JP6933908B2 - Electric fryer safety device - Google Patents

Description

The present invention relates to a safety device for an electric fryer. Specifically, in an electric fryer, it is a safety device to notify that there is a risk of fire because the contacts of the magnetic contactor that supplies power are in a welded state even though the inside of the oil tank is abnormally high temperature. be.

A heater installed in the oil tank, a control unit that controls the entire device, an electromagnetic contactor that controls the energization of the heater by a command from the control unit, and an abnormally high temperature detector installed in the oil tank. In the electric fryer, a safety device for preventing a fire due to an abnormally high temperature in the tank has been conventionally adopted.
Normally, when the temperature sensor or high limit detects an abnormally high temperature, the signal circuit of the magnetic contactor is cut off and the main energization is cut off at the same time by using the output to the magnetic contactor of the control board and the contact of the high limit itself. A method has been adopted in which the alarm unit is operated to allow the user to turn off the power switch installed in front of the electric fryer.

However, the power switch of the electric fryer cuts off the electric power applied to the control board which is the control unit, and does not directly cut off the power flowing to the heater. Normally, it is thought that the power of the heater is cut off when the power switch is turned off, but even if the power switch of the electric fryer is turned off, the magnetic contactor itself will malfunction and the heater will not be energized unless the contacts are released. Not blocked.

Moreover, the power plug of the electric fryer cannot be pulled out because it is on the back of the electric fryer. Therefore, the power supply cannot be cut off unless the breaker of the distribution board is turned off. The only way to shut off the AC three-phase 200V power applied from the power supply to the heater is to shut off the switchboard breaker in the store where the electric fryer is installed.

Therefore, as shown in Patent Document 1, by providing a current transformer that detects the current flowing through the heater, the control device can grasp the energization state, and the energization control element drive signal is not output from the control device. Nevertheless, when the current flowing through the heater is detected, if the detected value is equal to or higher than a certain value, the control device determines that the energization control element has failed, and after operating the notification device for a certain period of time, A signal for driving a leakage breaker is output from a control device to stop the entire electric fryer.

The device of Patent Document 1 requires another detection circuit for reading the input current detected by the current transformer, and cannot meet the demand for effective use of the space of the electric fryer.

However, magnetic contactors that energize heaters in electric fryer are caused by contact life due to the number of times the magnetic contactor itself is opened and closed, contact sticking due to oil smoke intrusion, and contact welding due to overcurrent. Welding of contacts was not uncommon. In such a case, if the welding of the contacts of the magnetic contactor cannot be recognized, even if the power switch of the electric fryer is shut off, the energization of the heater is not cut off, which may lead to a fire. That is, if these contacts are welded, even if an abnormal overheat prevention device such as a high limit, which is a safety device, is activated, the contact of the magnetic contactor is not cut off, so the safety device installed in the electric fryer is meaningless. It will not be there.

Japanese Patent Application Laid-Open No. 11-32923

Therefore, in the present invention, as a safety device for an electric fryer, a relay that senses contact (ON) and cutoff (OFF) of a contact of an electromagnetic contactor and outputs the relay to a control unit that controls the entire electric fryer is provided , and the control unit provides a relay. , If an abnormally high temperature detection signal is received from the abnormally high temperature detector and it is detected that the relay contact of the relay is not interrupted even though the drive signal to the magnetic contactor is blocked, the electromagnetic contactor The purpose is to make sure that the heating of the electric fryer is stopped and the cause of the fire is reduced by issuing an alarm and making it possible to cancel the alarm only by turning off the breaker. do.

