching element). Specific examples of the power element TR include power transistors such as a power MOSFET and an insulated gate bipolar transistor IGBT. A command signal output from the ECU 40 (command control device) is input to the control IC 31. This command signal is a duty signal for duty-controlling the glow plug 20, and the control IC 31 amplifies the command signal from the ECU 40 to generate an energization signal. The power element TR controls energization to the glow plug 20 by opening and closing a power supply path from the battery 21 to the glow plug 20 based on the energization signal output from the control IC 31.

  In this embodiment, a glow plug 20 is provided in each of the plurality of cylinders, and a power element TR is provided corresponding to these glow plugs 20, but in FIG. 2, one glow plug 20 and a power element are provided. TR is shown, and other glow plugs 20 and power elements TR are not shown.

  Next, the hardware configuration of the GDU 30 will be described with reference to FIG. The plurality of power elements TR and the control IC 31 are mounted on the metal plate 33 and are electrically connected by wire bonding. Of the various terminals T1 to T5 provided in the GDU 30, the terminal T2 is electrically connected to the metal plate 33 by wire bonding. A terminal T3 is electrically connected to the power element TR by wire bonding. A battery 21 is connected to the terminal T2, and a glow plug 20 is connected to each of the terminals T3. Therefore, the electric power supplied from the battery 21 is supplied to each glow plug 20 through the terminal T2, the metal plate 33, the power element TR, and the terminal T3. The terminal T5 supplies power from the battery 24 to the control IC 31.

  The plate member 33 also functions as a heat radiating plate that dissipates heat generated by the power element TR and the control IC 31, and is disposed on the surface of the plate member 33 opposite to the control IC 31 (the back side in FIG. 3). A heat sink (heat radiating means) (not shown) may be attached.

  The control IC 31 is electrically connected to the terminals T1 and T4 by wire bonding. A command signal from the ECU 40 is input to the control IC 31 through the terminal T1, and a diagnosis signal from the control IC 31 is output from the terminal T4 to the ECU 40.

  A temperature sensitive element 32 (temperature detecting means) for detecting the temperature of the power element TR is attached on the chip of the power element TR. Specific examples of the temperature sensitive element 32 include a thermal diode and a thermistor. Each temperature sensing element 32 is electrically connected to the control IC 31 by wire bonding.

  The power element TR, the control IC 31, the metal plate 33, the temperature sensing element 32 as a whole and a part of the terminals T1 to T5 are bonded by a resin member 34. In FIG. 3, the state which cut | disconnected the resin member 34 is shown in the cross-section part which attached | subjected hatching. The resin member 34 prevents each of the bonded parts from being short-circuited due to adhesion of moisture or foreign matter.

  With the above configuration, when the diesel engine 10 is cold started, the ECU 40 outputs a command signal so that the glow plug 20 is energized. Hereinafter, the energization to the glow plug 20 for assisting the initial ignitability at the cold start in this way is referred to as cold assist energization. The energization of the glow plug 20 during the DPF regeneration process described below is referred to as DPF regeneration energization. It is assumed that energization during DPF regeneration is executed for about 30 minutes.

  Here, in the DPF device 19a, a regeneration process is required for burning the PM when the collected PM exceeds a predetermined amount. Therefore, fuel injection control is performed to forcibly raise the exhaust gas temperature (for example, 500 ° C. to 650 ° C.) and forcibly remove the collected PM by performing post injection after main injection when injecting fuel. ing. The main injection and the post injection are one of a plurality of injections during one combustion cycle. The main injection is an injection that contributes to the rotational drive of the output shaft 17, and the post injection is the main injection. This is an injection that is injected after the injection and contributes to the temperature rise of the exhaust gas.

  In the regeneration processing of the present embodiment, the exhaust gas is heated by increasing the main injection amount separately from the execution of such post injection. However, if the main injection amount is simply increased, the engine speed (NE) increases, which gives the driver a feeling of strangeness. In particular, at the time of NE low speed such as during idling, there is a great sense of incongruity due to NE increase.

  Accordingly, in the present embodiment, attention is paid to the fact that the battery 21 is charged by using the output shaft 17 as a drive source, and if the electric load to the battery 21 is increased, the NE increase while increasing the main injection amount. We focus on the point that can be suppressed. In other words, during the regeneration process for increasing the main injection amount, the glow plug 20 is driven to increase the electrical load on the battery 21, thereby suppressing an increase in NE while increasing the main injection amount. Note that the microcomputer of the ECU 40 that controls the energization of the glow plug 20 so as to increase the electrical load on the battery 21 during the regeneration process corresponds to “a regeneration energizing unit”.

  However, since the temperature of the combustion chamber 15 is high during such regeneration processing, if the power element TR generates heat by energizing the glow plug 20, there is a concern that the temperature of the power element TR exceeds the heat resistance temperature. Therefore, in this embodiment, in order to avoid damage due to heat generation of the power element TR, a determination process is performed as to whether or not the power element TR is abnormally hot as shown in FIG.

