JPS5917251Y2 - Electric fryer heater dry cooking prevention device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heater dry-cooking prevention device for preventing the heater from dry-cooking in an electric fryer.

Typically, an electric fryer equipped with a heater is as shown in FIG.

That is, the electric fryer 1 includes an oil tank 2 that stores a certain amount of cooking oil for cooking, and a support shaft 3 (see FIG. 3) disposed inside the oil tank to heat the cooking oil in the oil tank 2. a heater H that rotates around the oil tank; a heater position detection switch S1 disposed inside the heater mounting box 8 to detect when the heater H is rotated to a predetermined position outside the oil tank; An oil temperature detector Th1 having an oil temperature thermosensing tube 4 for detecting the temperature of the cooking oil in the oil tank 2, and an oil temperature detector Th1 having an oil temperature thermosensing cylinder 4 for detecting the temperature of the cooking oil in the oil tank 2, and a dry heating of the heater where the heater H is heated and reaches an abnormally high temperature even though there is not enough cooking oil in the oil tank 2. A heater empty cooking detector Th2 having an empty cooking prevention thermosensitive tube 5 for preventing the occurrence of cooking is included (note that 9 is a wire mesh container for cooking).

Conventionally, oil temperature detector Th1, heater empty detector Th
2 and the heater position detection switch S1 are connected in series with each other as shown in FIG.
A contact point a is connected to a terminal A of an electromagnetic contactor (heater heating controller) MS that controls the energization of the heater H, and this terminal A is connected to a terminal B via a coil, which is further connected to a terminal M of the power source.
It is connected to the.

When the coil between the terminals A and B of the electromagnetic contactor MS is energized, the contacts de, fg, and hi are closed, and the heater H is heated.

Here, the reason for providing the heater position detection switch S1 will be explained.

Normally, when rotating the heater H inside the oil tank out of the oil tank to clean the inside of the oil tank, it is necessary to open the power switch SW of the electric fryer or forcibly open the contact of the oil temperature detector Th1. , the heater position detection switch S1 is turned on/off.
Since the power supply to the heater H can be stopped regardless of whether it is off, it is possible to prevent the heater H from running dry, but in reality, neither the power switch SW nor the contact of the oil temperature detector Th1 is opened. There are times when the heater H is rotated outside the oil tank (see Figure 4), and in this case, the heater runs dry outside the oil tank, so to avoid this, a heater position detection switch S1 is provided. .

However, in such conventional electric fryers, when the heater H in the oil tank is lifted out of the oil tank and rotated to a predetermined position, the heater position detection switch S1 is activated and its contacts are switched between a-C, x, and b-c. Instead, with the heater H de-energized, the cooking oil in the oil tank is drained through the oil drain lever 7 and the oil drain pipe 6 (see Fig. 2).

When the heater H is rotated again into the oil tank after cleaning the inside of the oil tank, the contact point of the heater position detection switch S1 moves forward from l) -c to a -C side. Instead, energization of the heater H is started.

However, at this time, since cooking oil has not yet been supplied to the oil tank, the heater H becomes dry, and the dry cooking detector T
The heater continues to be heated until h2 detects the abnormally high temperature of the heater and opens its contact.

When such a heater runs dry, it not only shortens the product life of the heater, but also causes the cooking oil adhering to the surface of the heater to thermally decompose and change in quality, and this adheres to the surface of the heater. This decreases the thermal conductivity of the heater and increases the power consumption of the heater.

In the worst case scenario, the cooking oil adhering to the surface of the heater may be heated and combusted, leading to a fire accident.

Furthermore, if such heating of the heater is repeated many times, the product life of the dry heating detector Th2 is shortened, resulting in malfunction.

