JP2009047134A - Device for controlling current-carrying amount of glow plug of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for controlling current-carrying of a glow plug of an internal combustion engine capable of extending the life of the glow plug. <P>SOLUTION: This device for controlling the current-carrying of the glow plug is provided with the glow plug, a power supply means supplying power to the glow plug, a glow plug current-carrying amount control means controlling the temperature of the glow plug by controlling the current-carrying amount to the glow plug, a storage means storing a historical pattern of the current-carrying of the glow plug, and a glow plug remaining life calculating means calculating the remaining life of the glow plug based on the current-carrying historical pattern upon a request of passing a current through the glow plug. The glow plug current-carrying amount control means adjusts the current-carrying amount to the glow plug from the power supply means so that the temperature of the glow plug is set to be lower than a requested temperature in compliance with the request of passing the current through the glow plug when the remaining life of the plug is at or below a stipulated value. This constitution can extend the life of the glow plug more when a combustion condition is deteriorated in a combustion chamber in a highland travel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glow plug energization amount control device for an internal combustion engine that controls an energization amount from a power supply means to a glow plug.

  Conventionally, a diesel engine as an example of an internal combustion engine is generally provided with a glow plug for preheating the combustion chamber in order to improve the startability of the engine. Inside the tip of the glow plug, a heating wire is provided for heating by energizing the glow plug, and the tip of the glow plug is provided so as to be exposed in the combustion chamber. For this reason, by energizing the glow plug for a predetermined period, the heating wire generates heat and the combustion chamber is heated. Thereby, the ignitability with respect to the fuel-air mixture in the combustion chamber can be improved, and the engine startability can be improved.

  For example, Patent Documents 1 to 3 describe a diesel engine having such a glow plug.

  In the diesel engine combustion apparatus described in Patent Document 1, the combustion temperature is automatically raised by energizing the glow plug during light load high speed operation.

  In the fuel injection timing control device for a diesel engine described in Patent Document 2, even after the engine is started, the glow plug is continuously energized until the engine cooling water temperature reaches a predetermined reference value, so that the inside of the combustion chamber is The temperature rise is promoted. Further, in this fuel injection timing control device for a diesel engine, the fuel injection timing is corrected based on the temperature of the glow plug and the coolant temperature.

  In the control device for a diesel engine described in Patent Document 3, in order to suppress the generation of deposits, the glow recirculation device is operated when the exhaust gas recirculation device is operating after the engine warm-up is completed and the temperature of the combustion gas is low. The plug is activated.

  Patent Document 4 discloses a spark plug monitoring device that can monitor deterioration and short-circuit of a spark plug of a gas engine and estimate the remaining life of an additive plug.

JP 9-42137 A JP 62-32252 A JP 2005-113875 A JP-A-10-189213

  As described above, the glow plug is generally used to improve engine startability. However, it is also effective to use the glow plug as a means for promoting combustion when the combustion state tends to deteriorate in the combustion chamber, such as when the engine is started at a high altitude other than when the engine is started.

  That is, at a high altitude with a high altitude, the temperature of the air (intake air) sucked into the combustion chamber decreases as the atmospheric pressure decreases, so the temperature in the combustion chamber decreases. For this reason, the ignitability with respect to the air-fuel mixture is reduced in the combustion chamber, and the combustion state is deteriorated. As a result, white smoke is discharged to the outside or misfire occurs. Therefore, when the combustion state deteriorates in the combustion chamber, it is desirable to always operate the glow plug to increase the ignition energy for the air-fuel mixture in the combustion chamber.

  However, if the glow plug is always operated without interruption, there is a problem that the life of the glow plug becomes extremely short.

  The present invention has been made in view of the above points. When the combustion state deteriorates in the combustion chamber, the life of the glow plug is extended by appropriately controlling the amount of current supplied to the glow plug. An object of the present invention is to provide a glow plug energization control device for an internal combustion engine.

