JP2010175116A - Device and method for controlling current carrying of glow plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize operation at low intake air temperature while saving electric power. <P>SOLUTION: In this method of controlling current carrying of a glow plug 4, after start of a diesel engine, electric power supply to the glow plug 4 is controlled, and after-glow is performed so that the temperature of the glow plug becomes a predetermined set target temperature. Using the temperature resistant characteristics of the glow plug 4, the temperature of the glow plug 4 is detected, and the temperature change in the glow plug 4 is detected along with air intake during cranking, so as to detect the intake air temperature. When the intake air temperature Tin is low, the target temperature of after-glow is set high. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a glow plug energization control device and a control method therefor.

  In recent years, with regard to diesel engine glow plugs, not only preheating before starting the engine (sometimes referred to as “preheating glow” in this document), but also after the engine is started, the glow plug is energized to a relatively high temperature. In order to reduce engine vibration and noise and to clean exhaust gas, the afterglow is maintained.

On the other hand, when this afterglow is executed, power consumption increases. For this reason, in order to suppress power consumption as much as possible, for example, the technique described in Patent Document 1 detects a cooling water temperature of the engine, and a control method that shortens the energization time (afterglow time) to the glow plug as the temperature increases. Proposed.
JP-A 63-5173

  However, even if the cooling water temperature of the engine becomes high to some extent, the surface of the glow plug is cooled by the swirl because the intake air temperature is low in an extremely low temperature such as -40 ° C in an extremely cold area in winter. It may be done. Then, in the glow plug energization control device described above, the energization time to the glow plug is shortened when the cooling water temperature is high, so that the glow plug becomes low temperature and the after glow does not work properly, and eventually idling is not stable. was there.

  The present invention has been completed based on the above circumstances, and the temperature of the glow plug that can stabilize the operation of the engine even when the intake air temperature to the engine is low while achieving power saving of the afterglow. An object is to provide a control device.

  According to the glow plug energization control method of the present invention, after the diesel engine is started, the glow plug is controlled to control the electric power supplied to the glow plug so that the glow plug temperature reaches a predetermined target temperature that is set. The energization control method is characterized in that the target temperature is set high when the intake air temperature to the diesel engine is low.

  According to the present invention, when the intake air temperature to the engine is low, the target temperature of the glow plug temperature is set high. Therefore, even if heat is taken away from the glow plug by swirl, the temperature inside the engine can be maintained high, and the engine Contributes to the stable operation of

  Here, the intake air temperature of the diesel engine can be calculated based on the preheat temperature of the glow plug before the start of the diesel engine and the temperature after the start of the glow plug changed by the intake operation accompanying the start of the diesel engine.

  A glow plug energization control device according to the present invention is a glow plug energization control device for performing after glow by supplying electric power to a glow plug after starting a diesel engine, and a glow plug temperature detecting means for detecting the temperature of the glow plug. A power control means for controlling the power supplied to the glow plug so that the temperature detected by the glow plug temperature detection means is set to a predetermined target temperature provided in the energization path to the glow plug, and to the diesel engine An intake air temperature detecting means for detecting the intake air temperature of the engine and a target for setting the target temperature in the power control means to be lower as the intake air temperature is higher based on the signal from the intake air temperature detecting means, and to set the target temperature higher as the intake air temperature is lower It is characterized in that it includes a temperature setting means.

  In the glow plug energization control device, the glow plug temperature detecting means includes a resistance measuring means for measuring a resistance when the glow plug is energized, and the glow plug is based on a temperature-resistance characteristic of a resistance heating element included in the glow plug. The temperature can be detected.

  With this configuration, since the temperature of the glow plug can be measured using the resistance heating element of the glow plug itself, it is not necessary to separately provide a dedicated temperature sensor for measuring the temperature of the glow plug.

  Further, the intake air temperature detecting means includes a glow plug preheating temperature before starting the diesel engine measured by the glow plug temperature detecting means, and a temperature after the start of the glow plug changed by an intake operation accompanying the start of the diesel engine. The intake air temperature can be detected based on the intake air temperature.

