JPH0739863B2 - Heater glow plug controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glow plug control device for a vehicle heater provided in an intake pipe of an internal combustion engine.

(Prior Art) Conventionally, a heating device for a vehicle guides cooling water heated by an internal combustion engine as a heat source to a heater core, and blows air by a blower to blow warm air into a vehicle compartment for heating. However, in this type of heating device, warm air is not blown until the heating of the internal combustion engine is finished and the temperature of the cooling water rises to a temperature that can be used as a heating heat source. There were problems such as wearing.
Therefore, in addition to the heating device using cooling water as a heat source, a combustor and a heat exchanger are provided in the middle of the intake pipe of the internal combustion engine, and the heat generated by burning the fuel in the combustor is generated by the heat exchanger. A proposal was made for a heating system for automobiles that collects and blows air into the passenger compartment.
It is shown in Japanese Patent Application No. 59-106869.

(Problems to be Solved by the Invention) According to the above-described proposal of the automobile heating system, the combustor is provided with the vaporization glow plug for vaporizing the fuel and the ignition glow plug for igniting the vaporized fuel, and the internal combustion engine At the same time as the start of, the hot air for heating is obtained.

However, in the above-mentioned proposal, each of the vaporization glow plug and the ignition glow plug requires a control circuit such as a bridge circuit and a comparator for setting and controlling at a predetermined temperature, and has a complicated circuit configuration.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to simplify the configuration of a control device that holds the heat generation temperatures of the vaporization glow plug and the ignition glow plug at their respective predetermined temperatures. To provide a glow plug control device for a heater.

(Means for Solving the Problems) According to the present invention, in a heater having a combustor including a vaporization glow plug that vaporizes fuel and an ignition glow plug that ignites the vaporized fuel, each glow plug is positive. A resistance wire having a temperature coefficient of 1), one temperature-measuring resistor is provided for the two glow plugs, and the two glow plugs are provided for the one temperature-measuring resistor. Alternately connecting switching means is provided, and the switching means detects the terminal voltage of the temperature measuring resistor and detects the terminal voltage of the temperature measuring resistor, and the temperature measuring resistor corresponding to a predetermined heat generation temperature of each of the two glow plugs. When the terminal voltage is reached, the corresponding glow plug and the temperature measuring resistor are disconnected from each other, and the other glow plug and the temperature measuring resistor are connected to each other. Glow plug control device is provided It

Further, according to the present invention, there is also provided a glow plug control device for a heater, in which a resistor is connected in series to each glow plug to make the characteristics of the glow plug uniform.

(Operation) According to the present invention, one temperature measuring series resistor for detecting the heat generation temperatures of the two types of glow plugs is used, and the circuit is alternately switched by the switching means, so that the current of each glow plug is measured by the temperature measuring series resistor. Since the resistor is flown and the temperature is controlled according to the terminal voltage of the resistor, there is an effect that one detecting means can sufficiently control the temperature of the two types of glow plugs.

(Example) Next, the Example of this invention is described in detail using drawing.

FIG. 1 is a circuit configuration diagram of an embodiment of a glow plug control device for a heater according to the present invention, and FIG. 2 is a cross-sectional view showing an example of a combustor, and a heater configuration block showing related parts thereof. It is a figure. In FIG. 2, the combustor 1 has a cylindrical outer shape, and a hollow cylindrical ignition chamber 11 and a combustion chamber 12 made of a heat-resistant material are provided inside the combustor 1 with a partition wall 13 therebetween.
The vaporizer 21 having the vaporized glow plug 2 for vaporizing the fuel and the ignition glow plug 3 for igniting the vaporized fuel penetrate through the outer wall of the combustor 1 so that their respective tip portions reach the central portion of the ignition chamber 11. Is provided. The vaporizer 21 has its outer wall exposed to the inside of the combustion chamber 12 to receive the heat of combustion, and therefore is provided so as to be inclined from the outside of the combustor 1,
Further, the tip portion is projected through the partition wall to the ignition chamber 11.