  In one aspect of the present invention, a glow plug energization amount control device for an internal combustion engine includes a glow plug that promotes heating of a combustion chamber, power supply means that supplies power to the glow plug, and By controlling the energization amount to the glow plug, a glow plug energization amount control means for controlling the temperature of the glow plug, a storage means for storing the energization history pattern of the glow plug, and an energization request to the glow plug are provided. And a glow plug remaining life calculating means for calculating a remaining life of the glow plug based on the energization history pattern. When the remaining life is less than a specified value, the temperature of the glow plug is set lower than the required temperature according to the energization request of the glow plug. Sea urchin, adjusting the amount of current to the glow plug from the power supply unit.

  The glow plug energization amount control device for an internal combustion engine includes a glow plug that promotes heating of the combustion chamber, power supply means such as a battery that supplies power to the glow plug, and energization from the power supply means to the glow plug. Glow plug energization amount control means for controlling the temperature of the glow plug as a heating element by controlling the amount (including energization time and electric energy), storage means for storing the energization history pattern of the glow plug, and the glow plug And a glow plug remaining life calculating means for calculating the remaining life (remaining life) of the glow plug based on the current supply history pattern when there is an energization request.

  In particular, the glow plug energization amount control means sets the glow plug temperature to be lower than a required temperature corresponding to the glow plug energization request when the calculated remaining life of the glow plug is not more than a specified value. Then, the energization amount from the power supply means to the glow plug is adjusted. Here, the reason why the temperature of the glow plug is set low is that the remaining life of the glow plug can be made longer than the general relationship between the temperature of the glow plug and the life of the glow plug. In a preferred example, the temperature of the glow plug relative to the required temperature is preferably lowered according to the remaining life of the glow plug. As a result, when the combustion state deteriorates in the combustion chamber, such as when starting an internal combustion engine or running at a high altitude, compared to using a glow plug without considering the remaining life of the glow plug. It is possible to further extend the life of the glow plug.

  Here, although the method of selecting the specified value is arbitrary, considering the prevention of deterioration of the combustion state in the combustion chamber and the extension of the remaining life of the glow plug, the specified value remains the remaining life of the glow plug. It is preferable that the value be small.

  In one aspect of the glow plug energization amount control device for the internal combustion engine, the glow plug energization request determination means for determining whether or not there is an energization request for the glow plug, and the temperature of the cooling water for cooling the internal combustion engine are detected. A cooling water temperature detection means, and the glow plug energization request determination means is based on the detected temperature of the cooling water and the energization time for the glow plug according to the temperature of the cooling water. It is preferable to determine whether or not there is an energization request to the glow plug.

  In another aspect of the glow plug energization amount control device for an internal combustion engine, the apparatus further comprises combustion control means for controlling a value of a combustion parameter that affects a combustion state in the combustion chamber, wherein the combustion control means comprises the glow plug When the temperature of the combustion chamber is set lower than the required temperature according to the energization request of the glow plug, the temperature of the combustion chamber is increased by the difference between the required temperature and the temperature of the glow plug set low. The value of the combustion parameter is adjusted.

  In this aspect, it further includes combustion control means for controlling the value of the combustion parameter that affects the combustion state in the combustion chamber. When the temperature of the glow plug is set lower than the required temperature corresponding to the energization request of the glow plug, the combustion control means burns by the difference between the required temperature and the temperature of the glow plug set low. Since the chamber temperature decreases, the value of the combustion parameter is adjusted so that the temperature in the combustion chamber increases accordingly.

  Here, examples of the combustion parameter include an exhaust gas recirculation amount (EGR gas amount), a fuel injection timing, a fuel injection pressure of a common rail, and the like. Therefore, if the combustion control means is an internal combustion engine equipped with an exhaust gas recirculation device (EGR device), the combustion control means controls the exhaust gas recirculation amount to be reduced, advances the fuel injection timing, and controls the common rail. If the internal combustion engine is equipped with a fuel injection system, the value of the combustion parameter is controlled by a method such as controlling the fuel injection pressure of the common rail to be large. The combustion control means desirably executes at least one of the plurality of control methods, or executes a combination of the plurality of controls. This makes it possible to prevent the deterioration of the combustion state while extending the life of the glow plug when the combustion state is likely to deteriorate in the combustion chamber, such as when starting the internal combustion engine or traveling at a high altitude at a high altitude. .