In order to solve the above problems, the first invention constitutes an electric fryer safety device as follows.
First, the electric fryer is arranged so as to be supplied with power from a breaker installed outside the electric fryer, and the electric fryer supplies power from a heating heater installed in an oil tank and the breaker. on a control unit, an electromagnetic contactor for controlling the energization to the driving signal thus from the breaker to the heater from the control unit, the supply operation of said driving signal by the control unit for controlling the entire device is supplied or a power switch to turn off, is installed in the oil vessel, that senses an abnormal high temperature having a and abnormally high temperature detector for output the abnormally high temperature detection signal to the control unit.
Second, the output side of the electromagnetic contactor of the electric fryer, the relay is provided with a relay contact in conjunction with the contact and blocking contact of the electromagnetic contactor, contacts or blocking of the relay contacts said control unit and the relay so as to input and said control unit Ru is connected to.
Third, the control unit receives the abnormally high temperature detection signal from the abnormally high temperature detection unit, wherein even though not emit a drive signal to the electromagnetic contactor, the relay contact of the relay is not interrupted upon detection, the electromagnetic contactor contact welding has recognized and the operating the alarm unit by a command to the, by continuing operation of the alarm unit by turning off the power switch, turning off the circuit breaker are to prevent release an alarm only, by cutting the breaker, thereby interrupting the power supply to the heater of the electric fryer, to release the alarm.

In the second invention, in the first invention, when the breaker is turned on again after the alarm is released by turning off the breaker, the control unit is energized without turning on the power switch. The control unit operates the alarm unit.

The third invention is the first or second aspect of the invention, the electromagnetic contactor has a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic installed in the heater side of the main magnetic contactor consists of a contactor, the relay, characterized in that provided on the output side of the main magnetic contactor.

The fourth invention is the first or second aspect of the invention, the electromagnetic contactor has a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic installed in the heater side of the main magnetic contactor consists of a contactor, the relay, characterized in that it comprises two relays provided on the output side of the output side and the heater electromagnetic contactor of the main electromagnetic contactor.

The fifth aspect of the invention, in the first or second aspect of the invention, the electromagnetic contactor has a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic installed in the heater side of the main magnetic contactor consists of a contactor, the relay, characterized in that provided on the output side of the heater electromagnetic contactor.

A sixth invention, in any one invention of the first to fifth, wherein the abnormally high temperature detector is a high limit switch having a plurality of contacts, one contact of the said plurality of contacts the disposed on the energizing circuit to the heater, abnormal when high temperature is detected, by blocking said contact, said regardless of whether one is aware of the welding of the contacts of the electromagnetic contactor, direct power of the heater it shall be the features of the cut.

According to the first invention, the control unit may receive the abnormally high temperature detection signal from the abnormally high temperature detector only, even though not emit a drive signal to the electromagnetic contactor, relay contacts of relay is not interrupted when it is detected that recognizes that there is welded to the contact of the electromagnetic contactor, Ru generate an alarm. As a result, it has become possible to effectively prevent a more dangerous fire caused by welding of the contacts of the magnetic contactor of the electric fryer.
In addition, since the relay itself can be used in a small size, the distribution space of the electric fryer can be effectively used, resulting in an electric fryer with a compact safety device.

Further , according to the first invention, when the alarm unit issues an alarm, the alarm can be canceled only by turning off the breaker installed outside the electric fryer . Therefore, the breaker is turned off to cancel the alarm. it is necessary, energization of the electric fryer itself pressurized thermal heaters also be cut off the power switch to be mounted on it was possible to solve the problem of there be reaching the fire without being interrupted.
Further, according to the second invention, if the breaker is turned on again after the alarm is released by turning off the breaker, the control unit is energized and the alarm is issued without turning on the power switch. , I was able to improve the safety.

Albeit the effect of the third invention, relay, by provided on the output side of the main magnetic contactor, it becomes especially can be reliably grasped contact welding of the main electromagnetic contactor.

There is the effect of the fourth invention, the relay is, by providing al to an output side of the output side and the heater electromagnetic contactor of the main magnetic contactor, the main magnetic contactor and any contact of the heater electromagnetic contactor We were able to grasp the welding and improve the safety.