  Even after the glow plug is preheated to a predetermined temperature and the diesel engine is started, the lower the intake air temperature, the more heat is taken away from the glow plug by the influence of the swirl in the cylinder, and the temperature drops further. . This means that the intake air temperature can be estimated by observing the temperature change of the glow plug after starting the engine. Therefore, in the above configuration, the intake air temperature is detected based on the temperature after the start of the glow plug, which has changed due to the intake operation after the engine is started. In general, the intake air temperature can be detected by providing an intake air temperature sensor in the intake path to the engine. However, with the above configuration, the intake air temperature sensor is not provided and the intake air can be detected using the glow plug itself. Since the temperature can be detected, the configuration is simplified.

  Further, the intake air temperature detecting means includes a post-starting temperature difference calculating means for obtaining a temperature difference between the preheating temperature and a post-starting temperature when a predetermined time has elapsed after starting the diesel engine, and a plurality of intake air temperatures obtained in advance. And a storage means for storing the relationship between the temperature difference and the temperature difference, and a reading means for reading out the intake air temperature from the table stored in the storage means in accordance with the temperature difference calculated by the post-starting temperature difference calculation means. be able to.

  This simplifies the arithmetic processing and enables high-speed processing.

  According to the present invention, it is possible to achieve both power saving of the afterglow and stabilization of engine operation.

An embodiment of the present invention will be described with reference to the drawings.
1. Overall Configuration In this embodiment, a glow plug energization control device 1 applied to, for example, a four-cylinder diesel engine (hereinafter referred to as “engine”) will be described as an example.

  As shown in FIG. 1, a glow plug energization control device 1 is connected to an engine fuel injection electronic control unit (EFI-ECU) 2, a battery 3 mounted on the vehicle and serving as a DC power source, and four glow plugs 4. ing. Although not shown, the glow plug 4 has a known structure in which a resistance heating element is accommodated in a metal outer cylinder, and is installed in each cylinder of the engine.

  The EFI-ECU 2 is a control computer that controls each part of the engine. The EFI-ECU 2 outputs an energization command to the glow plug energization control device 1 when the ignition switch IG is turned on and the engine is started. Various sensors for grasping the operating state of the engine are connected to the EFI-ECU 2.

  The glow plug energization control device 1 includes a control unit 20 including a CPU 21, a switching unit 30 including an FET 31, and a reverse connection protection circuit 40.

  The control unit 20 functions as “glow plug temperature detecting means”, “power control means”, “intake air temperature detecting means”, and “target temperature setting means” in the present invention, as will be apparent from the description of the operation described later. In addition, a ROM 22 and a RAM 23 for storing various programs and data are provided.

  The switching unit 30 constitutes a part of the “power control means” in the present invention. The switching unit 30 includes a FET 31 formed of a power MOSFET or the like, a voltage measuring circuit for detecting the source voltage of the FET 31, and a sense FET. It is equipped with a current detection circuit that detects the source current of the FET 31, which is an FET, and is composed of a so-called IPS (Intelligent Power Device) that has a protection function for overheating, overcurrent, overvoltage, etc. and a load short-circuiting / opening diagnosis function. .

  The reverse connection protection circuit 40 is connected to the + B terminal of the battery 3 on the power supply side. On the load side of the reverse connection protection circuit 40, the circuit branches into four branches, which are connected to the glow plug 4 via the switching unit 30. The reverse connection protection circuit 40 includes a P-channel MOSFET 41, the gate of which is grounded via a resistor 42, Zener diodes 43 and 44 connected in opposite directions to each other between the gate and source, and a body diode between the drain and source. 45 is connected in parallel in the forward direction. As a result, in the unlikely event that the battery 3 is connected in the reverse polarity, the MOSFET 41 and the body diode 45 are kept off, so that current does not flow through the glow plug 4.

2. Control Mode [1] Glow Plug Temperature Measurement Principle Generally, the relationship between the temperature T [° C.] of the resistance heating element of the glow plug 4 and its resistance value R [Ω], that is, the temperature-resistance characteristic is the resistance of the glow plug. If the resistance temperature coefficient of the heating element is k (which is a specific value depending on the material), and the resistance value at 0 ° C. is R 0, it can be approximated by the following linear expression.

R = R0 (1 + kT) (1)
Accordingly, when the target temperature is Tp, the resistance value (target resistance value Rp) at that time is a value represented by the following equation (2). Therefore, energization is performed so that the resistance value of the glow plug becomes the target resistance value Rp. If controlled, the temperature of the resistance heating element of the glow plug at that time becomes the target temperature Tp.