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[overall structure]
First, a configuration of an internal combustion engine to which a glow plug energization amount control device for an internal combustion engine according to an embodiment of the present invention is applied will be described with reference to FIG.

  FIG. 1 schematically shows a configuration diagram of an internal combustion engine to which a glow plug energization amount control device for an internal combustion engine according to the present embodiment is applied. In FIG. 1, solid arrows indicate gas flows, and broken arrows indicate input / output of signals.

  An internal combustion engine (engine) 100 is controlled by an ECU (Engine Control Unit) 50 and mainly includes a cylinder 1 and a cylinder head 2. The internal combustion engine 100 is configured as a diesel engine, for example.

  The cylinder (cylinder) 1 is disposed below the cylinder head 2. A water jacket 3 through which cooling water for cooling each part of the internal combustion engine 100 flows is provided inside the cylinder 1 and the like. The temperature of the cooling water flowing through the water jacket 3 is detected by a water temperature sensor (cooling water temperature detecting means) 5 attached to the cylinder 1. Inside the cylinder 1, the piston 4 is arranged so as to be capable of reciprocating along the cylinder 1. A combustion chamber 6 is formed between the piston 4, the cylinder 1 and the cylinder head 2.

  The cylinder head 2 is mainly provided with an intake passage 7, an intake valve 8, an exhaust passage 9, an exhaust valve 10, a fuel injection valve 11, and a glow plug 12. Air (intake air) introduced from the outside passes through the intake passage 7, and the passed air is supplied to the combustion chamber 6. The intake valve 8 is controlled to be opened and closed by the ECU 50, thereby communicating / blocking the intake passage 7 and the combustion chamber 6. The fuel injected by the fuel injection valve 11 is supplied to the combustion chamber 6. The fuel injection valve 11 is controlled by the ECU 50 such as the fuel injection amount and the fuel injection timing.

  The glow plug 12 heats the inside of the combustion chamber 6 to promote combustion of the air-fuel mixture when the combustion state deteriorates in the combustion chamber 6 such as when the internal combustion engine 100 is started or travels at a high altitude at a high altitude. Used for. A heating wire (not shown) is provided inside the tip portion 12 a of the glow plug 12, and the tip portion 12 a is disposed so as to be exposed in the combustion chamber 6. The glow plug 12 is electrically connected to the power supply means 14 via the glow plug energization amount control means 13. The power supply means 14 is a battery, for example, and supplies power to the glow plug 12. The glow plug energization amount control means 13 includes an amplification circuit (not shown) that amplifies the power supplied from the power supply means 14, and the glow plug 12 from the power supply means 14 based on a control signal s1 supplied from the ECU 50. The temperature of the front end portion 12a of the glow plug 12 that generates heat is controlled by controlling the amount of current supplied to the heater (including the current supply time and the amount of power; the same applies hereinafter). Note that the temperature of the tip 12a of the glow plug 12 is estimated based on at least one parameter among, for example, atmospheric pressure, the temperature of intake air that passes through the intake passage 7, and the temperature of cooling water. However, in the present invention, as a method for measuring the temperature of the tip 12a of the glow plug 12, a known method may be adopted.

  For example, the glow plug energization amount control means 13 increases the temperature of the tip 12a of the glow plug 12 by increasing the energization amount to the glow plug 12 based on the control signal s1 supplied from the ECU 50, while the glow plug energization amount control means 13 The temperature of the tip end portion 12a of the glow plug 12 is lowered by reducing the amount of current supplied to the plug 12. By such control, the heating wire provided in the tip portion 12a of the glow plug 12 generates heat to heat the inside of the combustion chamber 6, and the combustion of the air-fuel mixture in the combustion chamber 6 is promoted.

