JPH07275130A - Hot plate for cooking - Google Patents

Abstract

PURPOSE:To heighten safety by confirming the presence/absence of a cooking plate by simplified structure. CONSTITUTION:Plural electrode parts 26a-26g are provided on the cooking plate 20 that is a conductive heating unit, and plural electric contacts 31a-31g are provided on a hot plate 21. A conductive state between the electric contacts 31a-31g is detected by a conduction detecting part 35 simultaneously with the temperature setting of the cooking plate 20, and the presence/absence of the cooking plate 20 can be judged. When it is judged that no cooking plate 20 exists, the energizing of the electric contacts 31a-31g is blocked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a domestic and commercial cooking hot plate having a removable cooking plate.

[0002]

2. Description of the Related Art Some conventional cooking hot plates have a cooking plate directly cast with a sheathed heater fixed to the hot plate body. However, the cooking plate can be removed from the hot plate body and washed in its entirety. No, it was not easy to use. Therefore, a hot plate for cooking in which the sheathed heater is fixed to the hot plate body side and the cooking plate is placed on the sheathed heater is often used.

In this type of cooking hot plate, when the cooking plate is not placed on the sheathed heater, the cooking plate is heated to prevent the sheathed heater from generating heat and becoming high in temperature. The temperature sensor detects a rapid temperature rise of the hot plate main body when the sheath heater is energized in a state where the sheath heater is not placed, and the energization of the sheath heater is blocked. However, with this method,
Since the presence or absence of the cooking plate is detected by the temperature rise of the hot plate body, it takes time to detect the presence or absence of the cooking plate after energizing the sheath heater, and touching the exposed sheath heater during that time may cause burns. It was not a sufficient safety measure.

In view of this, as shown in FIG. 9, the cooking plate 1
When placed on the sheathed heater 2, the cooking plate 1 pushes down the stylus 4 protruding from the hot plate body 3 to turn on the electric contact portion 5 to turn on the sheathed heater 2.
In some cases, when the cooking plate 1 is removed, the stylus 4 returns to its original state and the electric contact portion 5 is turned off to prevent the sheath heater 2 from being energized. This makes it possible to detect the presence or absence of the cooking plate 1 before energizing the sheathed heater 2 and prevent energization of the sheathed heater 2.

Further, in Japanese Patent Laid-Open No. 3-136620, by placing a cooking plate on a heating element, a contact pressing member for turning on / off an electric contact provided on the hot plate body side is pressed and slid. Disclosed is a hot plate for cooking that enables electricity to be applied to a heating element.

[0006]

However, in the conventional hot plate for cooking, the stylus and the contact pressing member are projected from the main body of the hot plate, and the electric contact is turned on by pushing them in with the cooking plate. The mechanism is complicated, and it may cause a failure depending on the operation failure of the stylus, the contact pressing member, or the electric contact portion. Also, since the stylus and contact pressing member protrude from the hot plate body, even if the stylus and contact pressing member are pushed in by something other than the cooking plate or inadvertently, it is determined that there is a cooking plate and the sheathed heater or heating element is detected. It was dangerous because it turned on electricity.

In view of the above, it is an object of the present invention to provide a cooking hot plate capable of confirming the presence or absence of a cooking plate with a simple structure and enhancing safety during use.

[0008]

According to the means for solving the problems of the present invention, as shown in FIG. 1, the cooking plate 20 is a conductive heating element, and the cooking plate 20 is provided with a plurality of electrode portions 26a to 26g. The electrode portion 26 of the cooking plate 20 is attached to the plate body 21.
A plurality of electric contacts 31a to 31g that contact a to 26g are provided, and the presence or absence of the cooking plate 20 is determined by a conduction detection unit 35 that detects the state of conduction between the electric contacts 31a to 31g and an output signal from the conduction detection unit 35. Means for determining the presence or absence of the cooking plate, and an electric contact 31 when it is determined that the cooking plate 20 does not exist.
and an energization blocking means for blocking energization to a to 31 g.