Albeit the effect of the fifth invention, the relay is, by provided on the output side of the heater electromagnetic contactor, it becomes especially can be reliably grasped contact welding heater electromagnetic contactor.

Although it is an effect of the sixth invention, when an abnormally high temperature is detected, a means is added to cut off the contact of the high limit switch arranged on the energization circuit to the heater and turn off the power supply to the heater. so, a more safety can be a high-Mel.

Electrical circuit diagram of the first embodiment of the present invention Electrical circuit diagram of the second embodiment of the present invention Explanatory drawing which shows operation process of this invention

Hereinafter, embodiments for carrying out the present invention will be described together with examples.
The present invention relates to a safety device for a commercial electric fryer used to provide fried foods at restaurants, convenience stores, and the like.

The basic structure of the electric fryer used in the safety device shown in the embodiment is that an oil tank for storing a required amount of cooking oil is installed in the box, and a heating heater H for heating the cooking oil is installed in the oil tank. On the front side of the oil tank, there is an electrical component including a control section CB that controls the entire device, and an operation panel on which a power switch, a heating start switch, a menu setting switch, and the like are arranged is mounted on the surface of the electrical component. The operation panel is equipped with an alarm unit A that notifies an abnormality by a display and a buzzer sound.

Then, in the oil tank of the electric fryer used in the examples, a heating heater H for heating the cooking oil, a temperature sensor TH for controlling the set temperature of the cooking oil, and an abnormally high temperature of the cooking oil are detected. High limit HL is arranged. Both the high limit HL and the temperature sensor TH can be used for the abnormal high temperature detection in the present invention, but the high limit HL is used for the abnormal high temperature detection in the examples.

Hereinafter, the safety device for the electric fryer according to the first embodiment will be described with reference to FIGS. 1 and 3. FIG. 1 is an electric circuit diagram of an electric fryer provided with a safety device according to the first embodiment, and FIG. 3 is an explanatory diagram showing an operation process of the same embodiment.

The code RST shown at the top of FIG. 1 is a power source for a 200 V electric fryer of three-phase alternating current. The symbol ELB at the lower part in the figure of the power supply RST is a breaker, and the breaker ELB is arranged at a position away from the electric fryer in the facility where the electric fryer is installed. The power supply RST is connected to the electrical component of the electric fryer via the breaker ELB.

The electrical unit is equipped with electromagnetic contactors MC1 and MC2 that energize and shut off the heating heater H in the oil tank, and a control unit CB that controls the entire heating heater H including control of the electromagnetic contactors MC1 and MC2. ing. In this embodiment, two types of magnetic contactors, a main magnetic contactor MC1 and a heater magnetic contactor MC2, are used. However, even if the number of magnetic contactors in the present invention is one, a plurality of types other than the two types are used. It may be.

When the breaker ELB is ON as shown in FIGS. 3 (1) and 1, the main electromagnetic contactor MC1 and the control unit CB are energized from the power supply RST. At this point, since the drive signal is not output from the control unit CB, the contact S1 of the main magnetic contactor MC1 is cut off (OFF) as shown in FIG. Therefore, the current toward the heater H is cut off by the main electromagnetic contactor MC1.

There is a signal circuit C1 between the main magnetic contactor MC1 and the control unit CB, and the control unit CB outputs a drive signal to the main magnetic contactor MC1 through the signal circuit C1. The drive signal turns on the contact S1 of the main magnetic contactor MC1. As a result, the heater electromagnetic contactor MC2 is energized. To cut off the energization of the main magnetic contactor MC1, the signal circuit C1 is cut off (OFF) to cut off the output of the drive signal.

When the user starts using the electric fryer, the power switch on the front panel is turned on as shown in FIG. 3 (2). As a result, when the control unit CB operates and recognizes that there is no abnormality in the electric fryer itself, a drive signal is sent from the control unit CB to the main magnetic contactor MC1 as shown in FIG. 3 (3).