The present invention has been made to solve the above-mentioned drawbacks, and its main purpose is to provide a device for preventing the heater from running dry in an electric fryer, which prevents the heater from running dry even when the heater is taken out and put in and out of the oil tank. The purpose is to

With this purpose in mind, the electric fryer heater dry cooking prevention device of the present invention includes an oil tank that stores cooking oil, a heater that can be put in and taken out of the oil tank to heat the cooking oil, and an oil temperature sensor that detects the temperature of the cooking oil in the oil tank. a detector, a dry-heating detector that prevents the heater from dry-heating, a heater position detector that detects the position of the heater,
and a heater heating controller for controlling heating of the heater, the oil temperature detector and the dry cooking detector are connected in series, and the serially connected combination is connected to the heater heating controller via the heater position detector. In a heater dry cooking prevention device for electric fryers connected in series, the dry cooking prevention device has a relay having one end connected to a heater heating controller and the other end connected to a heater position detector, and the relay One end of the normally open contact is connected to the other end of the relay, and the other end is connected between the combination and the heater position detector, and the normally closed contact of the relay is connected between the heater position detector and the heater heating controller. It is characterized by being equipped with a dry cooking prevention circuit connected between the two.

Next, the heater dry cooking prevention device of the present invention will be explained with reference to the drawings.

FIG. 6 is an electrical circuit diagram showing the heater dry heating prevention circuit of the present invention, and the same components as in FIG. 5 are given the same reference numerals.

As shown in FIG. 6, one end of the relay X1 is connected to the terminal B of the electromagnetic contactor (heater heating controller) MS, and the normally open contact of the relay X1 is connected to the other end of the relay X1. One end and the contact point of the heater position detection switch S1 described above are connected.

The other end of the normally open contact of the relay X1 is connected to the empty cooking detector T.
h2 and the contact C of the heater position detection switch S1.

Further, the normally closed contact of the relay X1 is connected between the terminal A of the electromagnetic contactor MS and the contact a of the heater position detection switch S1.

Next, the operation of the heater dry cooking prevention device of the present invention will be explained.

Before the power switch SW is closed, cooking oil is supplied to the oil tank 2, and the temperature inside the tank is lower than the set temperature T1 detected by the oil temperature detector Th1, and the contact of the oil temperature detector Th is closed. are doing.

On the other hand, the set temperature T detected by the empty heating detector Th2 of the heater
2 is higher than the set temperature T1 of the oil temperature detector Th<(T
I<T2), so the contact of the dry cooking detector Th2 is closed.

Further, since the heater H is located in the oil tank as shown in FIG. 3, the contacts C and a of the heater position detection switch S1 are electrically connected.

Therefore, when the power switch SW of the electric fryer is closed, the conduction to the relay X1 is cut off, and this causes the normally closed contacts of the oil temperature detector Th, the dry cooking detector Th2, the heater position detection switch S1, and the relay X1. The coil between the terminals A and B of the electromagnetic contactor MS is energized through the coil, and the contacts d-e, f-g, and h-i of the electromagnetic contactor MS are closed.

As a result, the heater H is energized and the cooking oil in the oil tank is heated.

Then, when the temperature of the cooking oil in the oil tank reaches the set temperature T1 of the oil temperature detector Th1, the oil temperature detector Th detects this and opens its contacts, turning off the current to the coil of the electromagnetic contactor MS. It stops and the contacts d-e, f-g, and hi are opened.

As a result, the power supply to the heater H is stopped, and the heating action of the heater on the cooking oil is stopped.

Furthermore, when the temperature of the cooking oil in the oil tank falls below the set temperature T1 of the oil temperature detector Th1, the contact of the oil temperature detector Th is closed and the heater H is heated again by energizing the coil of the electromagnetic contactor MS. In this way, the cooking oil in the oil tank is maintained at a cooking temperature near temperature T1.

Next, when the heater H in the oil tank is rotated to the outside of the oil tank in order to clean the inside of the oil tank while the heater is performing a heating action as described above (see Figure 4), the heater position can be detected. Switch S1 detects this and switches its contact from ca to Cb.

This causes the relay X1 to conduct through the oil temperature detector Th1, the dry cooking detector Th2, and the contact C-b of the detection switch S1, so that the normally open contact of the relay X1 is closed and the normally closed contact is opened.

In this way, the relay X1 is self-maintained by closing its normally open contact, and the power supply to the heater H is stopped by stopping the power supply to the coil of the electromagnetic contactor MS.

