JP3184198B2 - Oil burner control circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a vaporized oil combustor provided with a vaporizing heater.

2. Description of the Related Art FIG. 4 shows a schematic system diagram of a conventional oil burner.

In the figure, 1 is a heat exchanger, 2 is a burner for heating the heat exchanger 1, 3 is a vaporizing section for sending vaporized kerosene to the burner 2, 4 is a vaporizing heater built in the vaporizing section, 5 is a temperature of the vaporizing section. 6 is a pulse pump for sending kerosene to the vaporizing section 3, and 7 is a burner 2 for supplying combustion air to the vaporizing section 3.
Is a controller for controlling these loads.

Next, a block diagram of the controller 8 of the oil combustor is shown in FIG.

In the figure, 9 is an operation switch, 10 is an input circuit for inputting an operation switch, and 11 is a combustion control circuit for receiving the signal from the input circuit 10 and controlling the combustion of the burner 2. The blower motor 7 and the pulse pump 6, The heater 4 is controlled. Reference numeral 12 denotes an input circuit of the vaporization section thermistor 5, and reference numeral 13 denotes a disconnection determination timer circuit of the vaporization section thermistor 5, both of which are connected to the disconnection detection circuit 14 to abnormally stop the vaporization heater 4.

With this configuration, when the operation switch 9 is first turned on,
The signal is taken into the input circuit 10, the heater 4 is turned on via the combustion control circuit 11, and the preheating of the vaporizing section is started.
At the same time, the disconnection determination timer 13 is driven. When the timer is up, the signal of the thermistor 5 is taken into the disconnection detection circuit 14 via the input circuit 12 and is determined. If there is a disconnection abnormality, the heater 4 is turned off. afterwards,
When the operation switch is operated again, the operation returns from the abnormal state, the heater 4 is turned on again, and the operation of starting the disconnection determination timer 13 is repeated.

Here, the reason for the need for the disconnection determination timer is that the temperature of the vaporizing section is generally controlled to about 250 ° C, so that a high-temperature thermistor is usually used for the sensor, and therefore the normal temperature state at the start of preheating In this case, the resistance value of the thermistor is high and cannot be distinguished from the disconnection state. Therefore, it is necessary to make a determination after energizing the heater for a certain period of time to increase the temperature of the vaporizing section.

However, in the above configuration, even if the disconnection is detected once and the heater 4 is turned off, if the operation switch is operated immediately thereafter, the heater 4 is turned on again and the disconnection is performed. Power is supplied during the determination timer.

Further, if this operation is repeated, there is a problem that the current is repeatedly applied without cooling the vaporized portion, and eventually the device is destroyed due to an abnormal temperature rise.

The present invention solves such a conventional problem, and provides a safe control in which the temperature of the vaporizing section does not abnormally increase even if the operation of resetting the repeated disconnection abnormality is performed as described above. The purpose is to do.

Means for Solving the Problems In order to solve the above problems, a control circuit for an oil combustor according to the present invention includes a vaporizing section having a built-in oil vaporization heater, a combustion section for burning the vaporized oil, and the vaporizing section. A temperature sensor such as a thermistor for detecting the temperature of the heater, a drive unit for controlling the energization / stop of the vaporization heater based on the signal, and a disconnection for detecting the disconnection of the temperature sensor and stopping the energization of the vaporization heater. A detection unit, a delay timer for delaying the disconnection determination by a predetermined time from the start of energization of the vaporizing heater, a forced timer for performing a specific forced operation different from the normal operation after the disconnection is detected, and a forced air blowing circuit. While the re-energization of the vaporization heater is forcibly stopped, the blower is driven through a forced blower circuit, and reception of a return operation including at least an operation switch operation is prohibited. Configuration.

Operation In the present invention, once the disconnection is detected by the above configuration, the forced timer starts, and during this time, the air is blown by the blowing means, so that the vaporizing section is cooled. Since this operation is forcibly performed, the operation is not reset by the user's switch operation in the middle of the forcible timer, and the heater energization does not start again. Therefore, the cooling time of the vaporizing unit can be always ensured. . Therefore, it is possible to prevent an abnormal temperature rise in the vaporizing section.

Embodiment Hereinafter, a control circuit of an oil combustor according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram of a control circuit of an oil-burning machine according to one embodiment of the present invention. 2.) Combustion control circuit (drive unit) for controlling combustion in (2)
Then, the blower motor 7 and the pulse pump 6, the vaporizing heater 4
Control. Reference numeral 12 denotes a disconnection determination timer (delay timer) circuit of the vaporizing section thermistor (temperature sensor) 5, both of which are connected to the disconnection detection circuit 14. The disconnection detecting circuit 14 is connected to a forced timer 15, through which the heater 4 is connected to the blower motor 7 via a forced blower circuit 16.
It is connected to the.