Rp = R0 (1 + kTp) (2)
Note that the glow plug 4 has manufacturing errors in the cross-sectional area and length of the resistance heating element, and therefore the resistance value varies between the glow plugs 4 even at the same temperature. For this reason, even if the same resistance value is reached, the temperature of each glow plug 4 is not necessarily the same. Therefore, if the same target resistance value Rp is set for all the glow plugs 4, even if the resistance value of the glow plug 4 reaches the target resistance value Rp, the temperature may be different from the target temperature Tp. There is sex.

  Therefore, in this embodiment, for each glow plug 4, the resistance value at which the temperature becomes the target temperature Tp is set as the target resistance value Rp specific to the glow plug, and when the respective target resistance value Rp is reached. In addition, the glow plugs 4 are individually disconnected. Thereby, it is possible to control the temperature of all the glow plugs 4 to the same target temperature Tp.

  In the above equation (1), R0 (resistance value at 0 ° C.) varies depending on the manufacturing error as described above, and varies depending on the glow plug 4. Therefore, the relationship between the resistance value of the glow plug 4 and the temperature based on the equation (1). Is required for each glow plug 4. For this purpose, for each glow plug 4, R0 is obtained by measuring a resistance value Rini at a specific temperature (initial temperature Tini) and substituting T = Tini and R = Rini into the equation (1). it can.

  In this case, in the present embodiment, since the glow plug 4 is not provided with a temperature sensor for measuring the temperature, the initial temperature Tini of the glow plug 4 cannot be directly measured. However, when the engine has been stopped for a long period of time, the temperature of all the glow plugs 4 is substantially equal to the temperature of the cooling water, the cylinder block, etc. before the glow plugs 4 are energized. Can be considered.

  Therefore, in the present embodiment, the engine is started after being stopped for a long period of time, and before the preheating energization to the glow plug 4, the glow sensor 4 is controlled based on a signal from a temperature sensor that measures the coolant temperature. The initial temperature Tini (cooling water temperature) of the plug 4 is read, the resistance value Rini at that time is measured, and R0 is calculated based on these values. If R0 is known, the resistance temperature coefficient k of the resistance heating element of the glow plug 4 is known, and the temperature can be known from the resistance of the glow plug 4 by using the equation (1). This eliminates the need for a separate temperature sensor for measuring the temperature of the glow plug 4.

[2] Initialization of Variables in Glow Plug Temperature Detection Unit Based on the above principle, in this embodiment, the glow plug temperature detection unit performs a preparatory operation for detecting the temperature of each glow plug 4 as follows. .
The glow plug temperature detecting means of this embodiment includes resistance measuring means for measuring the resistance when the glow plug is energized. The resistance measuring means receives a voltage measurement circuit for measuring the source voltage of the FET 31 in the switching unit 30, a current measurement circuit for measuring the source current of the FET 31 constituted by the sense FET, and signals from these circuits, The CPU 21 calculates a value (resistance value) obtained by dividing the voltage value when the plug 4 is energized by the current value.

  When the control unit 20 of the glow plug energization control device 1 receives a preheating command for starting the engine from the EFI-ECU 2, the control unit 20 starts the preheating control shown in FIG. When the engine has been stopped for a long time that can be considered to be substantially equal to the temperature of, the control unit 20 performs an initialization operation of variables as shown in FIG. 3 (step S101). If the time since the engine is stopped is short and the cooling water temperature and the glow plug temperature do not match, this initialization operation is omitted and the previous value is used.

First, the control unit 20 energizes the single glow plug 4 for a short time (step S111). This is performed by turning on the FET 31 of the switching unit 30 for a short time, such as 2 milliseconds, while the remaining three glow plugs 4 are disconnected. At that time, the source current and the source voltage of the FET 31 are measured by the current measurement circuit and the voltage measurement circuit of the switching unit 30, respectively, and the initial resistance value Rini is calculated based on the measurement (step S112). On the other hand, the coolant temperature at that time is acquired from the EFI-ECU 2, and this is regarded as the initial temperature Tini of the glow plug 4 (step S113). Based on these, the resistance value R0 of the heating resistor of the glow plug 4 is calculated by R = Rint and T = Tini in the above equation (1), and the specific value is substituted into R0 in the equation (1). Then, initialization is performed (step S114).
These processes are repeated until all resistance values R0 are obtained for all four glow plugs 4, but in this embodiment, the initial temperature Tini uses the same value.