Further, a cooking plate 20 molded of a negative characteristic conductive material or a cooking plate 50 in which planar heating elements 52a to 52h molded of a negative characteristic conductive material are arranged on the back side is used. Electrode portions 26a to 2 on the cooking plates 20 and 50
6g and 53a-53h are formed by thermal spraying of metal.

Furthermore, the electrical contacts 5 of the hot plate body
Resistance value detection unit 58 for detecting the resistance value between 5a to 55h
And a cooking plate presence / absence determining means for determining the presence / absence of a predetermined cooking plate 50 based on an output signal from the resistance value detecting unit 58, and electrical contacts 55a-5 when it is determined that the predetermined cooking plate 50 does not exist.
It is provided with an energization blocking means for blocking energization to 5h.

[0011]

In the means for solving the above problems, when the temperature of the cooking plate 20 is set to start preheating, the conduction detecting portion 35
To the electrical contacts 31a to 31 on the hot plate body 21 side
A signal voltage is applied between g to detect the conduction state. At this time, if the cooking plate 20 is attached to the hot plate body 21, the electrodes 26a to 26g of the cooking plate 20 and the electrical contacts 31a to 31g come into contact with each other, and electricity flows between the electrical contacts 31a to 31g to establish continuity. The detection unit 35 causes the electrical contacts 31a to
It is possible to detect conduction between 31 g. On the other hand, if the cooking plate 20 is not attached to the hot plate body 21, electricity does not flow between the electrical contacts 31a to 31g, and conduction between the electrical contacts 31a to 31g cannot be detected.

Therefore, the presence or absence of the cooking plate 20 is judged from the output signal from the conduction detecting section 35, and when the cooking plate 20 is present, the electric contacts 31a to 31g are energized to start preheating. When there is no cooking plate 20, electric contacts 31a to 31
Prevents energization of g. Accordingly, even when the electric contacts 31a to 31g are touched when the cooking plate 20 is not attached, it is safe without electric shock or burn.

When a signal voltage is applied from the resistance value detector 58 to the electric contacts 55a to 55h on the hot plate body side, the resistance value of the cooking plate 50 detected at this time is relative to the cooking plate 50 whose preset value is set. When it is a resistance value, it is determined that there is a predetermined cooking plate 50, and the electrical contacts 55a-5
Energize for 5h. On the other hand, when the detected resistance value is not the preset resistance value for the cooking plate 50, the conductive member other than the predetermined cooking plate 50 causes the electrical contacts 55a to 55.
Even if the electric contacts 55a to 55h are placed on the h, and the electric contacts 55a to 55h are in the conductive state, it is determined that there is no predetermined cooking plate 50, and the electric contacts 55a to 55h are prevented from being energized, so that the safety is improved. .

[0014]

【Example】

(First Embodiment) As shown in FIG. 2, a cooking hot plate according to a first embodiment of the present invention includes a cooking plate 20 on which food is placed and heated, and a hot plate on which the cooking plate 20 is detachably mounted. The plate main body 21, a lid 22 that covers the cooking plate 20, and a power plug cord 23 that is detachably attached to the connector 21 a of the hot plate main body 21 are provided. In addition, in FIG.
Reference numeral 24 denotes an operation panel provided on the hot plate body 21.

As shown in FIG. 3, the cooking plate 20 has a rectangular bottom portion and a side portion standing upright from the outer peripheral edge of the bottom portion integrally formed of a negative characteristic conductive ceramics containing silicon carbide as a main component. It becomes. The back surface of the bottom is sprayed with a metal such as aluminum by a certain distance so that it is parallel to each other.
Book electrode portions 26a to 26g are formed. The cooking plate 20 is covered with a non-conductive material such as non-conductive ceramics or a non-conductive film except for the vicinity of both ends of the electrode parts 26a to 26g, and is electrically insulated. Also,
The cooking product mounting surface (front surface) of the cooking plate 20 is coated with a fluororesin so that scorching or the like does not stick.

