JPH09291873A - Glow plug electrification controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glow plug electrification controller capable of detecting abnormalities of the electrification state to the glow plug without providing any special wire. SOLUTION: In an electronic controller for controlling electrification and non-electrification to a glow plug provided on a diesel engine by receiving voltage (battery voltage) from an on-vehicle battery, battery voltage VON in the electrification to the glow plug and battery voltage VOFF in the non- electrification to the glow plug are measured (S320, S350). When the difference between both voltages VOFF and VON (VOFF-VON) is less than the specified value VS (S360: YES), it is judged that abnormalities are generated on an electrification path of the glow plug, and an alarm lamp is lightened up (S370). The abnormality judging operation is not performed (S310: YES, S340: YES) in the situation in which battery voltage is fluctuated by a factor other than electrification and non-electrification to the glow plug.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energization control device for controlling energization / de-energization of a glow plug provided in an internal combustion engine, and in particular, it can detect whether or not the energization state of the glow plug is normal. The present invention relates to a glow plug energization control device.

[0002]

2. Description of the Related Art Conventionally, in a compression ignition type internal combustion engine typified by a diesel engine, a glow plug is arranged in a combustion chamber, and the glow plug is energized to generate heat before and when the engine is started. As a result, ignition and combustion of the fuel spray are promoted.

By the way, if the energizing circuit for energizing such a glow plug fails and the glow plug remains energized, a larger amount of electric power than the amount of power generated by the alternator mounted on the vehicle is generated. Has been consumed,
The battery may run out. On the contrary, if the glow plug becomes inoperable due to a failure of the energization circuit or a disconnection of the current supply path from the energization circuit to the glow plug, the startability of the internal combustion engine deteriorates. .

Therefore, conventionally, in an energization control device for controlling the energization of a glow plug, for example, a real fair 4-41.
As disclosed in Japanese Patent Publication No. 255-255, by directly monitoring the terminal voltage of the glow plug, it is possible to detect whether or not the energization state of the glow plug is normal.

[0005]

However, in the above-described conventional energization control device, a signal line (wire harness) for detecting the terminal voltage of the glow plug must be provided from the terminal of the glow plug to the device. However, there is a problem that the number of wires in the vehicle increases.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a glow plug energization control device capable of detecting an abnormality in the energization state of a glow plug without providing special wiring. Has an aim.

[0007]

Means for Solving the Problems and Effects of the Invention An energization control device according to claim 1, which has been made to achieve the above object, receives an electric power from a battery mounted on a vehicle to provide an internal combustion engine with the electric power. Controls energization / de-energization of the provided glow plug. In particular, in this energization control device, the first voltage detection means detects the battery voltage (that is, the voltage of the on-vehicle battery) when the glow plug is energized, and the second voltage detection means. Detects the battery voltage when the glow plug is not energized.
Then, the abnormality detecting means determines whether or not the difference between the voltage value detected by the second voltage detecting means and the voltage value detected by the first voltage detecting means is less than a predetermined value, and When the difference is less than the predetermined value, it is determined that an abnormality has occurred.

That is, since the value of the current flowing through the glow plug is normally large, such as 30 A to 60 A, the battery voltage drops when the glow plug is energized.
Therefore, the battery voltage has different values when the glow plug is energized and when it is not energized. On the other hand, if the glow plug remains energized for some reason, the battery voltage remains low and does not fluctuate even if the energization control device switches energization / de-energization to the glow plug. . Similarly, if energization to the glow plug is disabled for some reason, the battery voltage remains high and does not fluctuate even when the energization control device switches energization / de-energization to the glow plug. Therefore, in the energization control device according to claim 1, the battery voltage when energizing the glow plug and the battery voltage when deenergizing are respectively detected, and the battery voltage when deenergizing and the battery voltage when energizing are detected. If the difference is less than the predetermined value, it is determined that an abnormality has occurred.

Thus, according to the glow plug energization control device of the first aspect, it is possible to determine whether or not there is an abnormality by detecting the value of the battery voltage supplied from the vehicle-mounted battery to the device. Therefore, there is no need to provide special wiring as in the conventional device described above, and the glow plug has an abnormality in the energized state (that is, the glow plug has been left energized or has become unenergized). ) Can be detected.

Next, the energization control device according to claim 2 is different from the energization control device according to claim 1 in that a pre-starting energizing means is provided, and the pre-starting energizing means is an ignition switch of a vehicle. When is turned on, for a predetermined time,
Energize the glow plug. Then, the first voltage detection means detects the battery voltage at a predetermined timing within the predetermined time, and the second voltage detection means a predetermined timing after the energization to the glow plug by the pre-starting energization means is stopped. To detect the battery voltage.

That is, in the energization control device according to the second aspect, the glow plug is energized for a predetermined time after the ignition switch is turned on, and thereafter the starter switch of the vehicle is turned on and the internal combustion engine is turned on. The internal combustion engine can be quickly started when a starter motor (so-called cell motor) for starting the engine is activated. Then, the battery voltage is detected within a predetermined time during which the glow plug is energized as described above, and after the predetermined time has elapsed and the energization of the glow plug is stopped. If the difference is less than the predetermined value, it is determined that an abnormality has occurred.

Therefore, according to the energization control device of the second aspect, it is possible to detect whether or not the energization state of the glow plug is normal each time the occupant of the vehicle performs the starting operation of the internal combustion engine. Here, normally, in an internal combustion engine equipped with this kind of glow plug, in order to improve its startability, the glow plug is energized even when the starter switch of the vehicle is turned on and the starter motor is operating. I need to do it. In order to realize such an operation, a means for detecting that the starter switch is turned on and energizing the glow plug is additionally provided to the energization control device according to claim 2. Just go.

However, in the configuration in which the above-mentioned means is added, the above-mentioned predetermined time (that is, the period when the ignition switch is turned on and the glow plug is energized by the pre-start energizing means) has elapsed. If the starter switch is turned on after the battery voltage is detected by the second voltage detecting means, there is no problem, but if the starter switch is turned on within the predetermined time, the glow plug There is a possibility that it may not be possible to accurately determine whether the energized state is normal.