  This determination process is a process that is repeatedly executed by a microcomputer provided in the control IC 31 or the GDU 30 at a predetermined cycle (for example, the calculation processing cycle of the control IC 31). First, in step S10, whether or not the power element TR is energized. Is determined based on the energization signal output from the control IC 31 to the power element TR. If it is determined that power is being supplied (S10: YES), the process proceeds to step S20 (determination means), and the temperature of the power element TR is preset based on the detected temperature signal input from the temperature sensing element 32 to the control IC 31. It is determined whether or not the temperature has exceeded a threshold value (predetermined temperature).

  If it is determined that the threshold has been exceeded (S20: YES), the process proceeds to step S30 (determination means), and it is determined whether or not the time exceeding the threshold has continued for a predetermined time tfil (filter time) set in advance. . If it is determined that it has continued for a predetermined time tfil or longer (S30: YES), it is determined that the power element TR is in a high temperature abnormal state, and the process proceeds to step S40 (energization limiting means) to stop energizing the power element TR. The energization signal is forcibly switched off. In addition, the determination process of step S10, S20, S30 is a process performed about each of several power element TR, and electricity supply is stopped only about the power element TR of a corresponding channel in step S40.

  In subsequent step S50, a diagnostic signal indicating that the energization signal is switched off is output from the control IC 31 to the ECU 40 against the command signal. Thereafter, in step S60, it is determined whether or not the temperature of the power element TR has fallen below a threshold value. If it is determined that the threshold value has been fallen below (S60: YES), the process proceeds to step S70, where energization to the power element TR of the channel that has been forcibly stopped is resumed and energization is resumed in the subsequent step S80. A diagnosis signal is output from the control IC 31 to the ECU 40.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) Since the temperature (element temperature) of the power element TR is directly detected by the temperature sensing element 32, an accurate element temperature can be obtained from the current value flowing through the power element TR as compared with the conventional control that assumes the element temperature. Therefore, since it is unnecessary to provide a margin for the heat resistance performance required for the power element TR, it is possible to reduce the heat resistance performance or the heat radiation capability required for the heat radiation means such as a heat sink.

  In particular, when the glow plug 20 is energized not only during cold start but also during the DPF regeneration process as in this embodiment, a current is passed through the power element TR in an extremely high ambient temperature to energize the glow plug 20. Therefore, there is a concern about abnormal high temperature of the power element TR. Therefore, as described above, the above-described effect that the required heat resistance performance and heat dissipation capability can be reduced is preferably exhibited.

  (2) When a large inrush current flows as in the glow plug 20, if the conventional control assuming the element temperature from the current value flowing through the power element TR is performed, the current threshold value for determining the high temperature abnormality is adjusted to the inrush current. Need to be expensive. However, if a failure (such as a rare short) in which a current slightly lower than this threshold flows continuously occurs, it is not determined that the temperature is abnormal in current detection, but the power element TR may be damaged due to a high temperature. There is sex. In this embodiment, since the element temperature is directly detected in order to deal with such a problem of a rare short circuit failure, even if a rare short circuit failure occurs, the power element TR is accurately determined to stop energization. be able to.

  (3) When the temperature of the power element TR exceeds the threshold, it is determined that the power element TR is in a high temperature abnormal state only after the time exceeding the threshold has continued for a predetermined time tfil or longer. Therefore, it is possible to avoid erroneous determination due to the temperature of the power element TR exceeding the threshold due to noise.

(Second Embodiment)
In the first embodiment, when the high temperature abnormality is determined, the energization amount to the glow plug 20 is limited by turning off the energization signal to the power element TR to cut off the energization. When a high temperature abnormality is determined, the duty (energization duty) of the energization signal output from the control IC 31 to the power element TR is reduced, contrary to the duty (command duty) of the command signal output from the ECU 40 to the control IC 31. By reducing the energization amount, the amount of energization per unit time is limited to be within a predetermined value.

  Specifically, the determination processing procedure of FIG. 4 is changed to the procedure of FIG. That is, first, similarly to steps S10 to S30 in FIG. 4, it is determined whether or not the power element TR is energized (step S10), and whether or not the temperature of the power element TR exceeds the threshold value (step S20). ) And whether or not the time exceeding the threshold value has continued for a predetermined time tfil or more (step S30) is sequentially executed.

  Next, when it is determined that it has continued for a predetermined time tfil or longer (S30: YES), it is determined that the power element TR is in a high temperature abnormality state, and the process proceeds to step S50, and a diagnosis signal indicating that the high temperature abnormality has been determined. And output from the control IC 31 to the ECU 40. In subsequent step S61 (energization limiting means), the duty ratio (see FIG. 6B) to the power element TR of the corresponding channel determined to be abnormal in high temperature is changed to a basic duty (FIG. 6A) based on the command signal. ) Refer to)). In addition, the code | symbol t10 in FIG. 6 shows the time of determining with high temperature abnormality.