  By such combustion of the air-fuel mixture in the combustion chamber 6, the piston 4 reciprocates along the cylinder 1, and this reciprocating motion is transmitted to the crankshaft (not shown) via the connecting rod 4a to rotate the crankshaft. . Further, the exhaust gas generated by the combustion of the air-fuel mixture in the combustion chamber 6 is discharged to the exhaust passage 9. The exhaust valve 10 is controlled to be opened and closed by the ECU 50, thereby communicating / blocking the exhaust passage 9 and the combustion chamber 6.

  The ECU 50 includes a CPU (Central Processing Unit) (not shown) and storage means (not shown) such as a ROM (Read Only Memory) and a RAM (Random Access Memory) (not shown). The ECU 50 acquires detection signals from various sensors provided in the internal combustion engine 100, and controls the internal combustion engine 100 based on the detection signals. The various sensors include the water temperature sensor (cooling water temperature detecting means) 5 described above, and the temperature of the cooling water detected by the water temperature sensor 5 is output to the ECU 50 as an output signal s2. In particular, in the present invention, the ECU 50 has a glow plug energization request determination means for determining whether or not there is an energization request to the glow plug 12 based on the operating state of the internal combustion engine 100, and when there is an energization request to the glow plug 12. The glow plug remaining life calculating means for calculating the remaining life (remaining life) of the glow plug 12 based on the energization history pattern of the glow plug 12 stored in the storage means, which affects the combustion state in the combustion chamber 6. It functions as a combustion control means for controlling the value of the given combustion parameter.

[Energization amount control device for internal combustion engine]
As described above, in addition to the time when the internal combustion engine 100 is started, when the combustion state is deteriorated in the combustion chamber 6 such as traveling in a high altitude at a high altitude, from the viewpoint of white smoke emission prevention and misfire prevention, It is desirable to always operate the glow plug 12 to promote the temperature rise in the combustion chamber 6 and improve the ignitability of the air-fuel mixture in the combustion chamber 6. However, if the glow plug 12 is always operated without interruption, there is a problem that the life of the glow plug 12 is extremely shortened.

  Therefore, in order to improve such a problem, the glow plug energization amount control device for the internal combustion engine according to the embodiment of the present invention supplies the glow plug 12 that promotes heating in the combustion chamber 6 and the glow plug 12 with electric power. Glow plug energization for controlling the temperature of the glow plug 12 as a heating element by controlling the energization amount from the power supply means 14 to the glow plug 12 based on the power supply means 14 and the control signal s1 supplied from the ECU 50. Based on the energization history pattern of the glow plug 12 stored in the storage means when there is an energization request to the amount control means 13, the energization history pattern of the glow plug 12, and the glow plug 12. Glow plug remaining life calculating means for calculating the remaining life of the glow plug 12, and the glow plug energization amount control means When the remaining life of the glow plug 12 calculated by the lug remaining life calculating means is equal to or less than a specified value, the energization amount from the power supply means 14 to the glow plug 12 is adjusted, and a request according to the energization request of the glow plug 12 It is characterized by being set lower than the temperature. Hereinafter, a glow plug energization amount control method by the glow plug energization amount control device of the internal combustion engine will be described.

(Glow plug energization control process for internal combustion engine)
First, the glow plug energization amount control process for the internal combustion engine according to the present embodiment will be described with reference to FIGS.

  FIG. 2 shows a flowchart according to the glow plug energization amount control process of the internal combustion engine of the present embodiment. FIG. 3 shows an example of a cooling water temperature-glow plug energization time map used for calculating the energization time for the glow plug 12 from the temperature of the cooling water for cooling each part of the internal combustion engine 100.