That is, when the starter switch is turned on within the above-mentioned predetermined time, the glow plug is continuously energized by the above-mentioned additional means.
The second voltage detecting means cannot detect the battery voltage when the glow plug is not energized. Then, even if the second voltage detecting means detects the battery voltage after the energization of the glow plug is stopped, the ripple from the alternator to the battery voltage does not occur after the internal combustion engine is started when the starter switch is turned on. Since the components and the like are superposed, the difference between the detected value by the first voltage detecting means and the detected value by the second voltage detecting means is caused by the factor of only energizing / de-energizing the glow plug. As a result, it becomes impossible to accurately determine the presence or absence of an abnormality.

Therefore, in order to solve such a problem, the structure as described in claim 3 may be adopted. First, the energization control device according to claim 3 includes a start control means in addition to the configuration according to claim 2, and the start control means detects whether or not a starter switch of the vehicle is turned on. Then, when it is determined that the starter switch is turned on,
The starter motor for starting the internal combustion engine is energized, and the glow plug is energized at least during energization of the starter motor.

Further, in particular, in the energization control device according to the third aspect, the start control permission means stops the energization of the glow plug by the pre-start energization means and the second voltage detection means detects the battery voltage. Then, the operation of the start control means is permitted. Moreover, when the detection control means detects the battery voltage by the first voltage detection means,
Start detecting whether the starter switch is turned on,
When it is detected that the starter switch is turned on before the predetermined time elapses after the ignition switch is turned on, the power supply to the glow plug by the pre-starting power supply means is forcibly stopped and the second The voltage detection means is made to detect the battery voltage.

According to the energization control device of the third aspect, the battery voltage when the glow plug is de-energized by the second voltage detecting means after the predetermined time has elapsed since the ignition switch was turned on. Is detected,
When the starter switch is turned on, the operation of the starter control means has already been permitted by the starter control permission means before the starter switch is turned on. Therefore, almost simultaneously with the starter switch being turned on, the starter control means is turned on. This starts energization of the starter motor and glow plug.

On the other hand, if the starter switch is turned on after the ignition switch is turned on and before the battery voltage when the glow plug is energized is detected by the first voltage detection means, the first voltage is detected. Immediately after the battery voltage is detected, the detection control means detects that the starter switch is turned on to forcibly stop the energization of the glow plug by the pre-starting energization means and the second voltage detection means. To be detected. Then, the start control permitting means permits the operation of the start controlling means even though the predetermined time has not elapsed, and as a result, the start controlling means starts energizing the starter motor and the glow plug. The Rukoto.

Further, if the starter switch is turned on before the predetermined time elapses after the battery voltage is detected by the first voltage detecting means, the starter switch is actually turned on. Almost at the same time, the detection control means detects that the starter switch is turned on, forcibly stops the energization of the glow plug by the pre-starting energization means, and causes the second voltage detection means to detect the battery voltage.
Also in this case, the start control permission means permits the operation of the start control means even though the predetermined time has not elapsed, and as a result, the start control means causes the starter motor and the glow plug to operate. Energization will be started.

That is, in the energization control device according to the third aspect, basically, when the starter switch is turned on, the starter motor and the glow plug are energized. When the starter switch is turned on within the energization time, the energization to the glow plug by the pre-starting energization means is forcibly stopped, the second voltage detection means is caused to detect the battery voltage, and then the starter motor is activated. The energization of the glow plug is restarted, and the energization of the glow plug is restarted. Further, the forced stop of the energization of the glow plug is performed after the battery voltage is detected by the first voltage detecting means. ing.

Therefore, according to the energization control device of the third aspect, the occupant of the vehicle turns on the starter switch within a certain period of time after the ignition switch is turned on until the predetermined time elapses. Even when the operation is performed, the battery voltage when the glow plug is energized and when the glow plug is de-energized is respectively determined by the first voltage detection means and the second voltage detection means while the starter motor and the internal combustion engine are not operating. You will be able to detect. In this way, even if the starter switch is turned on after the ignition switch is turned on, it is possible to accurately detect the battery voltage when the glow plug is energized and when it is not energized. Therefore, it is possible to reliably determine whether or not the energization state of the glow plug is normal each time the vehicle occupant starts the internal combustion engine.

Next, the energization control device according to claim 4 is
The energization control device according to any one of claims 1 to 3 is further provided with a status determination means and an abnormality detection prohibition means. Then, the status determination means determines whether or not the battery voltage may change due to a factor other than the energization / non-energization of the glow plug. If the status determination means makes an affirmative determination, the abnormality detection is performed. The prohibition means
The operation of the abnormality detection means is prohibited.

That is, in the energization control device according to the fourth aspect, when the battery voltage may fluctuate due to factors other than energization / non-energization of the glow plug, it is not determined whether or not an abnormality has occurred. I am trying. Therefore, according to the energization control device of the fourth aspect, it is possible to prevent erroneous determination of the presence or absence of abnormality.

By the way, as the situation judged by the situation judgment means (the situation in which the battery voltage may fluctuate due to a factor other than the energization / non-energization of the glow plug), for example, in the configuration according to claim 1 or 2, , The starter switch is on, the internal combustion engine is operating, the air conditioner switch is on, and the cooling water temperature of the internal combustion engine is extremely low. Further, in the configuration according to the third aspect, it is possible to reliably detect the abnormality even when the starter switch is turned on as described above, and therefore, there are situations (1) to (3) other than the above.

In the above situation, the battery voltage fluctuates due to energization of the starter motor. In the above situation, the ripple component from the alternator is superimposed on the battery voltage as described above. This is because various electric actuators are driven during operation of the internal combustion engine. Also, regarding the above situation,
This is because the fan motor of the air conditioner, the motor for switching ducts, etc. may operate, and in the above situation, the output capacity of the battery itself decreases at low temperatures and the battery voltage becomes unstable. is there.

Next, in the energization control device according to the fifth aspect, the energization control device according to any one of the first to fourth aspects is provided with informing means, and the informing means is abnormal. When it is determined by the detection means that an abnormality has occurred, the occupant of the vehicle is notified of the occurrence of the abnormality.
Then, according to this energization control device, the occupant of the vehicle can be surely informed of the occurrence of the abnormality, and in turn, the repair can be promptly performed.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. It is needless to say that the embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.