[3] Energization control in preheating glow When the variable initialization operation is completed, the target temperature Tta and the resistance temperature coefficient k of each glow plug 4 corresponding to the target temperature during preheating glow stored in advance in the RAM 23 are read out. Based on this and the resistance value R0 set as described above, the target resistance value Rp of each glow plug 4 corresponding to the target temperature Tta is calculated and stored in the RAM 23 (step S103). In this embodiment, the target temperature Tta of each glow plug 4 is the same temperature for each cylinder, but this may be varied for each cylinder.

  Next, the control unit 20 turns on the FETs 31 of all the switching units 30 to energize each glow plug 4 to generate heat (step S104). At the same time, the control unit 20 detects the current flowing through the glow plug 4 (source current of the FET 31) by the current detection circuit, detects the voltage applied to the glow plug 4 by the voltage detection circuit, and corresponds the detected voltage value. By dividing by the current value, the resistance value R of the glow plug 4 being energized is measured (step S105).

  Then, the control unit 20 determines for each glow plug 4 whether or not the measured resistance value R has reached the target resistance value Rp unique to the glow plug 4 (step S106), and reaches the target resistance value Rp. With respect to the glow plug 4 that has reached the target resistance value Rp, the control unit 20 turns off the FET 31 corresponding to the glow plug, ends the energization to the glow plug 4, and individually controls the temperature maintenance. Migrate to

Here, the temperature maintenance control is control for energizing the glow plug 4 to maintain the temperature in the cylinder within a certain range. For example, an FET 31 is required so that the glow plug 4 always maintains the target resistance value Rp. Turn on at the duty ratio.
The fact that the heating resistor of each glow plug 4 has reached the target resistance value Rp means that the temperature, and thus the surface temperature of the glow plug 4, has reached the target temperature Tta. The engine can be started by ranking. When the driver performs a cranking start operation, the control shifts to energization control in the afterglow shown in FIG. Prior to the description of the energization control, the principle of measuring the intake air temperature in the present embodiment will be described.

[4] Principle of measuring the intake air temperature When cranking is performed several times to start the engine, outside air is introduced into the cylinder, so that the glow plug 4 maintained at the predetermined target temperature Tta is cooled. The glow plug 4 changes its resistance value in accordance with the resistance temperature coefficient of the resistance heating element. At this time, how much the resistance value changes, that is, how much the temperature decreases depends on the temperature of the outside air to be introduced.

  Accordingly, in a state where the glow plug 4 in the engine is preheated so as to reach a predetermined temperature, air of various temperatures is introduced into the cylinder, and the temperature change (resistance change) of the glow plug 4 at that time is preliminarily determined. If measured, the intake air temperature can be estimated. FIG. 5 is a graph showing the results of measuring the temperature change of the glow plug 4 when cold air of various temperatures is introduced into the cylinder while the glow plug 4 is maintained at a predetermined target temperature by performing preheating glow. It is shown. According to this, it can be seen that the difference in intake air temperature can be identified by measuring the temperature at least several seconds after cranking is started.

  Therefore, in the present embodiment, this experimental result is made into a data table in advance, the temperature of the glow plug 4 after a predetermined time has elapsed from the start of cranking, and the intake air temperature is detected based on the temperature difference. .

  As a specific configuration of the intake air temperature detecting means for that purpose, a post-cranking temperature difference calculating means, a storage means (not shown) such as an EPROM, and a reading means are provided. The post-cranking temperature difference calculating means is constituted by the CPU 21 included in the control unit 20, and calculates the preheating temperature of the glow plug 4 (that is, the “target temperature Tta” set at the time of controlling the preheating glow) and the cranking of the engine. The temperature difference with the post-cranking temperature when a predetermined time has elapsed from the start is obtained. In the storage means, the relationship between the intake air temperature and the temperature drop amount of the glow plug is tabulated and stored. In this data table, a plurality of types of air having different temperatures are introduced into the engine that has been preheated by cranking in advance, and the temperature drop amount of the glow plug 4 after a predetermined time has elapsed from the start of cranking is determined as glow plug temperature detecting means. It is obtained by detecting by. The reading means is constituted by the CPU 21 included in the control unit 20, and obtains the value of the intake air temperature corresponding to the temperature drop amount in the data table by obtaining the temperature drop amount detected by the glow plug temperature detection means. Has the function of reading.