  First, the ECU 50 determines whether or not there is an energization request to the glow plug 12 (step S1). Here, the presence / absence of the energization request to the glow plug 12 is determined by the glow plug energization request determination means of the ECU 50. The glow plug energization request determination means determines that the energization request to the glow plug 12 is “present” when it is necessary to improve the ignitability of the air-fuel mixture in the combustion chamber 6 based on the operating state of the internal combustion engine 100. If not, the energization request to the glow plug 12 is determined as “none”. For example, the glow plug energization request determining unit refers to the cooling water temperature-glow plug energization time map illustrated in FIG. 3 and determines whether or not there is an energization request to the glow plug 12 based on the temperature of the cooling water. In this map, the energization time to the glow plug 12 decreases as the temperature of the cooling water increases. In these cases, since it is necessary to improve the ignitability of the air-fuel mixture in the combustion chamber 6, the glow plug energization request determination means determines that the energization request to the glow plug 12 is “present”. On the other hand, when the temperature of the cooling water is sufficiently high and the combustion state is good in the combustion chamber 6, the energization time to the glow plug 12 is 0. In this case, the glow plug energization request determining means The energization request to the plug 12 is determined as “none”.

  When the glow plug energization request determination unit determines that the energization request to the glow plug 12 is “none” (step S1; No), the ECU 50 stops energization from the power supply unit 14 to the glow plug 12. (Step S8). Thereby, the heating into the combustion chamber 6 by the glow plug 12 is stopped. On the other hand, when it is determined that the energization request to the glow plug 12 is “present” (step S1; Yes), the ECU 50 reads the energization history pattern of the glow plug 12 stored in the storage unit (step S2). Based on the energization history pattern of the glow plug 12, the remaining life hr of the glow plug 12 is calculated (step S3).

  Here, an example of a method for calculating the remaining life hr of the glow plug 12 based on the energization history pattern of the glow plug 12 will be described with reference to FIG.

  FIG. 4A shows the relationship between the temperature [° C.] of the tip 12 a of the glow plug 12 and the lifetime [time] of the glow plug 12 when the glow plug 12 is always operated. An example of a plug life map is shown. From the map of FIG. 4A, it can be seen that the lifetime of the glow plug 12 increases as the temperature of the tip 12a of the glow plug 12 decreases. FIG. 4B is a chart showing an example of the energization history pattern of the glow plug 12 based on the map of FIG.

Here, the remaining life hr [year] of the glow plug 12 is the following formula 1 in the case of the energization history pattern of the glow plug 12 illustrated in FIG.
hr [year] = 1 / {(α / h2) + (β / h1)} (Formula 1)
Is calculated by

  Here, in the right term of the above-mentioned formula 1, “α” indicates the energization time for one year of the glow plug 12 when the temperature of the tip 12a of the glow plug 12 is t2. “H2” indicates the life [hour] of the glow plug 12 when the glow plug 12 is always operated under the condition that the temperature of the tip 12a of the glow plug 12 is t2. “Β” indicates a one-year energization time of the glow plug 12 when the temperature of the tip 12a of the glow plug 12 is t1 (<t2). “H1” indicates the life [hour] of the glow plug 12 when the glow plug 12 is always operated under the condition that the temperature of the tip 12a of the glow plug 12 is t1 (<t2). In Equation 1 above, since the remaining life hr [year] of the glow plug 12 is calculated based on the energization history pattern of the glow plug 12 shown in FIG. 4B, the number of denominator terms is 2. However, depending on the energization history pattern of the glow plug 12, the number of terms in the denominator is increased or decreased in Equation 1 above. Further, the calculation method of the remaining life hr according to the above formula 1 is merely an example, and in the present invention, various known methods may be used as the calculation method of the remaining life hr.

  Returning to FIG. 2, next, the ECU 50 determines whether or not the remaining life hr calculated by the glow plug remaining life calculating means is equal to or less than a specified value hf (step S4). Here, although the way of selecting the specified value hf is arbitrary, in consideration of preventing deterioration of the combustion state in the combustion chamber 6 and extending the remaining life of the glow plug 12, the specified value hf is set to the glow plug 12. It is preferable to set the value so that the remaining lifetime is a little. For example, it is assumed that the life of the glow plug 12 is 16000 hours when the glow plug 12 is always operated under the condition that the temperature of the tip 12a of the glow plug 12 is 800 ° C. In this case, the specified value hf can be a value at which the remaining life of the glow plug 12 becomes a little, for example, 2000 hours that is (1/8) times the 16000 hours that is the life of the glow plug 12.