[First Embodiment] FIG. 1 is a schematic configuration diagram showing the overall configuration of an engine control system of a first embodiment for controlling the operation of a vehicle diesel engine. As shown in FIG. 1, the engine control system of the first embodiment is
An electronic control unit that operates by receiving the voltage (hereinafter, referred to as battery voltage) VB of a battery 1 mounted on a vehicle (hereinafter, referred to as "
(Referred to as ECU) 3, a power supply relay 5 that supplies the battery voltage VB to the ECU 3 via a power supply line + B, and a glow plug 7 that applies the battery voltage VB to a glow plug 7 provided in each cylinder of a diesel engine (not shown). The relay 9 and the diesel engine are provided to start the vehicle, and when the key switch 11 of the vehicle reaches the start position ST, the battery voltage VB is transmitted via the key switch 11.
Is provided with a starter motor 13 and a warning lamp 17 which is arranged in the meter panel of the vehicle and is turned on by the ECU 3.

The key switch 11 is of a well-known cylinder type in which a key is inserted by a vehicle occupant to be operated sequentially from the off position OFF to the ignition position IG, and further from the ignition position IG to the start position ST. Therefore, when the start position ST is being operated, both the contact at the start position ST and the contact at the ignition position IG are both connected to the battery 1.

On the other hand, the ECU 3 is a CPU 2 which executes various arithmetic processing for controlling the diesel engine.
1 and the battery voltage VB from the power supply line + B are input to supply a predetermined power supply voltage (for example, 5 V) Vcc to the CPU 21 and the operating position of the key switch 11 by the vehicle occupant. , An input buffer 25 connected to each contact of the key switch 11 (contact at ignition position IG and contact at start position ST)
And the voltage of power supply line + B (that is, battery voltage VB)
A / D that converts the signal into a digital signal and outputs it to the CPU 21
According to a drive command from the conversion circuit (hereinafter referred to as ADC) 27 and the CPU 21, each contact of the power relay 5 and the glow relay 9 is short-circuited, and the warning lamp 1 is also provided.
And an output circuit 29 for turning on the light.

Although not shown in FIG. 1, the ECU
Signals from various sensors for detecting the operating state of the engine, such as a crank angle sensor that detects the number of revolutions of a diesel engine (hereinafter simply referred to as an engine) and a water temperature sensor that detects the cooling water temperature of the engine, are shown in 3. Input buffer for inputting, input buffer for inputting signals from operating switches of various electrical components such as operation switch of vehicle air conditioner (air conditioner), brake switch that is turned on when the brake pedal is depressed, and engine control An output circuit that outputs a drive signal to various actuators in response to a drive command from the CPU 21 is provided.

When the supply of the power supply voltage Vcc is started, the power supply circuit 23 holds the reset signal RST to the CPU 21 at a low level for a certain period of time until the power supply voltage Vcc is reliably stabilized, and the CPU 21 is initialized. Call
It has a well-known initial reset function.

The output circuit 29 basically uses the battery voltage VB from the power supply line + B as a power source,
In response to a drive command from U21, an exciting current is supplied to the coils of the relays 5 and 9 to short-circuit the contacts of the corresponding relays.
The battery voltage VB is also supplied through the contact at the ignition position IG of the key switch 11. And
Regarding the power supply relay 5, the output circuit 29 receives the battery voltage VB directly from the key switch 11 when the key switch 11 is operated to the ignition position IG.
The excitation current is supplied to the coil of the power relay 5 regardless of the drive command from the CPU 21.

Furthermore, the output circuit 29 is constructed so as to flow an exciting current to the coil of the glow relay 9 when a drive command for opening and closing the contacts of the glow relay 9 is output from the CPU 21 at a low level. , And C
Among the output ports of the PU 21, the output level of the port that outputs the drive command corresponding to the glow relay 9 is at the low level at the time of reset (that is, the level at which the contacts of the glow relay 9 are short-circuited). Therefore, power relay 5
Is short-circuited and the supply of the battery voltage VB from the power supply line + B to the ECU 3 is started, then the CPU 21
The excitation circuit outputs the exciting current from the output circuit 29 to the coil of the glow relay 9 until it starts to operate and outputs the drive command corresponding to the glow relay 9 at a high level.

Next, the overall operation of the electronic control system thus configured will be described. In the following description, turning on the ignition switch IG means that the key switch 11 is in the off position OFF to the ignition position I.
When the start switch ST is turned on, the key switch 11 is operated from the ignition position IG to the start position ST to operate the ignition position IG. And the contact at the start position ST are both connected to the battery 1. And furthermore
The ON / OFF of the relays 5 and 9 means that the contacts of the corresponding relay are short-circuited / opened.

First, when the vehicle occupant turns on the ignition switch IG, the battery voltage VB is supplied to the output circuit 29 in the ECU 3 via the key switch 11, and as described above, the output circuit 29 outputs the power relay 5 to the power relay 5. Exciting current is output to the coil. Then, the power supply relay 5 is turned on, and the battery voltage VB is supplied to the ECU 3 via the power supply line + B.

Then, in the ECU 3, the power supply circuit 23 starts the supply of the power supply voltage Vcc to the CPU 21, and outputs the reset signal RST to the CPU 21 from the start of the supply until the predetermined time elapses. The CPU 21 is held at a low level (see RST in FIG. 5), and the CPU 21 is initialized. In addition, the ignition switch IG is turned on in this way, and the power line + B
When the supply of the battery voltage VB to the battery 3 is started, as described above, the exciting current is output from the output circuit 29 to the coil of the glow relay 9, and the glow relay 9 is turned on. VB is applied,
Energization of the glow plug 7 is started (see GOUT in FIG. 5).

After that, when the reset signal RST from the power supply circuit 23 changes from low level to high level, CP
By starting the operation of U21 and executing the processing of FIGS. 2 to 4 which will be described later, the energization / de-energization of the glow plug 7 (short-circuiting / opening of the glow relay 9) is controlled, and the glow plug 7 is operated. It is determined whether or not the energized state is normal. Further, when the engine is operated by the starter motor 13, the CPU 21 executes various arithmetic processing for controlling the engine based on signals from various sensors, operation switches, etc., to optimize the operating state of the engine. To do.