[5] Energization control in afterglow Afterglow means that the glow plug 4 is energized and its temperature is kept high even after the engine is started. The energization control of the glow plug 4 when performing the after glow is performed by turning on the FET 31 at a required duty ratio so that the glow plug 4 always maintains a certain target temperature Tta. The detected actual temperature of the glow plug 4 is compared with the target temperature Tta. When the actual temperature is lower than the target temperature Tta, the duty ratio of energization is increased, and the actual temperature becomes the target temperature Tta. When it reaches, the duty ratio is reduced or the glow plug 4 is turned off.

In the present embodiment, when the afterglow is performed, the target temperature Tta is set as follows.
That is, when the glow plug 4 reaches the preheat glow target temperature Tta and the driver starts the cranking operation, first, the standard target temperature Tst is set as the afterglow target temperature Tta (step S121). . Then, when a predetermined time (for example, within a few seconds and before the ignition of fuel) has elapsed after the cranking is started, the temperature of the glow plug 4 is measured by the glow plug temperature detecting means (step S122). A temperature difference from the target temperature Tta is calculated (step S123). Based on the value, the intake air temperature Tin corresponding to the temperature difference recorded in the storage means is read (step S124). As a result, the intake air temperature Tin is estimated from the temperature change of the glow plug.

  Thereafter, it is determined whether or not the intake air temperature Tin is lower than a predetermined reference temperature Tref (step S125). If it is higher (in the case of “N”), the target temperature Tta is not changed. (Step S126) If the temperature is low (in the case of “Y”), the target temperature Tta after the change is set again by adding a predetermined value ΔT to the target temperature Tta at that time (standard target temperature Tst) ( Step S127), and thereafter, energization of the glow plug 4 in the afterglow is controlled based on the target temperature Tta (= Tta + ΔT). Here, the CPU 21 of the control unit 20 functions as target temperature setting means.

  Therefore, according to the present embodiment, when a situation occurs in which the engine is started in a very cold region and outside air having a very low temperature is sucked into the cylinder, the intake air temperature Tin is lower than the reference temperature Tref. Sometimes, since the target temperature of the glow plug 4 in the energization control of the after glow is set high, the temperature of the resistance heating element of the glow plug 4 is maintained higher than usual. As a result, even when more heat than usual is taken away from the surface of the glow plug 4 by the so-called swirl after starting, the temperature drop of the glow plug 4 can be suppressed, and the engine is stably operated. be able to.

  Further, when the intake air temperature Tin to the engine is higher than the reference temperature Tref (“N” in step S125), the afterglow target temperature Tta remains at the standard target temperature Tst, and therefore, the useless glow The power consumption for afterglow can be reduced without heating the plug 4. Thus, even if the target temperature Tta of the glow plug 4 is low, if the intake air temperature Tin is high, the cooling of the glow plug by the swirl is not so small that the engine can be operated stably.

  In the present embodiment, since the glow plug temperature detecting means for measuring the temperature of the glow plug 4 using the resistance heating element of the glow plug 4 itself is provided, a temperature sensor for measuring the temperature of the glow plug 4 is provided. There is no need to provide them separately. Further, the intake air temperature detecting means for detecting the intake air temperature Tin is also configured to detect the intake air temperature Tin based on the temperature change of the glow plug accompanying cranking by using the glow plug temperature detecting means. It is not necessary to separately provide a temperature sensor for measurement, and the configuration is simplified.

  In the glove lag temperature detecting means of the present embodiment, when the engine is started after being stopped for a long period of time, the resistance value of the glow plug 4 is measured and the variable R0 is initialized each time. . For this reason, even if the resistance temperature characteristic of the resistance heating element of the glow plug 4 changes due to aging, the current control can be correctly performed following the change.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above embodiment, the intake air temperature detecting means is configured to detect the intake air temperature using the temperature change of the glow plug 4 at the time of cranking. A temperature sensor may be provided at such a location, and the intake air temperature may be directly measured by the temperature sensor.