  In step S4, when the remaining life hr of the glow plug 12 is greater than the specified value hf (step S4; No), the remaining life of the glow plug 12 is not short, so the ECU 50 determines the temperature of the tip 12a of the glow plug 12. Is set to a required temperature corresponding to the energization request to the glow plug 12 in step S1 (step S6), and further, the glow plug energization amount control is performed so that the temperature of the tip portion 12a of the glow plug 12 becomes the required temperature. The energization amount from the power supply means 14 to the glow plug 12 is adjusted through the means 13 (step S7).

  On the other hand, if the remaining life hr of the glow plug 12 is equal to or less than the specified value hf in step 4 (step S4; Yes), the remaining life of the glow plug 12 becomes very small. Priority is given to extending the remaining life of the glow plug 12 over the prevention of deterioration of the combustion state in the combustion chamber 6 such as traveling at a high altitude, and the temperature of the tip 12a of the glow plug 12 is determined by the glow plug in step S1. 12 is set to be lower than the required temperature corresponding to the energization request to 12 (step S5). That is, here, the reason why the temperature of the tip 12a of the glow plug 12 is set low is that the remaining life hr of the glow plug 12 can be lengthened from the map of FIG. is there. Note that the temperature of the glow plug 12 with respect to the required temperature is preferably lowered according to the remaining life hr of the glow plug 12. In this case, for example, according to the remaining life hr of the glow plug 12, the set temperature of the tip 12a of the glow plug 12 is lowered in a stepped manner, or as the remaining life hr of the glow plug 12 becomes shorter, the tip of the glow plug 12 A method such as lowering the set temperature of the portion 12a linearly or non-linearly can be employed.

  Next, the ECU 50 adjusts the energization amount from the power supply means 14 to the glow plug 12 through the glow plug energization amount control means 13 so that the temperature of the tip 12a of the glow plug 12 is lower than the required temperature. (Step S7). Thereby, when the combustion state deteriorates in the combustion chamber 6, the lifetime hr of the glow plug 12 is further increased compared to the case where the glow plug 12 is used without considering the remaining lifetime hr of the glow plug 12. It can be extended.

(Glow plug energization amount control method for internal combustion engine according to application example)
In the above embodiment, in order to extend the remaining life hr of the glow plug 12 as much as possible, when the remaining life hr of the glow plug 12 is equal to or less than the specified value hf, the temperature of the tip 12a of the glow plug 12 is set to the above requirement. It was set to be lower than the temperature. However, if the temperature of the tip portion 12a of the glow plug 12 is set low, the temperature in the combustion chamber 6 is lowered accordingly, and the combustion state in the combustion chamber 6 is deteriorated.

  Therefore, in the glow plug energization amount control method for the internal combustion engine according to the application example of the present invention, the internal combustion engine 100 sets the value of the combustion parameter that affects the combustion state in the combustion chamber 6 in order to cope with such a problem. Combustion control means for controlling, the combustion control means, when the temperature of the tip 12a of the glow plug 12 is set lower than the required temperature according to the energization request to the glow plug 12 as described above It is desirable to adjust the value of the combustion parameter so that the temperature in the combustion chamber 6 is increased by the difference between the required temperature and the temperature of the glow plug 12 set to be low.

  Hereinafter, a glow plug energization amount control method for an internal combustion engine according to an application example of the present invention will be described with reference to FIG. FIG. 5 shows a flowchart of a glow plug energization amount control method for an internal combustion engine according to an application example of the present invention.

  When the glow plug energization amount control process for the internal combustion engine according to the above-described embodiment is compared with the glow plug energization amount control process for the internal combustion engine according to the application example of the present invention, the glow plug of the internal combustion engine according to the application example of the present invention is compared. The energization amount control process is different from the glow plug energization amount control process of the internal combustion engine according to the above-described embodiment only in that steps S9 and S10 are added.