On the other hand, when the vehicle occupant turns off the ignition switch IG to stop the engine, the supply of the battery voltage VB from the key switch 11 to the output circuit 29 is stopped. However, the CPU 21 in the ECU 3 outputs a drive command for turning on the power supply relay 5 to the output circuit 29 immediately after the operation is started, and even after detecting that the ignition switch IG is turned off, a predetermined time ( The power relay 5 is continuously turned on only for 2 seconds, for example. Then, the CPU 21 narrows the opening of the intake control valve provided in the intake system of the engine to stop the engine quickly within this time, and then turns off the power supply relay 5 to the output circuit 29. Output a drive command for power supply line + B
The supply of the battery voltage VB to the CU3 is cut off by itself, and the operation of the entire system is stopped.

Next, the processing executed by the CPU 21 immediately after reset release for controlling the energization / de-energization of the glow plug 7 will be described with reference to the flow charts shown in FIGS. The processes of FIGS. 2 to 4 are executed in parallel. Further, as described above, the glow relay 9 has already been turned on before the execution of each of these processes is started (that is, from the time when the ignition switch IG is turned on). Furthermore, in each of the flowcharts used in the following description, the process of turning on the relay is to hold the corresponding relay in the ON state thereafter, and similarly, the process of turning off the relay is thereafter applied. It keeps the relay in the off state.

First, FIG. 2 shows a first glow control process for performing so-called preheat glow control, in which the glow plug 7 is previously energized to generate heat before the engine is started to improve the engine startability. It is a flowchart.
As shown in FIG. 2, when the CPU 21 starts to operate, first, in step (hereinafter, simply referred to as S) 110, a pre-starting energization time Ta is set, which represents a time for continuing energization of the glow plug 7. At the same time, the timing of the time Ta is started, and it is determined in S120 that the starter switch ST has been turned on. And the starter switch ST
If is not turned on, the process proceeds to S130, and it is determined whether or not the pre-starting energization time Ta has elapsed. If the time Ta has not elapsed, the process returns to S120.

On the other hand, in S130, the pre-start energization time Ta
If it is determined that the glow relay 9 has passed, the process proceeds to S140, and the glow relay 9 is turned off by outputting the drive command corresponding to the glow relay 9 to the output circuit 29 at a high level as described above. Stop energizing the plug 7. Then, after executing the processing of S140,
The first glow control process is ended.

Further, in S120, the starter switch S
When it is determined that T is turned on, the first glow control process is ended without turning off the glow relay 9. That is, in the first glow control process, the CPU 21
If the starter switch ST is not turned on during the period from the start of the operation until the pre-starting energization time Ta elapses, the energization to the glow plug 7 is stopped when the pre-starting energization time Ta elapses. (S120: N
O, S130: YES, S140). Then, in the first embodiment, the time from when the ignition switch IG is turned on to when the energization of the glow plug 7 is stopped in the process of S140, that is, the CPU 21 is operated after the ignition switch IG is turned on. The time obtained by adding the time until the start of and the pre-start energization time Ta corresponds to the predetermined time according to claim 2, and the output circuit 29 and the processing of S110, S130, and S140 in FIG. Corresponds to the pre-starting energizing means.

The time from when the ignition switch IG is turned on to when the CPU 21 starts operating (that is, the initial reset time) is set to about 0.2 seconds at maximum, and the pre-start energization time Ta is set. Is set to about 5 to 10 seconds. Therefore, the time until the CPU 21 starts the operation can be ignored, which is sufficiently smaller than the pre-start energization time Ta, and the energization time to the glow plug 7 can be managed by the pre-start energization time Ta. .

Next, FIG. 3 is a flow chart showing a second glow control process executed to control the energization of the glow plug 7 after the starter switch ST is turned on. As shown in FIG. 3, when the CPU 21 starts executing the second glow control process, first, in S210, it is determined whether or not the starter switch ST is turned on. If the starter switch ST is turned on, the glow relay 9 is turned on to energize the glow plug 7 in S220, and then the process returns to S210.

Therefore, when the starter switch ST is turned on after S140 of the first glow control process is executed (that is, after the pre-start energization time Ta has elapsed), the glow relay 9 causes the glow relay 9 to perform the above S220. When the starter switch ST is turned on before the above S140 is executed (that is, before the pre-start energization time Ta elapses) by the process
The glow relay 9 is continuously turned on after the ignition switch IG is turned on.

On the other hand, in S210, the starter switch S
When it is determined that T is not on, the process proceeds to S230, and it is determined whether or not it is immediately after the starter switch ST changes from on to off, and immediately after the starter switch ST changes from on to off. If not, the state of the glow relay 9 is not changed and the process directly returns to S210.

On the other hand, if it is determined in S230 that the starter switch ST has just changed from ON to OFF, the process proceeds to S240, in which the engine speed NE is changed.
Is greater than the predetermined number of revolutions M, it is determined whether the engine has been started in response to the starter switch ST being turned on and the starter motor 13 being operated. Then, when it is determined that the engine has started, the energization time Tb after starting is set in the subsequent S250, and the time counting of the time Tb is started, and the subsequent S260.
At, the system waits until the energization time Tb has elapsed after the start. When it is determined in S260 that the post-starting energization time Tb has elapsed, the process proceeds to S270, the glow relay 9 is turned off, and then the process returns to S210.

If it is determined in S240 that the engine has not started, the process proceeds to S280, the restart energizing time Tc is set, and the time Tc is counted. Then, in subsequent S290, it is determined whether or not the starter switch ST is turned on. If the starter switch ST is not turned on, the process proceeds to S300,
It is determined whether or not the restart energizing time Tc has elapsed, and if the time Tc has not elapsed, the process returns to S290. When it is determined in S300 that the restart energizing time Tc has elapsed, the process proceeds to S270, the glow relay 9 is turned off, and then the process returns to S210. On the other hand, S290
When it is determined that the starter switch ST is turned on, the process proceeds to S220 and the glow relay 9 continues.
Is turned on, and then the process returns to S210.

That is, in the second glow control process, the glow plug 7 is energized while the starter switch ST is turned on and the starter motor 13 is operating to improve the startability of the engine. (S21
0: YES, S220). And the starter switch S
If the engine is started when T is turned off (S2
40: YES), after that, until the energization time Tb after start-up elapses, energization of the glow plug 7 is continued to promote ignition and combustion of the fuel spray to stabilize the operation of the engine. (S250-
S270), or if the engine has not started (S240: NO), then starter switch ST
Is expected to be turned on again, the energization of the glow plug 7 is continued until the restart energization time Tc elapses (S280 to S300,
S270).

