JP4570590B2 - Engine glow plug energization control device - Google Patents

Description

  The present invention relates to a glow plug control technique for assisting engine starting.

2. Description of the Related Art Conventionally, a compression ignition type internal combustion engine represented by a diesel engine (hereinafter simply referred to as “engine”) has been known that includes a glow plug disposed in a combustion chamber. Some include a sensor that detects the temperature of engine cooling water as an outside air temperature, and an energization control device that controls the energization time or the energization amount of the glow plug according to the detected water temperature. This energization control device energizes the glow plug as necessary when starting the engine to generate heat, and further controls the energization time or energization amount, thereby igniting and burning the fuel spray. Is promoted and the current-carrying efficiency at that time is optimized. (For example, see Patent Document 1)
JP 2001-263216 A

  However, there is a case where power is supplied to a plurality of engines from one power source (battery). For example, when a working machine (refrigerator) or the like is mounted on a traveling vehicle (truck), the truck and the refrigerator each include a driving engine for traveling or working and a generator driven by the engine. . When one engine is driven at low temperature or when the other engine is started, the power from the generator provided in one engine charges the battery and the glow plug provided in the other engine. Is also supplied. In this case, the supply voltage to the glow plug becomes higher than the rated voltage. For this reason, if the glow plug is energized according to the outside air (cooling water) temperature, the temperature of the glow plug may rise too much and the coil may melt. Therefore, the problem to be solved by the present invention is to provide a glow plug energization control device that controls the glow plug to an optimum temperature and improves durability.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

The present invention includes a glow plug, a glow plug terminal voltage detecting means for detecting a glow plug terminal voltage, an outside air or cooling water temperature detecting means for detecting outside air or cooling water temperature, and a control means for connecting them. A glow plug energization control device for an engine, wherein an energization time to the glow plug is controlled according to a detection value detected by the glow plug terminal voltage detection means, and the control means detects the glow plug terminal voltage detection Based on the detection value detected by the means, it is determined whether the power is supplied from the battery alone or from the generator, and the energization time to the glow plug is switched to a preset time according to each supply voltage It is.

According to a second aspect of the present invention , in the glow plug energization control device for an engine according to the first aspect, the energization time to the glow plug is determined when the detected value detected by the glow plug terminal voltage detecting means is equal to or greater than a voltage set value. Is set to be shorter than the case of less than the set value.

According to a third aspect of the present invention , in the glow plug energization control device for an engine according to the first aspect, the control means sets the energization time to the glow plug in accordance with the detected value detected by the outside air or cooling water temperature detecting means. The configuration is such that the change is made within a preset set time.

According to a fourth aspect of the present invention , in the glow plug energization control device for an engine according to any one of the first to third aspects, the energization time of the glow plug is determined by a temperature detected by a temperature detection means. When the value is greater than or equal to the value, the fixed time is set regardless of the detection value detected by the glow plug terminal voltage detection means.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, even when one engine is in a driving state and a voltage higher than a rating is supplied such that power is supplied from the generator of one engine when the other engine is started. In addition, the temperature of the glow plug can be controlled to an optimum temperature, the engine start time can be shortened, and the durability of the glow plug can be improved. Furthermore, by improving the startability of the engine and the durability of the glow plug, the load on the starter can be reduced and the durability can be improved.

Further , the temperature of the glow plug can be controlled to an optimum temperature. Further, when power is supplied from the generator to the glow plug, the coil does not run out.

According to the second aspect, the temperature of the glow plug can be controlled to an optimum temperature. Furthermore, since the energization time to the glow plug is changed according to the supply voltage, useless power consumption can be eliminated.

According to the third aspect, the temperature of the glow plug can be controlled to an optimum temperature according to the temperature detected by the temperature detecting means. Further, the engine can be easily started even when the outside air temperature (cooling water temperature) is low.

According to the fourth aspect, the temperature of the glow plug can be controlled to an optimum temperature. Furthermore, the engine can be reliably started under any temperature environment.

  Next, embodiments of the invention will be described.