  In a succeeding step S62, it is determined whether or not the temperature of the power element TR has fallen below a threshold value. If it is not below the threshold (S62: NO), the process returns to step S61, and the energization duty is further reduced. When it is determined that the threshold value is below the threshold (S62: YES), the process proceeds to step S63, and the energization duty to the power element TR of the channel determined to be abnormal in high temperature is increased from the current energization duty.

  In a succeeding step S64, it is determined whether or not the temperature of the power element TR has exceeded the threshold value. If it is determined that the threshold value is exceeded (S64: YES), the process returns to step S61, and the energization duty to the power element TR of the corresponding channel determined to be abnormal in high temperature is decreased again. On the other hand, when it is determined that the threshold value is not exceeded (S64: NO), in step S65, it is determined whether or not the energization duty that has been decreased has returned to the basic duty of the command signal. In the case (S65: YES), a diagnostic signal indicating normal rather than high temperature abnormal state is output from the control IC 31 to the ECU 40.

  As described above, even in the present embodiment in which the duty of energization to the power element TR is reduced when the temperature is abnormal, since the temperature of the power element TR is directly detected by the temperature sensing element 32, the same effect as in the first embodiment is exhibited. The

(Third embodiment)
In each of the above embodiments, it is assumed that only the glow plug 20 is energized as an electrical load on the battery 21 during the DPF regeneration process. On the other hand, in this embodiment shown in FIG. 7, the glow plug 20 is the first load device, and the second load device 202 and the third load device 203 are also energized during the DPF regeneration process. Specific examples of the second load device 202 and the third load device 203 include an electric heater (intake heater) that heats the intake air drawn into the combustion chamber, an electric heater (seat heater) that heats the passenger seat of the vehicle, and a rear An electric heater (windshield heater) attached to the windshield, an electric fan of a radiator, etc. may be mentioned.

  The first control IC 31 in FIG. 7 is the same as the control IC 31 shown in FIG. 2, and the second and third control ICs 302 and 303 are based on the command signal from the ECU 40 and the second and third load devices 202. , 203 is outputted to the second and third load devices 202, 203 to control the energization of the second load device 202, 203.

  FIG. 8A shows a change in state of the command duty input from the ECU 40 to the first control IC 31, and FIG. 8B shows details of a diagnosis signal output from the first control IC 31 to the ECU 40. As shown in FIG. 8B, the diagnostic signal includes signals for four glow plugs 20 in one serial signal, bit number 0 represents a start bit, bit number 9 represents a stop bit, and immediately after the start bit. The high temperature abnormality signals for the four power elements TR are assigned in order. In the example shown in FIG. 8B, since the bit numbers 1 to 4 are at a high level, it can be seen that all four power elements TR are determined to be in a high temperature abnormal state.

  Here, in each of the above embodiments, when a high temperature abnormal state is detected, the duty signal is reduced or turned off against the command signal. However, as shown in FIG. It may be reduced or turned off. In the example of FIG. 8A, the duty for the next command signal is decreased based on the high level of bit numbers 1 to 4 in the diagnosis signal.

  FIGS. 9B, 9E, and 9G show energization signals output from the first to third control ICs 31, 302, and 303 to the first to third load devices 20, 202, and 203, respectively. (A) (d) (f) shows the command signal output from ECU40 with respect to 1st-3rd control IC31,302,303, FIG.9 (c) is output to ECU40 from 1st control IC31. The high temperature abnormality signal in the displayed diagnostic signal is shown. In addition, command signals, energization signals, and diagnosis signals are also shown in FIGS. 11, 13, 15, and 17 (a) to (g) used in the description of the following embodiments in the same manner as in FIG. 9, 11, 13, 15, and 17 indicate the energized state of the load devices 20, 202, and 203 during the DPF regeneration process when the abnormal high temperature state is not detected.

  In the present embodiment, as shown in FIG. 9, at time t0 when the DPF regeneration processing is started, the command signal is switched from the energized off state to the on state so that all the load devices 20, 202, 203 are energized. Thereafter, when the above-described high-temperature abnormal state is detected for the power element TR of the glow plug 20 that is the first load device, an abnormal signal is set in the diagnosis signal at time t10 (see FIG. 9C).

  When a high temperature abnormality is detected, the duty ratio for the corresponding power element TR is reduced (see FIG. 9B), and at the same time, the second and third load devices 202 and 203 are compensated to compensate for the decrease. Increase the command duty. As a result, it is possible to secure a sufficient amount of electric load to suppress an increase in NE when the main injection amount is increased with the DPF regeneration process. Thereafter, at time t20 when the DPF regeneration process is finished, the command signal is switched to the energization off state so that all the load devices 20, 202, 203 are energized off.

  In addition, the dotted line in FIG. 9 shows the energization state of the load devices 20, 202, 203 during the DPF regeneration process when the high temperature abnormal state is not detected.

  Next, in controlling the energization state of the load devices 20, 202, 203 as described above, the control procedure will be described based on the flowchart of FIG.