As shown in FIG.
4, a recess 30 for mounting the cooking plate 20 is formed, and the electrode parts 26a to 26 of the cooking plate 20 are formed in the recess 30.
Electrical contacts 31a to 31g corresponding to both ends of g are projected and attached via an insulator. This electrical contact 31
a to 31 g are brought into contact with both ends of each of the electrode portions 26 a to 26 g when the cooking plate 20 is attached to the recess 30, respectively.
As shown in FIG. 3, the internal contacts of the hot plate body 21 connect the electrical contacts 31a, 31c, 31e, 31g, and the electrical contacts 31b, 31d, 31f. As a result, the surface of the cooking plate 20 has three heating surfaces A,
It is divided into B and C and connected in parallel. The heat generating surface A is centered on the electrode portion 26b, and the left and right electrode portions 26 are
It is a region surrounded by a and 26c, and the heat generating surface B is the electrode portion 2
6d is a region surrounded by the left and right electrode parts 26c and 26e, and the heat generating surface C is a region surrounded by the left and right electrode parts 26e and 26g about the electrode part 26f.

Further, to the electric contacts 31b, 31d, 31f, it is possible to separately apply a voltage to the heating surfaces A, B, C so that the heating surfaces A, B, C have different temperatures. The power supply parts 32a, 32b, 32c, which are connected to power outlets via the power plug cord 23, are connected. Between the electricity supply parts 32a, 32b, 32c and the respective heat generating surfaces A, B, C, switches 33a, 33b,
33c is arranged, and three heating surfaces A, B, C can be selected and used. Furthermore, a pair of electrical contacts 3
To 1a, a signal voltage is applied between the electric contacts 31a to detect the conduction state, that is, whether the cooking plate 20 is attached to the hot plate body 21 and the electric contacts 31a and the electrode portion 26a are in electrical contact with each other. A continuity detecting unit 35, which is a cooking plate presence / absence detecting unit that detects whether or not the cooking plate is present, is connected.

The electricity supply units 32a, 32b, 32c,
Switches 33a, 33b, 33c and continuity detection unit 35
Is connected to a control unit 40 including a microcomputer as shown in FIG. The control unit 40 includes a voltage detection unit 43 that is connected in parallel to the electricity supply units 32a, 32b, and 32c to detect a voltage value, and electricity supply units 32a and 32.
b and 32c, which are connected in series to a current detection unit 44 that detects a current value, and are connected to the voltage detection unit 43 and the current detection unit 4
4 according to the output signal from each of the electric supply units 32a, 32
It has a function of adjusting the output voltage from b and 32c and maintaining the temperature of the cooking plate 20 preset by the operation panel 24.

Further, the control unit 40, based on the temperature setting signal of the cooking plate 20 from the operation panel 24, the conduction detecting unit 35.
Whether the cooking plate 20 is attached to the hot plate body 21 by the signal voltage output function for instructing to apply a signal voltage between the electric contacts 31a and the output signal from the conduction detecting unit 35, that is, the cooking plate There is no cooking plate 20, a function of determining whether or not the cooking plate 20 is present, a function of turning on the switches 33a, 33b, 33c to energize the electrical contacts 31a to 31g when it is determined that the cooking plate 20 is present. When it is judged that the switch 33a, 33b, 33c is turned off to prevent the electric contacts 31a to 31g from being energized, and when it is judged that there is no cooking plate 20, cooking is performed by the operation panel 24 or the alarm buzzer. It has a notifying function for notifying that there is no plate 20.

In the above structure, as shown in FIG. 6, the power plug cord 23 attached to the connector 21a of the hot plate body 21 is connected to a power outlet and the operation panel 24 is used to start preheating. The temperature of the cooking plate 20 is set according to the amount and amount. Then, from the continuity detection unit 35 to the electrical contact 31 on the hot plate body 21 side.
A signal voltage is applied between a and the conduction state is detected.