Next, FIG. 4 shows an abnormality detection process peculiar to the engine control system of the first embodiment, which is executed to determine whether or not the energization state of the glow plug 7 is normal. It is a flowchart. As shown in FIG.
When the PU 21 starts to operate and starts to execute the abnormality detection process, first, in S310, a process as a situation determination means for determining whether any one of the following conditions (1) to (3) is satisfied is executed. To do.

The starter switch ST is turned on. The engine speed NE is not 0 [rpm] (the engine is operating). The air conditioner switch is turned on. The engine coolant temperature is extremely low.

If it is determined in S310 that all of the above conditions (1) to (4) are not satisfied, the process proceeds to S320, in which the current power supplied from the power supply line + B is supplied based on the digital signal from the ADC 27. Battery voltage VB
Is measured, and the measured value is the battery voltage when the glow plug 7 is energized (hereinafter, referred to as on-time voltage).
The processing as the first voltage detection means, which is stored as VON, is executed.

Then, in the subsequent S330, the above-mentioned first
In S140 of the glow control process or S270 of the second glow control process, it is determined whether or not the glow relay 9 is turned off, and the process waits until the glow relay 9 is turned off. S33
When it is determined that the glow relay 9 is turned off at 0, S3
Proceeding to 40, just as in the case of S310 described above,
When it is determined that all of the above conditions (1) to (3) are not satisfied by executing processing as a situation determination means that determines whether any one of the above conditions (1) is satisfied, S3 is performed.
Go to 50. Then, in S350, the current battery voltage VB supplied from the power supply line + B is measured based on the digital signal from the ADC 27, and the measured value is
It is stored as a battery voltage (hereinafter, referred to as an off-state voltage) VOFF when the glow plug 7 is not energized,
The processing as the second voltage detecting means is executed.

Then, in the following S360, it is determined whether or not the difference (VOFF-VON) between the off-time voltage VOFF stored in S350 and the on-time voltage VON stored in S320 is less than a preset predetermined value VS. The difference (VOFF-VON) is determined to be a predetermined value V by executing processing as abnormality detecting means for determining
If it is less than S, it is determined in S370 that some abnormality has occurred in the energization path to the glow plug 7, the warning lamp 17 is turned on, and an abnormality is indicated in the backup RAM inside the CPU 21. A process as an informing unit for setting an abnormal code is executed. Then, after that, the abnormality detection process ends.

When it is determined in S360 that the difference (VOFF-VON) between the off-time voltage VOFF and the on-time voltage VON is not less than the predetermined value VS, the process proceeds to S380, and in this S380. It is determined that the energization state of the glow plug 7 is normal, and then the abnormality detection process ends.

In the above S360, the off-time voltage VOFF is
The difference between the on-state voltage VON (VOFF-VON) is the predetermined value V
Even if it is not less than S, if it greatly exceeds the normally possible value, it is determined that an abnormality has occurred, and the process proceeds to S370.
On the other hand, when it is determined in S310 or S340 that any one of the above conditions (1) to (3) is satisfied, the process proceeds to S380 without executing other processes.
The process as the abnormality detection prohibition means is executed, and then S3
After making a normal determination at 80, the abnormality detection process is terminated.

Here, by executing the above abnormality detection processing,
How to detect the abnormality will be described with reference to FIG. It should be noted that in FIG. 5, the starter switch ST is not turned on after the ignition switch IG is turned on until the CPU 21 starts operating and the above-described pre-start energization time Ta elapses (the above condition is satisfied. No), and moreover, the operation when all of the above-mentioned conditions 1 to 3 are not satisfied is shown. And in FIG.
“IG” represents the on / off state of the ignition switch IG, and “RST” represents the power supply circuit 23 to the CPU 2
1 represents a reset signal RST to "1", "GOUT" represents an exciting current from the output circuit 29 to the glow relay 9 (that is, the ON / OFF state of the glow relay 9), and "VG" represents
The voltage applied to the glow plug 7 when the glow relay 9 is turned on is represented, and “+ B” represents the voltage of the power supply line + B.

First, as shown at time t1 in FIG. 5, when the ignition switch IG is turned on by the vehicle occupant, as described above, the battery voltage VB is supplied to the ECU 3 through the power supply line + B and the ECU 3 The output circuit 29 and the hardware of the CPU 21 turn on the glow relay 9 and start energizing the glow plug 7.

When a certain period of time has passed, time t2
As shown in, the initial reset for the CPU 21 is released, and the CPU 21 starts execution of the first glow control processing, the second glow control processing, and the abnormality detection processing. Then, the CPU 21 immediately after the time t2, the power supply line + B.
Is measured (that is, the ON-time voltage VON) (S32
0) After that, when the pre-start energization time Ta set in S110 of the first glow control process has elapsed, the glow relay 9 is turned off and the energization of the glow plug 7 is stopped, as shown at time t3.

The timing at which the CPU 21 starts the execution of each of the above processes is set to a predetermined timing after the on-state voltage VON is stably measured. Therefore, depending on the operation response of the glow relay 9 or the like, the CPU 21 may start the execution of each of the above processes after a lapse of a predetermined time after the initial reset is released. Then, as shown at time t4, the CPU 21
At a predetermined timing after the power supply to the glow plug 7 is stopped, the voltage of the power supply line + B (that is, the off-time voltage V
OFF) is measured (S350), and the difference between the off-state voltage VOFF and the on-state voltage VON thus measured (VOFF-VON)
Is less than a preset predetermined value VS (for example, 1.0 V) (S360). If the difference (VOFF-VON) is not less than the predetermined value VS, it is determined that the glow plug 7 is normally energized (S36).
0: NO, S380), conversely, the difference (VOFF-VON)
Is less than the predetermined value VS, it is determined that an abnormality has occurred and the warning lamp 17 is turned on (S360: YES,
S370).

That is, since the value of the current flowing through the glow plug 7 is usually as large as 30 A to 60 A, when the glow relay 9 is turned on, the battery voltage VB is changed from 12 V, for example, as shown in FIG. 6A. It drops to 10.8V. Therefore, if the energization path to the glow plug 7 is normal, the battery voltage VB has a different value when the glow relay 9 is on and when it is off (that is, when the glow plug 7 is energized and de-energized). .