As a result, as shown in FIG. 3 (4), the contact S1 of the main magnetic contactor MC1 is turned on, and the heater magnetic contactor MC2 is energized. As shown in FIG. 1, a relay R is arranged outside the OUT side of the main magnetic contactor MC1. The relay R has a relay contact R1 that is interlocked with contact (ON) and cutoff (OFF) of the contact S1 of the main magnetic contactor MC1.

The relay R and the control unit CB are connected, and ON and OFF of the relay contact R1 are input to the control unit CB. Therefore, when the heater magnetic contactor MC2 is energized, the control unit CB detects the ON of the relay contact R1, that is, the ON of the contact S1 of the main magnetic contactor MC1, as shown in FIG. 3 (5).

The heater electromagnetic contactor MC2 is connected to the heating heater H and receives electricity from the main electromagnetic contactor MC1 to control the temperature of the heating heater H. The heater electromagnetic contactor MC2 has a contact S2 that energizes and shuts off the heater H. Before the heating start switch is operated, the contact S2 of the heater electromagnetic contactor MC2 is turned off as shown in FIG. 1, so that the heating heater H is not energized.

When starting cooking with the electric fryer, the heating start switch of the operation panel is turned on as shown in FIG. 3 (6). At this time, as shown in FIG. 3 (7), the control unit CB outputs a drive signal to the heater electromagnetic contactor MC2, whereby the contact S2 of the heater electromagnetic contactor MC2 is turned on, and FIG. 3 (8) shows. As shown, the heater electromagnetic contactor MC2 is turned on. The drive signal is output through a signal circuit C2 provided between the control unit CB and the heater electromagnetic contactor MC2. As a result, as shown in FIG. 3 (9), the cooking oil in the oil tank is heated by the heater H, and the fried food is cooked. In order to cut off the energization of the heater electromagnetic contactor MC2, the signal circuit C2 is cut off (OFF) to cut off the output of the drive signal.

A temperature sensor TH is installed in the oil tank to maintain the temperature of cooking oil suitable for fried foods. When the temperature of the cooking oil in the oil tank rises due to continuous heating of the heater H, the temperature sensor TH senses the set high temperature, and the control unit CB determines that the temperature is high, as shown in FIG. 3 (10). As in (11), the signal circuit C2 is cut off. As a result, the contact S2 of the heater electromagnetic contactor MC2 is turned off, and as shown in FIG. 3 (12), the energization of the heater electromagnetic contactor MC2 to the heating heater H is cut off.

When the energization OFF state of the heater H continues, the temperature of the cooking oil in the oil tank drops, the temperature sensor TH detects the set low temperature as shown in FIG. 3 (13), and the control unit CB becomes low temperature. Judgment is made, a drive signal is output to the heater electromagnetic contactor MC2 as shown in FIG. 3 (14), and the contact S2 of the heater electromagnetic contactor MC2 is turned on as shown in FIG. 3 (15). As a result, the heating heater H is energized again, and heating is restarted.

In this way, the fried food is cooked while the temperature is controlled by the heater electromagnetic contactor MC2. However, if the temperature cannot be controlled by the heater electromagnetic contactor MC2 for some reason, the temperature of the cooking oil in the oil tank will ignite. It will rise to a dangerous temperature. Therefore, a high limit HL for detecting a set temperature of about 280 ° C., which is close to the ignition danger temperature of about 310 ° C., as an abnormally high temperature is installed in the oil tank.

The high limit HL has a plurality of contacts L11 and L12, and one of the contacts L11 (L11 shown on the left side in FIG. 1) is used with respect to the control unit CB as shown in FIG. 3 (16). An abnormally high temperature detection signal is sent to shut off (OFF) the signal circuits C1 and C2 of the main magnetic contactor MC1 and the heater magnetic contactor MC2. However, FIG. 3 (17) shows only the case where the signal circuit C1 of the main magnetic contactor MC1 is cut off (OFF). In the embodiment of FIG. 1, the signal circuit C1 is directly cut off by using the other contact L12 (L12 shown on the right side in FIG. 1) separately from the cutoff of the signal circuits C1 and C2 by the control unit CB. The double safety is ensured.