  (2) In the above embodiment, when the detected intake air temperature Tin is lower than the reference temperature Tref, the target temperature of the afterglow temperature is increased by ΔT. Thus, only one temperature threshold is used. However, the present invention is not limited to this, and a plurality of temperature thresholds may be provided to make the target temperature different from 3 or more. Further, the relationship between the intake air temperature Tin and the target temperature Tta can be described by a specific function (including a linear relationship), and the target temperature Tta is determined according to the detected intake air temperature Tin. In short, the target temperature Tta may be set higher as the intake air temperature Tin is lower.

  (3) In the above embodiment, the intake air temperature Tin is detected based on the temperature change of the glow plug 4 during cranking, and it is determined whether or not it is lower than the reference temperature Tref. A change in resistance value based on a temperature change of the glow plug 4 is detected, and the change in resistance value is compared with a reference value. If the change in resistance value is larger than the reference value, the target temperature during afterglow becomes higher. Change in the direction. This is because the resistance heating element of the glow plug 4 has a predetermined temperature resistance characteristic, and therefore, when the resistance change is large, it means that the intake air temperature is low.

  (4) In the above embodiment, when acquiring the intake air temperature Tin, the engine is cranked to use the temperature change of the glow plug 4 before the fuel is ignited. The intake air temperature can also be obtained by measuring the temperature change of the glow plug during idling of the engine. Since the fuel consumption during idling, and hence the amount of heat generated in the cylinder, is almost constant, how much the glow plug temperature decreases during idling due to the intake of cryogenic air also depends on the temperature of the intake air. This is because it can be grasped experimentally.

The block diagram of the energization control apparatus of the glow plug which concerns on one Embodiment of this invention. Flow chart showing preheat glow temperature control Flowchart showing variable initialization routine Flow chart showing afterglow temperature control Graph showing temperature change of glow plug 4 when engine is cranked at various intake air temperatures

4 ... Glow plug 20 ... Control unit (glow plug temperature detection means, intake air temperature detection means, target temperature setting means)
30 ... Switching unit (power control unit)
40. Reverse connection protection circuit

Claims (6)

A glow plug energization control device that performs after-glow by supplying power to a glow plug after starting a diesel engine, the glow plug temperature detecting means for detecting the temperature of the glow plug, and an energization path to the glow plug A power control unit configured to control power supplied to the glow plug so that a temperature detected by the glow plug temperature detection unit is set to a predetermined target temperature; and an intake air temperature to the diesel engine is detected. A glow plug energization control device comprising: an intake air temperature detection means; and a target temperature setting means for setting the target temperature higher as the intake air temperature is lower based on a signal from the intake air temperature detection means. The glow plug temperature detecting means includes resistance measuring means for measuring resistance when the glow plug is energized, and detects the temperature of the glow plug based on a temperature-resistance characteristic of a resistance heating element included in the glow plug. The glow plug energization control device according to claim 1. The intake air temperature detecting means is a glow plug preheat temperature measured by the glow plug temperature detecting means before the diesel engine cranking, and the glow plug changed by the intake operation accompanying the cranking of the diesel engine. The glow plug energization control device according to claim 1 or 2, wherein the intake air temperature is detected based on a post-cranking temperature. The intake air temperature detecting means includes a post-cranking temperature difference calculating means for obtaining a temperature difference between the preheat temperature and the post-cranking temperature when a predetermined time has elapsed after starting the cranking of the diesel engine; Storage means for storing the relationship between the obtained plurality of intake air temperatures and the temperature difference as a table, and the intake air temperature from the table stored in the storage means according to the temperature difference calculated by the post-cranking temperature difference calculation means 4. The glow plug energization control device according to claim 3, further comprising a reading means for reading out. In a glow plug energization control method for performing after glow so that the temperature of the glow plug is set to a predetermined target temperature by controlling power supplied to the glow plug after starting the diesel engine. A glow plug energization control method, wherein the target temperature is set higher as the intake air temperature is lower. The intake temperature of the diesel engine is calculated based on the preheat temperature of the glow plug before cranking of the diesel engine and the temperature after cranking of the glow plug changed by the intake operation accompanying cranking of the diesel engine. The energization control method for a glow plug according to claim 5, wherein:

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