  The process of FIG. 10 is a process that is repeatedly executed at a predetermined cycle by a microcomputer provided in the ECU 40. First, in step S100, it is determined whether or not the DPF regeneration energization period is in progress. If it is determined that the energization period is during DPF regeneration (S100: YES), in the subsequent step S101, a command signal for energizing the glow plug 20 (hereinafter referred to as an “energization command”) is provided in the first control IC 31. Send to.

  In a succeeding step S105, it is determined whether or not the power element TR has a high temperature abnormality. In this determination, the ECU 40 may acquire a detected temperature signal input from the temperature sensing element 32 to the control IC 31, and the microcomputer of the ECU 40 may determine a high temperature abnormality based on the detected temperature signal. Alternatively, the first control IC 31 may determine a high temperature abnormality based on the detected temperature signal and transmit it as a diagnosis signal to the ECU 40, and the microcomputer of the ECU 40 may acquire a determination result of the high temperature abnormality included in the diagnosis signal. .

  If it is determined that the temperature is not abnormal (S105: NO), in the subsequent step S110, a second normal energization command for energizing the second load device 202 with a preset normal energization amount is set to the second. It transmits to control IC302. In step S <b> 111, a normal energization command for energizing the third load device 203 with a preset normal energization amount is transmitted to the third control IC 303.

  Here, apart from the main process shown in FIG. 10, the process shown in FIG. 5 is executed by the first control IC 31. Therefore, when a high temperature abnormality occurs, the duty of energizing the glow plug 20 is reduced from the basic duty based on the command signal by the process of step S61 in FIG. If it is determined in this process that the temperature is abnormal (S105: YES), the amount of reduction that is reduced with respect to the basic duty is acquired from the first control IC 31 in step S120. For example, the first control IC 31 transmits the decrease amount to the ECU 40 as a diagnosis signal, so that the ECU 40 can acquire the decrease amount.

  In the subsequent step S121, the energization increase amount for the second load device 202 and the third load device 203 is calculated based on the energization decrease amount acquired in step S120. This energization increase amount is set without excess or deficiency to compensate for the energization decrease amount. For example, it is desirable to set the energization increase amount in the range of 100 W to 400 W or in the range of 25 W to 400 W, assuming that the energization amount to all the glow plugs 20 becomes zero.

  In the subsequent step S130, an increase energization command for energizing the second load device 202 with the energization amount increased by the energization increase amount with respect to the normal energization amount is transmitted to the second control IC 302. In step S131, an increase energization command for energizing the third load device 203 with the energization amount increased by the energization increase amount with respect to the normal energization amount is transmitted to the third control IC 303. .

  Next, in step S170, it is determined whether or not it is time to end the DPF regeneration process and end energization during DPF regeneration. If it is determined that it is the end timing of energization during DPF regeneration (S170: YES), in the subsequent step S180, an energization stop command for stopping energization of each load device 20, 202, 203 is issued to each control IC 31, 302, To 303. If it is determined that it is not the end timing of energization during DPF regeneration (S170: NO), or if it is determined in step S100 that it is not an energization period during DPF regeneration (S100: NO), the process proceeds to step S100. Return.

  As described above, according to the present embodiment, the same effects as those of the above-described embodiments are exhibited, and when the high temperature abnormality occurs during the DPF regeneration process, the energization amount to the glow plug 20 is reduced. Thus, thermal damage to the power element TR due to energization of the glow plug 20 can be avoided. Further, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is decreased, the decrease amount is increased by increasing the energization amounts of the other load devices 202 and 203. Therefore, the increase in NE during the DPF regeneration process can be sufficiently suppressed.

(Fourth embodiment)
In the third embodiment, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is reduced, the decrease is compensated by increasing the energization amounts of the load devices 202 and 203. In this case, the energization amounts of the plurality of load devices 202 and 203 are simultaneously increased. On the other hand, in this embodiment, the energization amount increase to the 2nd and 3rd load apparatus 202,203 is performed alternately.

  More specifically, referring to FIG. 11, first, at time t0 when the DPF regeneration process is started, the command signal is switched from the energized off state to the on state so as to energize all the load devices 20, 202, and 203. . Thereafter, when the above-described high-temperature abnormal state is detected for the power element TR of the glow plug 20 that is the first load device, an abnormal signal is set in the diagnosis signal at time t10 (see FIG. 11C).

  When a high temperature abnormality is detected, the current supply duty for the corresponding power element TR is decreased (see FIG. 11B), and at the same time, the command duty for the second load device 202 is increased to compensate for the decrease. . Thereafter, at time t11, the command duty for the second load device 202 is returned to the normal value, and the command duty for the third load device 203 is increased. As a result, it is possible to secure a sufficient amount of electric load to suppress an increase in NE when the main injection amount is increased with the DPF regeneration process. Thereafter, at time t20 when the DPF regeneration process is finished, the command signal is switched to the energization off state so that all the load devices 20, 202, 203 are energized off.

  Next, in controlling the energization state of the load devices 20, 202, 203 as described above, the control procedure will be described based on the flowchart of FIG.