In a normal case, when the signal circuits C1 and C2 are turned off, the main electromagnetic contactor MC1 and the heater electromagnetic contactor MC2 are turned off, the energization to the heater H is cut off, and a fire can be prevented. When the control unit CB cuts off (OFF) the signal circuit to the main magnetic contactor MC1, the contact S1 of the main magnetic contactor MC1 is cut off (OFF), and the relay contact R1 of the relay R that moves in conjunction with this is also cut off (OFF). The control unit CB recognizes the cutoff (OFF) of the relay contact R1.

When the main magnetic contactor MC1 is normal, the energization is cut off as described above, and the control unit CB recognizes the OFF of the relay contact R1, but when the contact S1 of the main magnetic contactor MC1 is welded, Even if the control unit CB cuts off the signal circuit C1, as shown in FIG. 3 (18), the main electromagnetic contactor MC1 is still energized, and the relay contact R1 is connected to the contact S1 of the main magnetic contactor MC1. Similarly, it is ON as shown in FIG. 3 (19).

In this way, when the control unit CB detects that the relay contact R1 of the relay R is not turned off and is turned on even though the signal circuit C1 to the main magnetic contactor MC1 is cut off (OFF). , As shown in FIG. 3 (20), the control unit CB recognizes that the contact S1 of the main magnetic contactor MC1 is welded.

When the control unit CB recognizes that the contact S1 of the main magnetic contactor MC1 is welded, the control unit CB operates the alarm unit A as shown in FIG. 3 (21). The alarm unit A notifies the abnormality by a display and a buzzer sound. The operation of the alarm unit A cannot be canceled by turning off the power switch of the electric fryer, but can be canceled only by manually turning off the breaker ELB as shown in FIG. 3 (22), and is shown in FIG. 3 (23). As a result, the alarm unit A stops its operation. As described above, the act of turning off the breaker ELB is required to release the alarm, and turning off the breaker ELB cuts off the energization of the heater H, so that the heating can be stopped reliably.

By turning off the circuit breaker ELB, the electric fryer itself is stopped, and both heating and alarm are stopped. However, when the breaker ELB is turned on again, the control unit CB and the main unit do not need to turn on the power switch of the electric fryer. The magnetic contactor MC1 is energized. At this time, since the contact S1 of the main magnetic contactor MC1 is welded, there is a danger that the heater H will be energized. However, since the control unit CB does not recognize the output of the drive signal to the main magnetic contactor MC1 or the interruption of the relay contact R1, it recognizes that the contact S1 of the main magnetic contactor MC1 is welded, and causes the alarm unit A to be alerted. Make it work. In this way, even if there is no abnormally high temperature detection signal from the high limit HL, an alarm is issued to further improve safety.

The safety device for the electric fryer shown in FIG. 1 is provided with a relay R outside the OUT side of the main magnetic contactor MC1, but a relay R may be provided outside the OUT side of the heater magnetic contactor MC2. However, relays R may be provided at two locations outside the OUT side of the main magnetic contactor MC1 and the heater magnetic contactor MC2.

The electric fryer provided with the safety device according to the first embodiment has been described above with reference to FIGS. 1 and 3, but the electric fryer equipped with the safety device according to the second embodiment shown in FIG. 2 will be described below. ..
The only difference between the first embodiment and the second embodiment is the difference in how to use the high limit HL. That is, in the first embodiment, the high limit HL uses the contact L11, the control unit CB cuts off the signal circuit to the main magnetic contactor MC1 and the heater magnetic contactor MC2, and the contact L12 is used to cut off the main electromagnetic wave. The signal circuit of the contactor MC1 is directly cut off to turn off the energization of both magnetic contactors MC1 and MC2, but the high limit LH in the second embodiment uses the contact L21 to the control unit CB. The signal circuit to the main magnetic contactor MC1 and the heater magnetic contactor MC2 is cut off to turn off the energization of both magnetic contactors MC1 and MC2, but the other contacts L22 utilize this to heat the heater. The current-carrying circuit to H is directly cut off.
As a result, it was possible to ensure safety in multiple layers.