  FIG. 1 is a diagram showing a schematic configuration of a glow plug control device according to an embodiment of the present invention. 2 is a graph showing the temperature characteristics of the glow plug coil, FIG. 3 is a flowchart showing the glow plug energization control process, and FIG. 4 shows the relationship between energization time and temperature during the glow plug control shown in FIG. FIG. FIG. 5 is a flowchart showing a glow plug energization control process according to another embodiment. FIG. 6 is a graph showing the relationship between energization time and temperature during glow plug control according to another embodiment shown in FIG.

  A glow plug control device according to the present invention will be described with reference to FIG. First, electric power is supplied from a single power source (battery) 6 to a plurality (two in this embodiment) of engines 3 and 30. One of the engines 3 and 30 is for driving, and the other is for driving a working machine, for example, a refrigerator. The engines 3 and 30 are provided with generators 13 and 33, respectively. However, the engine is a diesel engine as an internal combustion engine, and the rated horsepower of the engines 3 and 30 and the power generation capacity of the generators 13 and 33 may be the same or different.

  Since the engines 3 and 30 have substantially the same configuration, only one engine 3 will be described. A key switch 14 is connected to the battery 6, each electrical component is connected to the “ON” position, and a glow plug drive circuit 7 and a cell motor drive circuit 10 are connected to the “START” position. The plug 4 and the cell motor 15 are connected. The voltage supplied to the drive circuit is detected by a voltage sensor 12 serving as detection means. However, the voltage sensor 12 may be connected to the input side of the glow plug 4. The drive circuits 7 and 10 and the voltage sensor 12 are connected to an electronic control unit (hereinafter referred to as “ECU”) 2 serving as control means. The ECU 2 controls the rotational speed of the engine 3 and the like.

  The glow plug 4 generates heat under the control described later, and is provided facing a combustion chamber (none of which is shown) of each cylinder of the engine 3. When the engine is started, electric power from the battery 6 is supplied to the drive circuit 10. The combustion chamber is supplied by heating the combustion chamber, and the fuel injected from an injector (not shown) is heated in the interior thereof, thereby promoting the ignition and combustion of the fuel. The starter of the engine 3 includes a pinion gear, a magnet switch, a starter motor (not shown), and the like. When the engine is started, the cell motor 15 is turned on or after the glow plug 4 is energized by the power from the battery 6. The ring gear (not shown) connected to the crankshaft meshing with the pinion gear is driven to rotate by operating and rotating the pinion gear.

  A generator 13 is connected to the output shaft (crankshaft) of the engine 3, and power is generated by rotating the crankshaft when the engine 3 is started. The generator 13 is connected to the battery 6 and charges the battery 6 when the engine is operating.

The ECU 2 is also supplied with electric power from the battery 6, and the ECU 2 has a glow lamp , a glow plug drive circuit 7, a cell motor drive circuit 10, a water temperature sensor 11, and a voltage sensor 12 for detecting a glow plug supply voltage. It is connected. The water temperature sensor 11 is disposed on a radiator or the like. Thus, the voltage sensor 12 (glow voltage detection means) detects the glow voltage VP, and the water temperature sensor 11 detects the engine coolant temperature TW, which is the temperature of the coolant circulating in the cylinder block of the engine 3. The detection signals are output to the ECU 2 respectively. However, although the temperature of the cooling water is detected in order to detect the temperature of the engine, it may be configured to detect the outside air temperature.

This glow lamp is turned on when the glow plug 4 is operated, and is controlled by the ECU 2 to be in one of the on and off states.

The ECU 2 includes energization stop control means, timing means, determination means, etc., and is composed of a microcomputer comprising a CPU, RAM, ROM, I / O interface, etc., and operates with the battery 6 as a power source. The detection signals of the various sensors 11 and 12 described above are input to the CPU after A / D conversion, amplification, and the like are performed by the I / O interface. The CPU controls the glow plug 4, the cell motor 15, the glow lamp, and the like according to these input signals when starting the engine. For example, when the glow plug 4 is in operation, the glow lamp is turned on, and control is performed to notify the driver of the operation of the glow plug 4 or when the key switch 14 is set to the START position, the cell motor 15 is rotated and fuel is injected. Thus, the engine 3 can be controlled to start.