  The process in FIG. 12 is a process that is repeatedly executed at a predetermined cycle by a microcomputer provided in the ECU 40. First, in steps S100 to S121, the same process as in FIG. 10 is executed. In other words, if it is determined that the energization period is during DPF regeneration (S100: YES), an energization command for energizing the glow plug 20 is transmitted to the first control IC 31 (S101). And when it determines with it not being a high temperature abnormal state (S105: NO), a normal electricity supply command is transmitted to the 2nd control IC302 and the 3rd control IC303 (S110, S111). On the other hand, if it is determined that the temperature is abnormal (S105: YES), a decrease in energization for the glow plug 20 is acquired (S120), and the second load device 202 and the third load are obtained based on the acquired decrease in energization. An energization increase amount for the device 203 is calculated (S121).

  Next, in step S125, it is determined whether or not it is an energization increasing period for the second control IC 302 set as a period for increasing energization to the second load device 202. If it is determined that it is the energization increase period for the second control IC 302 (S125: YES), in the subsequent step S130, the energization amount increased by the energization increase amount with respect to the normal energization amount. An increase energization command for energizing the 2-load device 202 is transmitted to the second control IC 302. On the other hand, if it is determined that it is not the energization increase period for the second control IC 302 (S125: NO), in the subsequent step S131, the energization amount increased by the energization increase amount with respect to the normal energization amount. An increase energization command for energizing the third load device 203 is transmitted to the third control IC 303.

  Next, in step S170, it is determined whether or not it is time to end the DPF regeneration process and end energization during DPF regeneration. If it is determined that it is the end timing of energization during DPF regeneration (S170: YES), in the subsequent step S180, an energization stop command for stopping energization of each load device 20, 202, 203 is issued to each control IC 31, 302, To 303. When it is determined that it is not the end timing of energization during DPF regeneration (S170: NO), or when it is determined that it is not during the energization period during DPF regeneration (S100: NO), the processing of step S100 is performed. Return. As described above, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process, the energization amount to the glow plug 20 is reduced. Therefore, the heat of the power element TR caused by energizing the glow plug 20 in a high temperature environment. Damage can be avoided. Further, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is reduced, the decrease amount is alternately used by the energization amounts of the other load devices 202 and 203. Therefore, the increase in NE during the DPF regeneration process can be sufficiently suppressed.

(Fifth embodiment)
In the second to fourth embodiments, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is decreased, the decrease amount is increased by increasing the energization amount of the load devices 202 and 203. I make up for that. On the other hand, in the present embodiment, as shown in FIG. 13, when a high temperature abnormality is detected (see t10), the execution of the DPF regeneration process is temporarily stopped and all the load devices 20, 202, 203 are transferred. Is turned off (see t12). Hereinafter, in controlling the energization state of the load devices 20, 202, 203 as described above, the control procedure will be described based on the flowchart of FIG.

  The process of FIG. 14 is a process that is repeatedly executed at a predetermined cycle by a microcomputer provided in the ECU 40. First, in step S100, it is determined whether or not the DPF regeneration energization period is in progress. If it is determined that the energization period is during DPF regeneration (S100: YES), in the subsequent step S102, a command signal (energization command) for energizing all the load devices 20, 202, 203 is sent to each 1 to the third control ICs 31, 302, 303 are transmitted.

  If it is determined in the subsequent step S105 that the high temperature abnormality is not occurring (S105: NO), the energization command transmission in step S102 is performed until it is determined in the subsequent step S170 that it is the end timing of energization during DPF regeneration. If it is determined that it is the end timing of energization during DPF regeneration (S170: YES), in the subsequent step S180, an energization stop command for stopping energization of each load device 20, 202, 203 is issued to each control IC 31,302. , 303.

  On the other hand, if it is determined that the temperature is abnormal (S105: YES), in the subsequent step S140, a command signal (energization stop command) for stopping energization of all the load devices 20, 202, 203 is provided. To the first to third control ICs 31, 302, 303.

  As described above, according to the present embodiment, since the energization to the glow plug 20 is stopped when a high temperature abnormality occurs during the DPF regeneration process, the thermal damage to the power element TR caused by energizing the glow plug 20 in a high temperature environment. Can be avoided. In addition, when a high temperature abnormality occurs during the DPF regeneration process, the execution of the DPF regeneration process is temporarily stopped, so that the energization amount to the glow plug 20 is reduced or the energization is stopped while continuing the DPF regeneration process. Thus, the temperature of the power element TR (element temperature) can be quickly reduced.

(Sixth embodiment)
In the second to fourth embodiments, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is decreased, the decrease amount is increased by increasing the energization amount of the load devices 202 and 203. I make up for that. On the other hand, in this embodiment shown in FIG. 15, the energization period to all the load devices 20, 202, 203 is extended to t21 as compared with the case where no high temperature abnormality has occurred.

  Hereinafter, the control procedure for controlling the energization state of the load devices 20, 202, 203 as described above will be described with reference to the flowchart of FIG.