  That is, in the glow plug energization amount control process of the internal combustion engine according to the application example of the present invention, it is determined whether or not the temperature of the tip end portion 12a of the glow plug 12 is set lower than the required temperature in step S5 after executing step S7. (Step S9). If the temperature of the tip 12a of the glow plug 12 is set lower than the required temperature (step S9; Yes), the difference between the required temperature and the temperature of the glow plug 12 set lower will be within the combustion chamber 6. Therefore, the combustion parameter value is controlled to promote combustion of the air-fuel mixture in the combustion chamber 6 (step S10). Here, examples of the combustion parameter include an exhaust gas recirculation amount (EGR gas amount), a fuel injection timing, a fuel injection pressure of a common rail, and the like. Therefore, in step S10, if the combustion control means is an internal combustion engine equipped with an exhaust gas recirculation device (EGR device), control is performed so that the exhaust gas recirculation amount is reduced, and the fuel injection timing is advanced. In the case of an internal combustion engine equipped with a common rail fuel injection system, the value of the combustion parameter is controlled by a method such as controlling the fuel injection pressure of the common rail to increase. In step S10, it is desirable that the combustion control means execute at least one control method among the plurality of control methods, or execute a combination of the plurality of controls. As a result, when the combustion state is likely to deteriorate in the combustion chamber 6 such as when the internal combustion engine 100 is started or traveling at a high altitude, the life of the glow plug 12 can be extended and the deterioration of the combustion state can be prevented. can do.

  On the other hand, if the temperature of the tip 12a of the glow plug 12 is not set lower than the required temperature (step S9; No), that is, the temperature of the tip 12a of the glow plug 12 is set to the required temperature in step S6. If so, the combustion state in the combustion chamber 6 has not deteriorated, so the value of the combustion parameter is not controlled.

1 is a configuration diagram of an internal combustion engine to which a glow plug energization amount control device for an internal combustion engine according to the present embodiment is applied. FIG. 6 shows a flowchart according to glow plug energization amount control processing of the internal combustion engine of the present embodiment. An example of the cooling water temperature-glow plug energization time map which concerns on this embodiment is shown. An example of the glow plug tip temperature-glow plug lifetime map which concerns on this embodiment, and an example of the chart which concerns on the energization history pattern of a glow plug are shown. 7 shows a flowchart relating to glow plug energization amount control processing of an internal combustion engine according to an application example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Water temperature sensor 6 Combustion chamber 12 Glow plug 12a Tip part 13 Glow plug energization amount control means 14 Electric power supply means 50 ECU
100 Internal combustion engine

Claims (3)

A glow plug that promotes heating of the combustion chamber;
Power supply means for supplying power to the glow plug;
Glow plug energization amount control means for controlling the temperature of the glow plug by controlling the energization amount from the power supply means to the glow plug;
Storage means for storing an energization history pattern of the glow plug;
A glow plug remaining life calculating means for calculating a remaining life of the glow plug based on the current supply history pattern when there is an energization request to the glow plug;
The glow plug energization amount control means may set the temperature of the glow plug to be lower than a required temperature according to the energization request of the glow plug when the calculated remaining life of the glow plug is not more than a specified value. Further, the glow plug energization amount control device for an internal combustion engine, wherein the energization amount from the power supply means to the glow plug is adjusted. Glow plug energization request determination means for determining whether or not there is an energization request to the glow plug;
Cooling water temperature detecting means for detecting the temperature of the cooling water for cooling the internal combustion engine,
The glow plug energization request determination means determines whether there is an energization request for the glow plug based on the detected temperature of the cooling water and an energization time for the glow plug according to the temperature of the cooling water. The glow plug energization amount control device for an internal combustion engine according to claim 1, wherein: Combustion control means for controlling the value of a combustion parameter that affects the combustion state in the combustion chamber;
The combustion control means, when the temperature of the glow plug is set lower than the required temperature according to the energization request of the glow plug, the difference between the required temperature and the temperature of the glow plug set low. The glow plug energization amount control device for an internal combustion engine according to claim 1 or 2, wherein the value of the combustion parameter is adjusted so that the temperature of the combustion chamber becomes high.

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