The fuel supplied from the fuel supply port 22 of the vaporization device 21 becomes vaporized fuel by the heat generation of the vaporized glow plug 2 which is energized, and blows into the ignition chamber 11. On the other hand, the air introduced from the air intake 41 of the air cleaner 4 is guided to the ignition chamber 11, mixes with the vaporized fuel to generate a combustible mixture, and is ignited by the heat generation of the energized glow glow plug 3, Produces a flame. Then, it flows into the combustion chamber 12 through the passage provided in the partition wall 13, mixes with fresh air from the air passage 14 of the combustion chamber 12, becomes high-temperature combustion gas in the combustion chamber 12, and exits from the combustion chamber.
It flows into the heat exchanger 5 downstream from 15.

In the heat exchanger 5, the air taken in from the air intake 51 exchanges heat with the high-temperature combustion gas to become warm air, and is blown by the blower 52 to become warm air for heating into the passenger compartment. It is configured.

The combustion gas after heat exchange in the heat exchanger 5 is the intake pipe 61.
It is guided to the internal combustion engine 6 via the and is used when the internal combustion engine 6 is started or when it is supercooled.

Next, in FIG. 1, reference numeral 1a is a resistance wire having a positive temperature coefficient which serves as a heating element of the vaporization glow plug 2. From the battery 8, a main relay 8a, a temperature measuring series resistor 7a,
The resistance wire 2a is energized via the relay 2b. The temperature measuring series resistor 7a is a resistor having a small resistance value, the power limiting resistor 2c has a large resistance value, and the limited power is supplied to the low resistance wire 2a even when the relay 2b is off. It maintains the exothermic temperature.

Reference numeral 3a is a resistance wire having a positive temperature coefficient which serves as a heating element of the ignition glow plug 3, and from the battery 8 through a main relay 8a, a temperature measuring series resistor 7a, a relay 3b, and an adjusting resistor 3d. The resistance wire 3a is energized, and the limited power is supplied through the power limiting resistor 3c even when the relay 3b is off.

The adjusting resistor 3d is different in the vaporization glow plug 2 and the ignition glow plug 3 from each other in resistance value, temperature resistance characteristic, ultimate heat generation temperature, etc. It is used. Therefore, a resistor having a predetermined resistance value may be inserted and used as an adjustment resistor in the circuit of the resistance wire 2a of the vaporization glow plug 2.

Both the resistance wire 2a of the vaporization glow plug 2 and the resistance wire 3a of the ignition glow plug 3 have low resistance values when the resistance wires 2a and 3a are at a low temperature at the beginning of energization, and the temperature rises and Since the resistance value of
By switching 2b and 3b and measuring the terminal voltage of the temperature measuring series resistor 7a, the heat generation temperatures of the vaporization glow plug 2 and the ignition glow plug 3 can be detected.

Reference numeral 7 is a controller, which is connected to measure the terminal voltage of the temperature measuring series resistor 7a, detects the heat generation temperatures of both glow plugs 2 and 3, and also detects the main relay 8a and relays 2b and 3
It controls b respectively.

Next, the present embodiment configured as described above will be described with reference to the timing chart of FIG.

When the main relay 8a and the relays 2b and 3b are turned on and started at time A in FIG. 3 (a), both glow plugs are started.
When the resistance wires 2a and 3a are energized, their temperatures rapidly rise.

At time B after a predetermined time, the controller 7 relays
3b is turned off, the current supply to the resistance wire 3a is limited to the power limiting resistor 3c, and the supply from the temperature measuring series resistor 7a is cut off. By this operation, the temperature-measuring series resistor 7a becomes only the supply current related to the resistance wire 2a, and the terminal voltage of the temperature-measuring series resistor 7a becomes a predetermined heat generation temperature (for example, 500 degrees Celsius) of the vaporization glow plug 2 over time. When the predetermined terminal voltage is reached according to the predetermined resistance value of the resistance wire 2a corresponding to (before and after), the relay 2b is turned off and the relay 3b is turned on at the time C in the figure. Therefore, the calorific value of the vaporization glow plug 2 is only the calorific value generated from the limited electric power due to the current passing through the power limiting resistor 2c, and the above-mentioned predetermined exothermic temperature is exceeded due to the vaporization heat for vaporizing the fuel. It will never rise. In addition, since the relay 3b is turned on at the time of C,
The resistance wire 3a of the ignition glow plug 3 is connected to the temperature measuring series resistor 7a.
The terminal voltage of the temperature measuring series resistor 7a becomes only the current related to
When the predetermined terminal voltage is reached according to the predetermined resistance value of the resistance wire 3a corresponding to (about 10 degrees)
Turn off and turn on relay 2b. Then, this time, as in the case of the above point B, a series resistor for temperature measurement is used.
The heat generation temperature of the vaporization glow plug 2 is detected by the terminal voltage of 7a.