On the other hand, if the glow plug 7 remains energized due to, for example, a short-circuit failure of the contact of the glow relay 9, the ECU 3 causes the glow plug 7 to glow as illustrated in FIG. 6B. Even if the relay 9 is switched on / off, the battery voltage VB remains low (10.8 V) and does not fluctuate. Similarly, if the contact of the glow relay 9 is opened and the energization of the glow plug 7 becomes impossible, as shown in FIG.
Even if U3 switches the glow relay 9 on and off, the battery voltage VB remains high (12 V) and does not fluctuate.

Therefore, in the ECU 3 of the first embodiment, C
When the PU 21 executes the abnormality detection process of FIG. 4,
The battery voltage (ON voltage VON) when the glow plug 7 is energized and the battery voltage (OFF voltage VOFF) when the glow plug 7 is not energized are respectively detected, and the difference (VOFF) between the detected values is detected. If -VON) is less than the predetermined value VS, it is determined that an abnormality has occurred.

As described above, according to the ECU 3 of the first embodiment, by detecting the value of the battery voltage VB supplied from the battery 1 via the power supply line + B,
Since it is determined whether or not there is an abnormality, it is not necessary to additionally provide a special wiring, and therefore the abnormality in the energized state of the glow plug 7 (that is, whether the glow plug 7 remains energized, or , It has become impossible to energize).

On the other hand, in the ECU 3 of the first embodiment, the above-mentioned steps are performed in S310 or S340 of the abnormality detection processing.
When it is determined that any one of the above conditions is satisfied, it is not determined whether or not an abnormality has occurred. That is, as described in the section “Means for Solving the Problem and Effects of the Invention”, in the situation where the above conditions (1) to (3) are satisfied, the glow plug 7 is energized and
Since the battery voltage VB may fluctuate due to factors other than non-conduction, the determination as to whether an abnormality has occurred is not made.

Therefore, according to the ECU 3 of the first embodiment, it is possible to prevent the presence or absence of abnormality from being erroneously determined. Further, in the ECU 3 of the first embodiment, the warning lamp 17 is turned on when it is determined that an abnormality has occurred. Therefore, the occupant of the vehicle can surely know the occurrence of the abnormality, and in turn, the repair can be promptly performed.

By the way, in the ECU 3 of the first embodiment, as described above, when the starter switch ST is turned on (when the above condition is satisfied), it is not judged whether or not there is an abnormality. . Therefore, a sufficient time (that is, the time from when the CPU 21 starts the operation to the end of the execution of the first glow control processing and the abnormality detection processing) has elapsed since the occupant of the vehicle turned on the ignition switch IG. After that, if the starter switch ST is turned on, the ECU 3 can detect whether or not the energization state of the glow plug 7 is normal each time such a starting operation is performed.

However, conversely speaking, after the vehicle occupant turns on the ignition switch IG, the CP
If a quick start operation such as turning on the starter switch ST is performed before the timing of the pre-start energization time Ta by U21 is completed, it becomes impossible to detect the presence or absence of an abnormality.

Therefore, as a second embodiment, whether the starter switch ST is turned on or not at any timing after the ignition switch IG is turned on, whether or not the energization state to the glow plug 7 is normal is determined. An engine control system capable of surely determining whether or not is described.

[Second Embodiment] First, FIG. 7 is a schematic configuration diagram showing an overall configuration of an engine control system of a second embodiment. As shown in FIG. 7, the engine control system of the second embodiment is different from the engine control system of the first embodiment shown in FIG. 1 in that a starter relay 15 for applying a battery voltage VB to the starter motor 13 is provided. It is additionally prepared. Then, in the second embodiment, the output circuit 29 in the ECU 3 causes an exciting current to flow to the coil of the starter relay 15 in response to a drive command from the CPU 21, thereby short-circuiting the contact of the starter relay 15 ( (Turning it on), thereby operating the starter motor 13. That is, the operation / non-operation (energization / non-energization) of the starter motor 13 is controlled by the ECU 3.

Further, in the engine control system of the second embodiment, in the engine control system of the first embodiment, the CPU 21 replaces each processing shown in FIGS. The processes of FIG. 10 are executed. That is, in the second embodiment, the first glow control process is executed as shown in FIG. 8, the second glow control process is executed as shown in FIG. 9, and the abnormality detection process is executed as shown in FIG. To be executed.

Therefore, the processing executed by the CPU 21 in the ECU 3 in the engine control system of the second embodiment will be described below with reference to FIGS. FIG.
In FIG. 10, the same steps as those in the first embodiment are designated by the same step numbers, and detailed description thereof will be omitted. In addition, in the second embodiment, FIGS.
The execution of each process shown in (1) is not started simultaneously, but the execution of the abnormality detection process (FIG. 10) is started first. Then, as will be described later, the execution start of the first glow control processing (FIG. 8) and the second glow control processing (FIG. 9) in the abnormality detection processing is permitted.

First, as shown in FIG. 8, in the first glow control process executed in the second embodiment, the process of S120 is performed in contrast to the first glow control process executed in the first embodiment (FIG. 2). Instead of this, the processing of S125 is executed. Then, in S125, similarly to S120 described above, it is determined whether or not the starter switch ST is turned on. However, when it is determined that the starter switch ST is turned on, the first glow control process is directly executed. Instead of ending, the process proceeds to S140. Then, in S140,
After turning off the glow relay 9, the first glow control process is ended.

Next, as shown in FIG. 9, in the second glow control process executed in the second embodiment, in S225, in contrast to the second glow control process executed in the first embodiment (FIG. 3). The process and the process of S228 are additionally executed. That is, in the second glow control process of the second embodiment, S2
When it is determined that the starter switch ST is turned on in 10 or S290, the glow relay 9 is turned on in S220, and the starter relay 15 is turned on in the additional S225.
I'm trying to turn on. Further, when it is determined in S210 that the starter switch ST is not on (off), the starter relay 15 is added in the additional S228.
After turning off, the process proceeds to S230.

As described above, in the second glow control process of the second embodiment, the starter relay 15 is turned on to energize the starter motor 13 while detecting that the starter switch ST is turned on. I am trying to do it. still,
In S225, the process of turning on the starter relay 15 only when the engine speed NE is equal to or less than a predetermined value may be executed. Further, in the second embodiment, S210, S220, S of the second glow control process are performed.
225 corresponds to the starting control means.