Next, the cooking oil in the oil tank 2 is discharged to the outside of the machine via the oil drain lever 7 and the oil drain pipe 6, so that the inside of the tank can be cleaned.

After that, when the heater is rotated into the oil tank again, the contact point of the heater position detection switch S1 switches from c-1) to c-a, but the temperature inside the oil tank is the set temperature T of the oil temperature detector Th1.
1, the contacts of the oil temperature detector Th and the empty cooking detector Th2 are closed, and therefore the relay X1 remains self-held via its normally open contacts.

Therefore, the normally closed contact of relay X1 remains open,
Since the coil of the electromagnetic contactor MS is not energized, the heater is not energized.

Therefore, even if the heater H is rotated into the oil tank as shown in FIG. 3 when there is no cooking oil in the oil tank, the heater H will not be heated and dry cooking of the heater will be prevented.

When it is desired to replenish and heat the cooking oil in the oil tank, the contacts of the power switch SW or the oil temperature detector Th are opened to release the self-holding of the relay X1, and then the power switch SW and the oil temperature When the contact point of the detector Th1 is closed again, the initial state is returned and cooking oil can be heated and cooking can be performed by the same operation as described above.

As described above, the heater dry cooking prevention device for an electric fryer of the present invention has a relay whose one end is connected to an electromagnetic contactor and the other end is connected to a heater position detector, and the normally open contact of the relay is connected to one end. is connected to the other end of the relay, the other end is connected between the dry cooking detector and the heater position detector, and the normally closed contact of the relay is connected between the heater position detector and the electromagnetic contactor. Since it is equipped with a dry-heating prevention circuit, the heater will not run dry even if the heater is taken in and out of the oil tank.

In addition, by preventing dry heating of the heater, the product life of parts such as the heater and heater drying detector can be extended, and the cooking oil attached to the surface of the heater undergoes thermal decomposition and changes in quality. Since the heat conductivity of the heater is not reduced and the power consumption of the heater is not increased (that is, there is no wastage of power).

Furthermore, since the heater is prevented from heating up to an abnormally high temperature, it is possible to prevent a fire from occurring due to cooking oil adhering to the heater.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the electric fryer when the wire mesh container is placed in the oil tank, Figure 2 is a plan view of the electric fryer shown in Figure 1,
Figure 3 is a side view of the electric fryer in Figure 1, and Figure 4 is a side view of the electric fryer in Figure 1.
In the figure, a side view showing the state when the heater is rotated clockwise around its spindle (outside the oil tank), Figure 5 is an electric circuit diagram of a conventional heater dry cooking prevention device, and Figure 6 is an electric circuit diagram of a conventional heater dry heating prevention device. The figure is an electrical circuit diagram of a heater dry cooking prevention device equipped with a dry heating prevention circuit according to the present invention. 1... Electric fryer, 2... Oil tank, 3
......Spindle, 4...Oil temperature thermosensor tube,
5...Dry cooking prevention thermo-sensing cylinder, H...
Heater, MS...Magnetic contactor (heater heating controller), Sl...Heater position detection switch, Th
1...Oil temperature detector, Th2...Heater empty cooking detector, Xl...Relay, SW...
・Power switch.

Claims (1)

[Scope of utility model registration request] An oil tank that stores cooking oil, a heater that can be put in and out of the oil tank and heats the cooking oil, an oil temperature detector that detects the temperature of the cooking oil in the oil tank, an empty cooking detector that prevents the heater from running dry, and It includes a heater position detector that detects the position and a heater heating controller that controls heating of the heater, and the detectors are connected in series with each other, and the series-connected combination controls the heating of the heater via the heater position detector. In a heater dry cooking prevention device for an electric fryer connected in series to a controller, the dry cooking prevention device has a relay having one end connected to the heater heating controller and the other end connected to a heater position detector, One end of the normally open contact of the relay is connected to the other end of the relay, and the other end is connected between the combination and the heater position detector, and the normally closed contact of the relay is connected to the heater position detector and the heater heating control. An electric fryer heater dry-cooking prevention device that is equipped with a dry-cooking prevention circuit connected between the heater and the electric fryer.