  The process of FIG. 16 is a process repeatedly executed at a predetermined cycle by a microcomputer provided in the ECU 40. First, in step S100, it is determined whether or not it is during a period for energization during DPF regeneration. If it is determined that the energization period is during DPF regeneration (S100: YES), in the subsequent step S102, a command signal (energization command) for energizing all the load devices 20, 202, 203 is sent to each 1 to the third control ICs 31, 302, 303 are transmitted.

  If it is determined in the subsequent step S105 that the high temperature abnormality is not occurring (S105: NO), the energization command transmission in step S102 is performed until it is determined in the subsequent step S170 that it is the end timing of energization during DPF regeneration. If it is determined that it is the end timing of energization during DPF regeneration (S170: YES), in the subsequent step S180, an energization stop command for stopping energization of each load device 20, 202, 203 is issued to each control IC 31,302. , 303.

  On the other hand, when it is determined that the temperature is abnormal (S105: YES), in the subsequent step S120, the energization reduction amount for the glow plug 20 is acquired from the first control IC 31 in the same manner as in step S120 of FIG. In the subsequent step S150, the energization extension time for the second load device 202 and the third load device 203 is calculated based on the decrease in energization acquired in step S120. Then, the timing for ending the DPF regeneration process and ending the energization during DPF regeneration is updated so as to be delayed by the calculated extension time. That is, the energization end timing used for the determination in step S170 is delayed. When extending the DPF regeneration processing time in this way, when forcibly raising the temperature of the exhaust gas, the temperature rise amount is reduced by, for example, reducing the main injection amount to promote the temperature drop of the power element TR. It is desirable.

  As described above, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process, the energization amount to the glow plug 20 is reduced. Therefore, the heat of the power element TR caused by energizing the glow plug 20 in a high temperature environment. Damage can be avoided. In addition, the DPF regeneration processing time is extended according to the decrease in the energization amount to the glow plug 20, and the energization period to the other load devices 202 and 203 is extended along with the extension, so that the NE increase suppression during the DPF regeneration processing is suppressed. We can plan enough.

(Seventh embodiment)
In the second to sixth embodiments, during the DPF regeneration process, the NE increase is suppressed by energizing all the load devices 20, 202, 203. On the other hand, in the present embodiment shown in FIG. 17, during the DPF regeneration process, only the glow plug 20 is energized and the other load devices 202 and 203 are energized off. When a high temperature abnormality is detected at time t10, energization to the other load devices 202 and 203 is turned on.

  Hereinafter, in controlling the energization state of the load devices 20, 202, 203 as described above, the control procedure will be described based on the flowchart of FIG.

  The process in FIG. 18 is a process that is repeatedly executed at a predetermined cycle by a microcomputer provided in the ECU 40. First, in steps S100 to S105, S120, and S121, the same process as in FIG. 10 is executed. In other words, if it is determined that the energization period is during DPF regeneration (S100: YES), an energization command for energizing the glow plug 20 is transmitted to the first control IC 31 (S101). And when it determines with it being high temperature abnormality (S105: YES), the energization reduction amount with respect to the glow plug 20 is acquired (S120), and 2nd load apparatus 202 and 3rd load are based on the acquired energization reduction amount. The energization amount for the device 203 is calculated (S121). This energization amount is set without excess or deficiency to compensate for the decrease in energization.

  Next, in step S160, an energization command for energizing the second load device 202 with the energization amount calculated in step S121 is transmitted to the second control IC 302. In subsequent step S161, an energization command for energizing the third load device 203 with the energization amount calculated in step S121 is transmitted to the third control IC 303.

  Thereafter, in step S170, it is determined whether or not it is time to end the DPF regeneration process and end energization during DPF regeneration. If it is determined that it is the end timing of energization during DPF regeneration (S170: YES), in the subsequent step S180, an energization stop command for stopping energization of each load device 20, 202, 203 is issued to each control IC 31, 302, To 303. If it is determined that it is not the end timing of energization during DPF regeneration (S170: NO), or if it is determined in step S100 that it is not an energization period during DPF regeneration (S100: NO), the process proceeds to step S100. Return.

  On the other hand, when it is determined in step S105 that the temperature is not abnormal (S105: NO), the process of step S170 is performed without transmitting the energization command to the second and third control ICs 302 and 303 as in steps S160 and S161. Proceed to That is, when the temperature is not abnormal, the second and third load devices 202 and 203 are not energized even during the DPF regeneration energization period.

  As described above, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process, the energization amount to the glow plug 20 is reduced. Therefore, the heat of the power element TR caused by energizing the glow plug 20 in a high temperature environment. Damage can be avoided. Further, according to the present embodiment, when a high temperature abnormality occurs during the DPF regeneration process and the energization amount to the glow plug 20 is reduced, the reduced amount is energized to the other load devices 202 and 203. Since it compensates, NE rise suppression at the time of DPF regeneration processing can fully be aimed at. Furthermore, according to the present embodiment, when the high temperature abnormality is not occurring, the second and third load devices are prohibited from energizing the second and third load devices 202 and 203 even during the DPF regeneration energization period. It can be avoided that the drivers 202 and 203 operate at a timing unintended by the occupant to give the driver an uncomfortable feeling.