RST ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Power supply ELB ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Breaker CB ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Control unit MC1 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Main electromagnetic contactor S1 ・ ・ ・ ・ ・ Main electromagnetic contactor contact R ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Relay R1 ・ ・ ・ ・ ・ Relay contact MC2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Heater Electromagnetic contactor S2 ・ ・ ・ ・ ・ Heater Electromagnetic contactor contact H ・ ・ ・ ・ ・ ・ Heating heater TH ・ ・ ・ ・ ・··············································································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Signal circuit A ・ ・ ・ ・ ・ ・ ・ Alarm unit

Claims (6)

It ’s a safety device for electric fryer.
The electric fryer is arranged so as to be supplied with power from a breaker installed outside the electric fryer, and the electric fryer is supplied with a heating heater installed in an oil tank and a device supplied with power from the breaker. a control unit for controlling the whole, an electromagnetic contactor for controlling the energization to the driving signal thus from the breaker to the heater from the control unit, the power supply to turn on or off the supply operation of said drive signal by the controller a switch, disposed in said oil tank, by sensing an abnormally high temperature possess the abnormally high temperature detection device for output the abnormally high temperature detection signal to the control unit,
The output side of the electromagnetic contactor of the electric fryer, relay having relay contacts interlocked with the contact and cut off the contact of the electromagnetic contactor are provided, contact or interruption of the relay contacts is input to the control unit and the relay and the control unit is connected to,
When the control unit receives the abnormally high temperature detection signal from the abnormally high temperature detection unit, wherein even though not emit a drive signal to the electromagnetic contactor, which detects that the relay contact of the relay is not interrupted Recognizes that there is welding to the contact of the electromagnetic contactor, operates the alarm unit by a command, and continues the operation of the alarm unit even when the power switch is turned off, so that the alarm can be issued only by turning off the breaker. are to prevent released by cutting the breaker, thereby interrupting the power supply to the heater of the electric fryer, safety device for an electric fryer, characterized in that to release the alarm. When the breaker is turned on again after the alarm is released by turning off the breaker, the control unit is energized without turning on the power switch, and the control unit operates the alarm unit. The safety device for an electric fryer according to claim 1. Before SL electromagnetic contactor consists of a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic contactor and than main electromagnetic contactor is installed on the heater side,
Before SL relay, the safety device of an electric fryer according to claim 1 or 2, characterized in that provided on the output side of the main magnetic contactor. Before SL electromagnetic contactor consists of a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic contactor and than main electromagnetic contactor is installed on the heater side,
Before SL relay, the main magnetic contactor on the output side and the heater electromagnetic contactor of the safety device of an electric fryer according to claim 1 or 2, characterized in that it comprises two relays provided on the output side. Before SL electromagnetic contactor consists of a main electromagnetic contactor which is placed on the power supply side, the heater electromagnetic contactor and than main electromagnetic contactor is installed on the heater side,
Before SL relay, the safety device of an electric fryer according to claim 1 or 2, characterized in that provided on the output side of the heater electromagnetic contactor. If the previous SL abnormally high temperature detector is a high limit switch having a plurality of contacts, one contact of the said plurality of contacts are disposed on the energizing circuit of the previous SL heater, it detects an abnormally high temperature to, by blocking said contact, said regardless of whether one is aware of the welding of the contacts of the electromagnetic contactor, to any one of claims 1 to 5, wherein the power down of the heater directly Described electric fryer safety device.

Images