Next, the abnormality detection processing executed in the second embodiment will be described. As shown in FIG. 10, in the abnormality detection processing of the present embodiment, first, in S315, processing as status determination means for determining whether or not any one of the conditions (1) to (3) other than the above is satisfied. To execute. When it is determined that the above conditions (1) to (4) are not all satisfied, the process proceeds to S320, and the battery voltage (ON-time voltage VON) when the glow plug 7 is energized is measured.

Here, in the second embodiment, if the on-time voltage VON is measured in S320, or if it is determined in S315 that any one of the above conditions (1) to (3) is satisfied, the process proceeds to S325. After the transition, the execution start of the first glow control process (FIG. 8) is permitted. Therefore, from this point
The execution of the glow control process is started.

Then, in the next S330, the first
When it is determined in S140 of the glow control process that the glow relay 9 has been turned off, it is determined in subsequent S345 whether or not any one of the above conditions (1) to (3) is satisfied, just as in the case of S315. When the processing as the determination means is executed and it is determined that the above conditions (1) to (3) are not all satisfied, S350 is performed in the same manner as in the first embodiment.
At, the battery voltage when the glow plug 7 is not energized (off-time voltage VOFF) is measured, and an abnormality determination regarding the energized state of the glow plug 7 is performed by subsequent S360 and S370 or S380.

When it is determined in S345 that any one of the above conditions (1) to (3) is satisfied, the process proceeds to S380 without executing the processes of S350 and S360 as in the case of the first embodiment. To do. Then, when the processing of S350 and S360 and S370 or S380 is executed,
The process proceeds to S390, a process as a start control permitting unit that permits the execution start of the second glow control process (FIG. 9) is performed, and then the abnormality detection process ends. Therefore, the execution of the second glow control process is started from this point.

The processing of S315 and S345 is as shown in FIG.
It is provided in place of S310 and S340. Then, in the processing of S315 and S345, it is determined whether or not the conditions (1) to (3) other than the above (the starter switch ST is on) are satisfied. This is because the processing of S320 and S350 to S370 is executed even if it is performed.

As described above, in the engine control system of the second embodiment, in S210 of the second glow control process,
When it is determined that the starter switch ST is turned on, S
Although both the glow relay 9 and the starter relay 15 are turned on by 220 and S225, the execution of such second glow control processing is started after the abnormality detection processing is substantially completed (FIG. 10 S390).

Therefore, if all of the above conditions (1) to (3) are not satisfied, the on-state voltage VON and the off-state voltage VOFF are measured in the abnormality detection process, and the presence or absence of abnormality is determined based on the difference (VOFF-VON). Even if the starter switch ST is turned on before the determination, the glow relay 9 and the starter relay 15 are not turned on immediately, but are turned on after the presence or absence of abnormality is determined by the abnormality detection processing.

Further, in the engine control system of the second embodiment, when it is determined in S125 of the first glow control process that the starter switch ST is turned on, S1 is set.
The glow relay 9 is forcibly turned off by 40. Therefore, in this case, even if the above-described pre-start energization time Ta has not elapsed, a positive determination is made in S330 in the abnormality detection processing, and the processing for abnormality determination after S340 is executed.

Moreover, since the first glow control process is started after the on-time voltage VON is measured in the abnormality detection process (S325 in FIG. 10), the starter switch ST
The determination in S125 as to whether or not is turned on is naturally started after the on-time voltage VON is measured.
Therefore, even if the starter switch ST is turned on before the ON-time voltage VON is measured in the abnormality detection processing, the glow relay 9 is not immediately turned OFF, and the ON-time voltage VON is detected in the abnormality detection processing. After being measured, it is turned off, and the on-time voltage VON is reliably measured. And
In the second embodiment, S12 of the first glow control process is performed.
5 corresponds to the detection control means.

Here, how the abnormality is detected by executing the above-mentioned processes will be described with reference to FIG. In addition, in FIG. 11, the starter switch ST is turned on from the time when the ignition switch IG is turned on to the time when the pre-starting energization time Ta is finished in the first glow control process. It shows the operation when all the conditions are not satisfied. Further, in FIG. 11, “ST” is the starter switch S.
Indicates the on / off state of T, and "SOUT" is the output circuit 2
9 shows the exciting current from 9 to the starter relay 15 (that is, the on / off state of the starter relay 15), and the others are the same as in FIG.

First, as shown at time t1 in FIG. 11, when the ignition switch IG is turned on, the battery voltage VB is supplied to the ECU 3 via the power supply line + B, and the glow relay 9 is turned on. And time t
When the reset of the CPU 21 is released as shown in 2, C
The PU 21 first starts executing the abnormality detection process.

Then, immediately after the time t2, the CPU 21 measures the voltage of the power supply line + B (that is, the on-time voltage VON) (S320), and further starts the execution of the first glow control process from this time (S320). S325). And time t
As shown in FIG. 5, when the starter switch ST is turned on before the pre-start energization time Ta set in S110 of the first glow control process has elapsed, the CPU 21 forcibly turns off the glow relay 9 (S125. : YES, S14
0). Further, as shown at time t6, the CPU 21
Is again the voltage of the power supply line + B (that is, the off-time voltage V
OFF) is measured (S330: YES, S350), and the difference between this OFF-time voltage VOFF and ON-time voltage VON (VOFF-V
Whether there is an abnormality is determined based on (S360 to S38).
0).

Immediately thereafter, the CPU 21 starts execution of the second glow control process (S390), and turns on the glow relay 9 and the starter relay 15 as shown at time t7 (S210: YES, S220, S225). . And
This starts the engine.

FIG. 11 shows a case where the starter switch ST is turned on from the time when the on-time voltage VON is measured in step S320 of the abnormality detection process until the pre-start energization time Ta elapses. However, if the starter switch ST is turned on after the ignition switch IG is turned on and before the on-time voltage VON is measured in S320, the on-time voltage VON is measured in S320. Immediately after the start, the start of the starter switch ST is detected in S125 of the first glow control process, and the glow relay 9
Is turned off. Then, after that, the same operation is performed after the time t5 in FIG.

On the other hand, when the starter switch ST is turned on after the execution of the abnormality detection process after the pre-start energization time Ta has elapsed, the execution of the second glow control process has already been started before that. Therefore, at the same time when the starter switch ST is turned on, the starter relay 15
Also, the glow relay 9 is turned on and the energization of the starter motor 13 and the glow plug 7 is started. That is, in this case, the operation is exactly the same as that of the first embodiment described above.