(Eighth embodiment)
In each of the above embodiments, when the glow plug 20 is energized during the DPF regeneration process, the duty ratio of the energization signal output from the control IC 31 to the power element TR rapidly increases, for example, in a step shape at time t0 in FIG. I am letting. When the duty ratio is rapidly increased in this way (see FIG. 19B), the power consumption in the glow plug 20 increases for several seconds due to the inrush current to the glow plug 20 (see FIG. 19A). . However, when the glow plug 20 is energized at the time of executing the regeneration process as described above, if the power consumption increases due to the inrush current, the magnitude of the electric load will fluctuate. In order to suppress the increase, NE will be fluctuated.

  On the other hand, in the present embodiment, when energization to the glow plug 20 is started with the execution of the regeneration process (at time t0 in FIG. 19), the duty ratio of energization to the power element TR is gradually increased (FIG. 19 ( d)). Thereby, the power consumption in the glow plug 20 can be set to a constant value without fluctuation from the energization start time t0 to the energization end time t20 due to the inrush current (see FIG. 19C). As described above, when gradually increasing the duty ratio, the power consumption at the glow plug 20 may be gradually increased in a preset pattern so as to be constant, or may be increased with a predetermined time constant. It may be.

  As described above, according to the present embodiment, when the glow plug 20 is energized during the regeneration process, it is possible to avoid fluctuations in the magnitude of the electric load, and to solve the above-described NE fluctuation problem.

(Ninth embodiment)
In the first embodiment, the “regeneration energization means” that controls energization of the glow plug 20 so as to increase the electrical load on the battery 21 when the regeneration process is executed is configured by a microcomputer provided in the ECU 40. That is, the microcomputer of the ECU 40 instructs the glow plug 20 to be energized when executing the regeneration process. On the other hand, in this embodiment shown in FIG. 20, the microcomputer 35 provided in the GDU 30 constitutes a power supply means during reproduction. That is, the microcomputer 35 of the GDU 30 instructs the glow plug 20 to be energized when the reproduction process is executed.

  In the first embodiment, the energization limiting means for controlling the energization to the power element TR based on the temperature signal detected by the temperature sensing element 32 is configured by the control IC 31 that executes step S40 in FIG. Yes. Then, the fact that the restriction is made is transmitted to the ECU 40 as a diagnosis signal. On the other hand, as shown in FIG. 20, the detected temperature signal input to the control IC 31 is acquired as a diagnostic signal by the microcomputer 35 of the GDU 30, and the microcomputer 35 of the GDU 30 energizes the power element TR based on the acquired detected temperature signal. A command signal may be output so as to stop.

  In short, the process executed by the microcomputer of the ECU 40 in the first embodiment is executed by the microcomputer 35 provided in the GDU 30 in the present embodiment.

(Other embodiments)
The above embodiments may be implemented with the following modifications. Further, the present invention is not limited to the description of the above embodiment, and the characteristic structures of the embodiments may be arbitrarily combined.

  In each of the above embodiments, the temperature sensitive element 32 is attached to the power element TR, but the present invention is not limited to this, and may be attached to the control IC 31 or the metal plate 33, for example. When the temperature sensing element 32 is attached to the control IC 31, the wire bonding for connecting the control IC 31 and the temperature sensing element 32 can be eliminated. Further, when the temperature sensitive element 32 is attached to the power element TR, it is possible to determine whether or not each of the plurality of power elements TR has a high temperature abnormality.

  When the high temperature abnormality is detected at the time of starting the DPF regeneration process or when the DPF regeneration process is detected, the DPF regeneration process is temporarily stopped, and after a predetermined time has elapsed, the temperature of the power element TR is lowered, and then the DPF is again performed. You may make it perform reproduction | regeneration processing.

  -In energizing the load devices 20, 202, 203 during DPF regeneration, it is desirable to reduce the energization amount compared to energization when the load devices 20, 202, 203 are used for original purposes other than during DPF regeneration. . According to this, for example, when the load devices 202 and 203 are electric fans or the like, it is possible to reduce noise caused by the operation of the load devices 202 and 203 during DPF regeneration and to reduce discomfort to the passengers.

  In the above-described embodiment shown in FIG. 1, the DPF device 19a is applied as the purification device. However, in addition to the DPF device 19a, the NOx catalyst that purifies NOx in the exhaust, and the oxidation that purifies HC and CO in the exhaust. A catalyst etc. are mentioned. Since these catalysts function in a state of being activated at a high temperature, the load devices 20, 202, and 203 are energized as a NE increase suppression when the main injection amount is increased not in the regeneration process but in the activation process. .