As described above, the relay 2b and the relay 3b are alternately switched to measure the terminal voltage of one temperature-measuring series resistor 7a, and thus two kinds of vaporization glow plugs 2 and ignition glow plugs 3 having different temperatures are used. The heat generation temperatures of and are controlled to be substantially constant.

On the other hand, immediately after the time point A, the fuel is supplied from the fuel supply port 22 of the vaporizer 21, touches the vaporized glow plug 2 that has reached a predetermined heat generation temperature to become vaporized fuel, and from the tip of the vaporizer 21. Eject into the ignition chamber 11.

Then, inside the ignition chamber 11, it mixes with the air introduced from the air cleaner to form a combustible mixture, and the ignition glow plug 3 that has reached a predetermined heat generation temperature is touched and ignited to generate a flame. Further, as described above, fresh air is introduced into the combustion chamber 12 to be supplied with fresh air and becomes high-temperature combustion gas, and this heat quantity is used for heating the passenger compartment through the heat exchanger 5.

FIG. 3 (b) is a timing chart when the vaporization glow plug 2 and the ignition glow plug 3 have been energized for a short time to reach their respective predetermined heat generation temperatures. One glow plug has a predetermined heat generation. After reaching the temperature, the relay related to this glow plug is turned off, and then a predetermined time (t) is set by a timer, after a lapse of t time, regulation is performed, and the relay related to the other glow plug is turned on. The timing chart is shown.

Moreover, the power limiting resistors 2c and 3c may not be used when the heat generation temperature rising characteristics of the vaporization glow plug 2 and the ignition glow plug 3 are sharply increased.

Although the present invention has been described with reference to the embodiment as described above, various modifications can be made within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effect of the Invention) As described in detail above, the present invention uses a single series resistor for temperature measurement to control the heat generation temperatures of two types of glow plugs, that is, a vaporization glow plug and an ignition glow plug. By switching the circuit of, the electric current of each glow plug is passed through the series resistor for temperature measurement, and it is controlled to a predetermined heat generation temperature according to the terminal voltage, so there is one or two means for temperature measurement. This makes it possible to control the temperature of the glow plug, save the temperature measuring step member, and improve the reliability of the entire glow plug control device.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of a glow plug control device for a heater according to the present invention, FIG. 2 is a sectional view showing an example of a combustor, and FIG. 3 is a timing chart of an example of the operation of the embodiment. It is a chart figure. 1 ... Combustor, 2 ... Vaporization glow plug, 3 ... Ignition glow plug, 5 ... Heat exchanger, 7 ... Controller, 8
...... Battery, 2b ...... Relay, 3b ...... Relay, 7a ...... Temperature measuring series resistor, 3d ...... Adjusting resistor.

Claims (2)

[Claims] 1. A heater having a combustor having a vaporization glow plug for vaporizing fuel and an ignition glow plug for igniting vaporized fuel, each glow plug having a resistance wire having a positive temperature coefficient. A temperature measuring resistor is provided for the two glow plugs, and switching means is provided for alternately connecting the two glow plugs in series to the one temperature measuring resistor, The switching means detects the terminal voltage of the temperature-measuring resistor, and when the terminal voltage of the temperature-measuring resistor corresponding to a predetermined heat generation temperature of each of the two glow plugs is reached, the glow plug is applicable. And the temperature measuring resistor are disconnected, and the other glow plug and the temperature measuring resistor are connected to each other. 2. The glow plug control device for a heater according to claim 1, wherein a resistor for equalizing the characteristics of the glow plug is connected in series to each glow plug.