  FIG. 2 shows the temperature rise characteristic of the glow plug 4 with respect to the coil energization time t of the coil temperature TC. That is, when the glow plug is energized with the first voltage V1 (for example, 12V) of the battery 6 alone and when the glow plug is energized with the second voltage V2 (for example, 15V) from the battery 6 and the generator 13 (V1 < The time change of the coil temperature TC of V2) is shown. Furthermore, the allowable temperature of the coil of the glow plug 4 used in the present embodiment is Ta, and the time for reaching the allowable temperature Ta is shown. The time to reach the allowable temperature Ta when using V1 is t1 (for example, 15 seconds), and the time to reach the allowable temperature Ta when using V2 is t2 (for example, 10 seconds) (t1> t2). When the power is supplied, the temperature reaches the permissible temperature in a short time, and if the energization is continued, the permissible temperature is far exceeded, so that the glow plug is damaged quickly and the life is shortened. When power is supplied by the battery 6 alone, the time to reach the allowable temperature is longer than the above, but even if it is energized for a long time, it does not rise so high that it is damaged.

  Further, the control by the ECU 2 of the glow plug 4 at the time of starting the engine will be described using the flowchart of FIG. First, the ECU 2 determines whether or not the detection value detected by the water temperature sensor 11, that is, the water temperature TW is lower than a first set temperature T1 (for example, 10 ° C.) (S310). When the ECU 2 determines that the water temperature TW is lower than the first set temperature T1 (S310: YES), the voltage (hereinafter referred to as “glow voltage”) VP supplied to the glow plug is the third set voltage V3 (for example, 13.5 V). It is discriminated whether it is less than (S320). The third set voltage V3 is an intermediate voltage between the first voltage and the second voltage (V1 <V3 <V2). When it is determined that the glow voltage VP is less than the third set voltage V3 (S320: YES), since the voltage is supplied only by the battery 6, the energization time t to the glow plug 4 is set to the first set time t1. (S330). On the other hand, when it is determined that the glow voltage VP is equal to or higher than the third set voltage V3 (S320: NO), power is supplied from the generator 13 that supplies a voltage higher than that of the battery. The energization time t is set as the second set time t2 (S340). On the other hand, when it is determined that the water temperature TW is equal to or higher than the set temperature T1 (S310: NO), the energization time to the glow plug 4 is set to a third set time t3 (for example, 5 seconds) shorter than the second set time t2. (T1> t2> t3) (S350).

  FIG. 4 is a graph showing the relationship between energization time and temperature during glow plug control. That is, the X axis represents the water temperature TW detected by the water temperature sensor 11, and the Y axis represents the glow energization time t.

  Next, the control of the glow plug 4 by the ECU 2 when the engine is started according to another embodiment of the control process of the glow plug 4 will be described with reference to the flowchart of FIG. In the case of this embodiment, the energization time is controlled even when the water temperature (outside air temperature) becomes equal to or lower than the second set temperature T2 (for example, −20 ° C.) lower than the first set temperature T1 (for example, 10 ° C.). To do. That is, FIG. 6 is a graph showing the relationship between energization time and temperature during glow plug control, and the water temperature TW detected by the water temperature sensor 11 is between the first set temperature T1 and the second set temperature T2. The energization time for the glow plug 4 is longer as the temperature is lower and shorter as the temperature is higher than the set time. When the supply voltage is high, the energization time is longer as the temperature is lower and the energization time is shorter as the temperature is lower, within a shorter set time than the above.

  More specifically, first, it is determined whether or not the detected value detected by the water temperature sensor 11, that is, the water temperature TW is lower than the set temperature T1 (S510). When it is determined that the water temperature TW is lower than the set temperature T1 (S510: YES), it is determined whether the water temperature is lower than the second set temperature T2 (S520). When the water temperature is lower than the second set temperature T2 (S520: YES), the energization time t to the glow plug 4 is set as the first set time t1 (S540). When the water temperature is equal to or higher than the second set temperature T2 (S520: NO), it is determined whether the glow voltage VP is lower than the third set voltage V3 (S530). When it is determined that the glow voltage VP is less than the third set voltage V3 (S530: YES), the energization time t to the glow plug 4 is obtained from the map (or calculation) shown in FIG. 6 according to the value of the water temperature TW. Is set to a time between t1 and t3 (S550). When it is determined that the glow voltage VP is equal to or higher than the third set voltage V3 (S530: NO), the energization time t to the glow plug 4 is a map shown in FIG. 6 according to the value of the water temperature TW ( Or a time between t2 and t3 obtained by calculation). (S560). If it is determined that the water temperature TW is equal to or higher than the first set temperature T1 (S510: NO), the energization time to the glow plug 4 is set to the third set time t3 (S570).