As described above, in the second embodiment, basically, when the starter switch ST is turned on, the starter motor 13 and the glow plug 7 are energized, but the pre-start energization time Ta is measured. If the starter switch ST is turned on by the end of, the glow plug 7
The power supply to the glow plug 7 is forcibly stopped, the off-time voltage VOFF is measured, and then the power supply to the starter motor 13 is started and the power supply to the glow plug 7 is restarted. Forcibly stop the energization of the plug 7,
It is always executed after measuring the on-time voltage VON.

Therefore, according to the engine control system of the second embodiment, even when the occupant of the vehicle performs a quick start operation such as turning on the ignition switch IG and then immediately turning on the starter switch ST, With the starter motor 13 and engine not operating,
The ON-time voltage VON and the OFF-time voltage VOFF can be measured respectively. As described above, even if the starter switch ST is turned on at any timing, the on-time voltage VON and the off-time voltage VOFF can be accurately detected, so that the occupant of the vehicle can operate the engine. Each time the starting operation is performed, it can be reliably determined whether or not the energization state of the glow plug 7 is normal.

Also in the second embodiment, if it is determined in S315 or S345 of the abnormality detection process that any one of the above-mentioned conditions (1) to (3) is satisfied, an abnormality has occurred. It does not judge whether or not. Therefore, it is possible to prevent the presence or absence of abnormality from being erroneously determined.

[Others] In each of the above-described embodiments, when the abnormality is detected once in S360 and S370 of the abnormality detection processing, the warning lamp 17 is turned on and the abnormality code is stored in the backup RAM. Only when it is determined that an abnormality has occurred a plurality of times in succession, it is possible to determine that an abnormality has really occurred and to turn on the warning lamp 17, etc., thereby enabling more reliable abnormality detection.

As described above, in each of the above embodiments, the power relay 5 is turned on for a predetermined time (2 seconds) after the ignition switch IG is turned off. Therefore, the glow relay 9 is turned on / off during that time. Alternatively, the abnormality detection may be performed. With this configuration, it becomes possible to determine whether or not there is an abnormality both when the occupant of the vehicle turns on the ignition switch IG and when it turns off the ignition switch IG.

On the other hand, in each of the above embodiments, the CPU 21
When detecting an abnormality, the drive command for turning off the glow relay 9 may be output to the output circuit 29.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an overall configuration of an engine control system of a first embodiment.

FIG. 2 is a flowchart showing a first glow control process executed by an electronic control unit (ECU) shown in FIG.

FIG. 3 is a flowchart showing a second glow control process executed by the ECU of FIG.

FIG. 4 is a flowchart showing an abnormality detection process executed by the ECU of FIG.

FIG. 5 is a time chart explaining the operation of the engine control system of the first embodiment.

6 is an explanatory diagram illustrating how an abnormality is detected by the abnormality detection process of FIG.

FIG. 7 is a schematic configuration diagram showing an overall configuration of an engine control system of a second embodiment.

FIG. 8 is a flowchart showing a first glow control process executed by the ECU of FIG.

9 is a flowchart showing a second glow control process executed by the ECU of FIG.

10 is a flowchart showing an abnormality detection process executed by the ECU of FIG.

FIG. 11 is a time chart explaining the operation of the engine control system of the second embodiment.

[Explanation of symbols]

1 ... Battery 3 ... Electronic control unit (ECU) 5 ...
Power relay 7 ... Glow plug 9 ... Glow relay 11 ... Key switch IG ... Ignition position (ignition switch) ST ... Start position (starter switch) 13 ... Starter motor 15 ... Starter relay 17 ... Warning lamp 21 ...
CPU 23 ... Power supply circuit 25 ... Input buffer 27 ... A /
D conversion circuit (ADC) 29 ... Output circuit

Claims (5)

[Claims] 1. An electric power is supplied to a glow plug provided in an internal combustion engine by receiving electric power from a battery mounted on a vehicle.
In a glow plug energization control device for controlling non-energization, a first voltage detecting unit for detecting a battery voltage when energizing the glow plug, and a non-energizing device for energizing the glow plug Second voltage detecting means for detecting the battery voltage, and whether the difference between the voltage value detected by the second voltage detecting means and the voltage value detected by the first voltage detecting means is less than a predetermined value An energization control device for a glow plug, comprising: an abnormality detection unit that determines whether or not the difference is less than the predetermined value and determines that an abnormality has occurred. 2. The glow plug energization control device according to claim 1, further comprising pre-starting energization means for energizing the glow plug for a predetermined time when an ignition switch of the vehicle is turned on. The first voltage detection means detects the battery voltage at a predetermined timing within the predetermined time, and the second voltage detection means detects that the pre-starting energization means has stopped energizing the glow plug. Detecting the battery voltage at a predetermined timing of 1. The glow plug energization control device. 3. The glow plug energization control device according to claim 2, wherein it is detected whether or not a starter switch of the vehicle is turned on, and it is determined that the starter switch is turned on,
The starter motor for starting the internal combustion engine is energized, and at least the start control means for energizing the glow plug during energization of the starter motor is provided. When the glow plug is de-energized and the second voltage detection unit detects the battery voltage, the start control permission unit that permits the operation of the start control unit, and the first voltage detection unit. When the battery voltage is detected, detection of whether or not the starter switch is turned on is started, and the starter switch is turned on until the predetermined time elapses after the ignition switch is turned on. When this is detected, the energization to the glow plug by the pre-starting energization unit is forcibly stopped to detect the second voltage. The glow plug electrification control apparatus, characterized by comprising a detection control means for detecting a battery voltage in stages, a. 4. The glow plug energization control device according to claim 1, wherein the battery voltage may fluctuate due to a factor other than energization / de-energization of the glow plug. An energization control of a glow plug, comprising: a situation determining means for determining whether or not the abnormality determination inhibiting means inhibits the operation of the abnormality detecting means when the situation determining means makes a positive determination. apparatus. 5. The glow plug energization control device according to any one of claims 1 to 4, wherein when the abnormality detecting unit determines that an abnormality has occurred, the abnormality occurrence is detected by a vehicle occupant. An energization control device for a glow plug, comprising: a notifying unit for notifying the glow plug.