FIG. 2 is a time chart showing a temperature change of the vaporizing section when the embodiment is normal, and FIG. 3 is a time chart when a disconnection is detected in the embodiment. The operation of the above configuration will be described. When the operation switch 9 is turned on, it is taken into the operation input circuit 10 and sent to the combustion control circuit 11, where the vaporizing heater 4 is first turned on, and preheating is started. At the same time, the disconnection determination timer 13 also starts. Then, as shown in FIG. 2, the temperature of the vaporizing section starts to rise, and usually, within the timer time (T1: for example, 150
Seconds), the temperature reaches the disconnection judgment temperature (td: 150 ° C, for example).
The signal from the vaporizing section thermistor 5 is input to the combustion control circuit 11 via the thermistor input circuit 12 and thereafter the heater 4
Repeats ON / OFF, and the vaporizing section 3 is controlled to a constant temperature. When hot water is supplied at this point, the combustion control circuit 11 drives the blower motor 7 and the pulse pump 6 to start combustion.

Next, the operation when the vaporizing section thermistor 5 is disconnected will be described.

Similarly, when the operation switch 9 is turned on, energization of the heater 4 and counting of the disconnection determination timer 13 are started. Then, as shown in FIG. 3, the temperature of the vaporizing section 3 rises. However, since the vaporizing section thermistor 5 is in a disconnected state, the resistance value remains high. Then, when the disconnection determination timer 13 (T1) is completed, the disconnection detection circuit 14 is driven and the temperature data of the vaporizing section thermistor 5 is taken in from the thermistor input circuit 12, and it is determined that the disconnection determination temperature (td: 150 ° C.) or less. Then, the compulsory timer 15 (t2: for example, 200 seconds) is driven. Then, during this time, the heater 4 is turned off.

Further, the forced air blowing circuit 16 is driven, and the air blowing motor 7 starts rotating. Then, as shown in FIG. 3, the temperature of the vaporizing section 3 decreases. During the forced timer 15, even if an operation for recovering from an abnormality (for example, operation of an operation switch) is performed, the operation is not accepted and forced air blowing is continued. Therefore, at the time when the compulsory timer 15 (T2) has expired, even if the recovery from the abnormality has occurred, at this time the vaporizing section 3 is sufficiently cooled,
During the next disconnection determination timer 13 (T1), the temperature of the vaporizing section 3 does not abnormally rise.

As described above, it is possible to realize a safe operation against disconnection of the vaporizing section thermistor 5 only by adding a simple circuit from the conventional example.

Effects of the Invention As described above, according to the control circuit of the oil combustor of the present invention, the following effects can be obtained.

(1) When the thermistor in the vaporization section is disconnected, the abnormal temperature rise of the vaporization section can be prevented, and the reset operation by the switch operation is prohibited during the forced timer, thus realizing a safe and highly reliable system. it can.

(2) The configuration is simple and can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control circuit of an oil combustor according to an embodiment of the present invention, FIGS. 2 and 3 are characteristic diagrams showing a temperature change of a vaporizing section of the embodiment, and FIG. FIG. 5 is a schematic block diagram of a combustor, and FIG. 5 is a control circuit block diagram of the conventional example. 2 ... burner (combustion unit), 3 ... vaporization unit, 4 ... vaporization heater, 5 ... vaporization unit thermistor (temperature sensor), 11 ...
... combustion control circuit (drive unit), 13 ... disconnection determination timer (delay timer), 14 ... disconnection detection unit, 15 ... forced timer.

Continuing on the front page (72) Inventor Masaatsu Inoue 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinji Miyauchi 1006 Kadoma, Kazuma, Kadoma, Osaka Pref. 72) Inventor Seiichi Shinoda 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-58-75622 (JP, A) JP-B-63-24217 (JP, B2) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) F23N 5/24 113

Claims (1)

(57) [Claims] 1. A vaporizing section having a built-in heater for vaporizing oil, a burning section for burning the vaporized oil, a temperature sensor such as a thermistor for detecting the temperature of the vaporizing section, and a signal from the heater for energizing / discharging the heater. A drive unit for controlling the stop, a disconnection detection unit for detecting disconnection of the temperature sensor and stopping the energization of the vaporization heater, a delay timer for delaying the disconnection determination for a predetermined time from the start of the vaporization heater energization, and disconnection detection A forced timer and a forced air circuit for performing a specific forced operation that takes a normal operation later are provided, and during the forced tie operation, re-energization of the vaporization heater is forcibly stopped, and the blowing means is driven through the forced air circulation. And a control circuit for the oil combustor configured to prohibit the return operation including at least the operation switch operation.