  In the above embodiment, in addition to energizing the glow plug 20 for assisting the initial ignitability at the start of the diesel engine 10 (glow at start), the glow plug 20 is energized when the regeneration process is executed. In addition to energization of the glow plug 20 at the time of executing the regeneration process, after glow described below may be performed. That is, when applied to a diesel engine 10 with a low compression ratio, or when the diesel engine 10 is operated at a high altitude where the air is thin, even if the diesel engine 10 is started by starting glow, the subsequent operation of the glow plug 20 is performed. Stopping may cause misfire. Therefore, after the start-up glow is performed for a predetermined period (for example, about 5 minutes), the glow plug 20 is operated (after-glow) so as to stabilize combustion also in a predetermined post-start period (for example, about 5 to 10 minutes). desirable.

  In the above embodiment, the temperature (element temperature) of the power element TR is directly detected by the temperature sensing element 32, and it is determined whether or not there is a high temperature abnormality based on the detected temperature signal from the temperature sensing element 32. The temperature sensor 32 is not limited to such a configuration. For example, a detection circuit that detects an energization amount to the glow plug 20 is provided, and it is determined whether or not there is a high temperature abnormality based on the detected energization amount. It may be.

  DESCRIPTION OF SYMBOLS 10 ... Diesel engine (internal combustion engine), 15 ... Combustion chamber, 20 ... Glow plug (1st load apparatus), 31 ... Control IC (energization control apparatus), 32 ... Temperature sensing element (temperature detection means), 40 ... ECU ( Command control device, regeneration energization means), 202 ... second load equipment (other load equipment), 203 ... third load equipment (other load equipment), S20, S30 ... (determination means), S40, S61 ... energization Limiting means, TR ... power element (switching element).

Claims (15)

Applied to an internal combustion engine comprising a glow plug provided in a combustion chamber of an internal combustion engine and a filter device for collecting particulate matter in exhaust gas,
When the regeneration process is executed to increase the exhaust temperature so as to remove the collected particulate matter from the filter device, the load device is energized to increase the electrical load to the battery charged using the internal combustion engine as a drive source. It has a means for energizing during playback,
The glow plug control device, wherein the glow plug is energized when the internal combustion engine is started, and is also energized when the regeneration process is performed as the load device. A switching element for turning on and off the energization of the glow plug;
An energization controller for controlling the operation of the switching element;
Determining means for determining whether or not the temperature of the switching element is in a high temperature abnormality state where the temperature is equal to or higher than a predetermined temperature;
With
The glow plug control device according to claim 1, further comprising an energization limiting unit configured to limit an energization amount to the glow plug when the determination unit determines that the high temperature abnormality has occurred. Comprising temperature detecting means for detecting the temperature of the switching element;
The glow plug control device according to claim 2, wherein the determination unit determines whether or not the high temperature abnormality is based on the temperature detected by the temperature detection unit. The regeneration energizing means is
While performing energization control at the time of the regeneration process execution for a plurality of load devices including the glow plug,
4. The glow plug control device according to claim 2, wherein an energization amount to other load devices excluding the glow plug is increased as compared with a normal time when the high temperature is abnormal. 5. There are a plurality of other load devices,
The glow plug control device according to claim 4, wherein the regeneration energizing means simultaneously increases energization amounts to the plurality of other load devices when the high temperature is abnormal. There are a plurality of other load devices,
The regeneration energization means alternately increases the energization amount to the plurality of other load devices so as to increase the energization amount to any one of the other load devices at the time of the high temperature abnormality. The glow plug control device according to claim 4, wherein   The glow plug according to any one of claims 4 to 6, wherein the regeneration energization means prohibits the energization of the other load device at the normal time even when the regeneration process is executed. Control device.   The glow plug control device according to any one of claims 2 to 7, wherein the regeneration energization means lengthens the energization time of the load device when the high temperature is abnormal and when normal.   The glow plug control device according to claim 2 or 3, wherein execution of the regeneration process is postponed when the high temperature is abnormal.   The energization limiting unit limits the energization amount by interrupting energization to the switching element or reducing a duty ratio of energization. Glow plug control device.   The energization control device controls the operation of the switching element based on a command signal output from the command control device, and executes energization limitation by the energization limiting means against the command content of the command signal. The glow plug control device according to any one of claims 2 to 10, wherein a diagnosis signal notifying the execution is output to the command control device. The glow plug is provided in each of the plurality of cylinders of the internal combustion engine,
The glow plug control device according to claim 11, wherein the energization control device outputs the diagnosis signal for each of the glow plugs. A switching element for turning on and off the energization of the glow plug;
The glow plug according to claim 1, wherein when energization of the glow plug is started as the regeneration process is executed, a duty ratio of energization to the switching element is gradually increased. Control device.   2. The glow plug is energized to assist initial ignitability at the start of the internal combustion engine and energized to stabilize combustion even during a period after the internal combustion engine is started. The glow plug control device according to any one of ˜13. At least one of the glow plug and the filter device;
A glow plug control device according to any one of claims 1 to 14,
A glow plug control system comprising:

Images