  As described above, an engine including a glow plug, a glow plug terminal voltage detecting means for detecting a glow plug terminal voltage, an outside air or cooling water temperature detecting means for detecting outside air or cooling water temperature, and a control means for connecting them. In the glow plug energization control apparatus, the energization time to the glow plug is controlled in accordance with the detected value detected by the glow plug terminal voltage detecting means, so that the temperature of the glow plug can be optimally controlled. In addition, the durability of the glow plug can be improved, and the startability of the engine can be improved. Furthermore, the load on the starter is reduced by these, leading to an improvement in durability.

  Further, it is determined whether the electric power is supplied from the battery alone or from the generator based on the detection value detected by the glow plug terminal voltage detecting means, and the energization time to the glow plug is set in advance according to each supply voltage. Because it is configured to switch to the set time, the energization time is controlled by the supply voltage to the glow plug, the glow plug coil can be prevented from being melted by the amount of power supplied, and the durability of the glow plug is improved. Can do.

  In addition, the energization time to the glow plug is set to be shorter when the detection value detected by the glow plug terminal voltage detection means is equal to or higher than the voltage setting value, as compared with the case where it is less than the setting value. Since the energization time to the glow plug is changed in accordance with this, wasteful power consumption can be suppressed.

  In addition, since the energization time to the glow plug is changed within a preset time according to the detection value detected by the outside air or cooling water temperature detecting means, the engine can be easily operated even when the outside air temperature is low. Can be started.

  Also, if the detected value detected by the outside air or cooling water temperature detecting means is equal to or higher than the temperature set value, it is set at a constant time regardless of the detected value detected by the glow plug terminal voltage detecting means. The engine can be reliably started even in a temperature environment, and power consumption can be suppressed.

The figure which shows schematic structure of the control apparatus of the glow plug which concerns on one Example of this invention. The graph which shows the temperature characteristic of the coil of a glow plug. The flowchart figure which shows a glow plug energization control process. The graph which shows the relationship between the electricity supply time at the time of glow plug control, and temperature. The flowchart figure which shows the glow plug energization control processing of another Example. The graph which shows the relationship between the electricity supply time at the time of glow plug control of another Example, and temperature.

2 ECU
3 Engine 4 Glow Plug 6 Battery 7 Drive Circuit 8 Glow Lamp 11 Water Temperature Sensor 12 Voltage Sensor 13 Generator 14 Key Switch 15 Cell Motor

Claims (4)

Glow plug energization control for an engine comprising a glow plug, a glow plug terminal voltage detecting means for detecting a glow plug terminal voltage, an outside air or cooling water temperature detecting means for detecting outside air or cooling water temperature, and a control means for connecting them. The apparatus controls an energization time to the glow plug according to a detection value detected by the glow plug terminal voltage detection means, and the control means detects the detection detected by the glow plug terminal voltage detection means. It is determined whether the power is supplied from a battery alone or from a generator based on the value, and the energization time to the glow plug is switched to a preset time according to each supply voltage . Glow plug energization control device. 2. The glow plug energization control device for an engine according to claim 1, wherein the energization time to the glow plug is less than a set value when a detected value detected by the glow plug terminal voltage detecting means is equal to or greater than a voltage set value. An engine glow plug energization control device, characterized in that it is set to be shorter than in the case of . 2. The glow plug energization control device for an engine according to claim 1, wherein the control unit is configured to set an energization time to the glow plug within a preset time in accordance with a detection value detected by the outside air or cooling water temperature detection unit. The glow plug energization control device for an engine, characterized in that the configuration is changed by the above . The glow plug energization control device for an engine according to any one of claims 1 to 3, wherein the glow plug energization time is determined when the detected value detected by the temperature detecting means is equal to or higher than a temperature set value. A glow plug energization control device for an engine, characterized in that the constant time is set regardless of the detection value detected by the plug terminal voltage detection means .

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