At this time, if the cooking plate 20 is mounted in the recess 30 of the hot plate body 21, the electrode portions 26a to 26g of the cooking plate 20 and the electrical contacts 31a to 31 of the recess 30 are provided.
With g, the electricity flows between the electrical contacts 31a, and the conduction detector 35 can detect conduction between the electrical contacts 31a. On the other hand, if the cooking plate 20 is not mounted in the recess 30 of the hot plate body 21, electricity does not flow between the electrical contacts 31a, and conduction between the electrical contacts 31a cannot be detected. Therefore, the presence or absence of the cooking plate 20 is determined from the output signal from the continuity detecting unit 35, and when the cooking plate 20 is present, the switches 33a, 33b, 33c are turned on to make electrical contacts from the respective electric supply units 32a, 32b, 32c. 31b, 3
Voltage is applied to 1d and 31f, and electrical contacts 31a to 31g
And the electrodes 26a to 26g of the cooking plate 20 are electrically connected to each other to start preheating. Switch 3 when there is no cooking plate 20
3a, 33b, 33c are turned off, and electrical contacts 31a-3
Prevents energization of 1g. Then, the display lamp of the operation panel 24 is turned on or an alarm sound is emitted by an alarm buzzer to notify that there is no cooking plate 20.

When the preheating is started, the voltage detection unit 43 and the current detection unit 44 detect the voltage value and the current value applied to the cooking plate 20 one by one, and the resistance value of the cooking plate 20 is determined from the voltage value and the current value. Ask. Here, by utilizing the negative characteristic of the cooking plate 20 that the temperature is high when the resistance value is small, the temperature of the cooking plate 20 is judged from the obtained resistance value, and the cooking plate 20 is kept until it reaches a preset temperature. Heat up. When the cooking plate 20 reaches the set temperature, the cooking plate 2
The temperature of the cooking plate 20 is maintained at the set temperature by adjusting the voltage applied from the electric supply units 32a, 32b, 32c while comparing the temperature obtained from the resistance value of 0 with the set temperature. In addition, when the food is placed on the cooking plate 20 and the temperature of the cooking plate 20 drops, the electricity supply units 32a, 32b, 3
The applied voltage from 2c is increased to increase the amount of heat generated by the cooking plate 20, and cooking is performed while maintaining the set temperature.

When the cooking plate 20 is unintentionally removed from the hot plate body 21 during preheating or cooking, electricity stops flowing between the electrical contacts 31a to 31g, and the current detecting portion 44 at this time The switches 33a, 33b, 33c are turned off based on the output signal to prevent the electric contacts 31a to 31g from being energized.

As described above, when the temperature of the cooking plate 20 is set, a signal voltage is applied between the electric contacts 31a on the hot plate body 21 side to detect the conduction state, and when the conduction is detected, it is determined that the cooking plate 20 is present. Then, the electric contacts 31a to 31g are energized, and if the conduction is not detected, it is determined that there is no cooking plate 20 and the electric contacts 31a to 31g are energized. Exposed electrical contact 3
Even if it touches 1a to 31g, it is safe without electric shock or burn. Further, even if the cooking plate 20 is unintentionally removed from the hot plate body 21 during preheating or cooking, the electrical contacts 31a to 31g are prevented from being energized, which is safe.

Moreover, the presence or absence of the cooking plate 20 can be electrically detected without any mechanical operation such as pressing the stylus or contact pressing member with the cooking plate to turn on the electric contact portion as in the conventional case. The structure for detecting the presence or absence of the cooking plate 20 can be simplified, and an accident caused by pushing the stylus or the contact pressing member with something other than the cooking plate or inadvertently can be eliminated.

Furthermore, since the cooking plate 20 is used as a heating element,
The structure is simple and the thermal efficiency is high as compared with the conventional case where the cooking plate is placed on the sheathed heater or the heating element, and moreover, there is no heater or the like which obstructs the cleaning of the hot plate body 21, and the cleaning property is improved. Moreover, since the cooking plate 20 has a negative characteristic, the temperature can be detected from the resistance value of the cooking plate 20 without using a temperature sensor, and the electrode portions 26a to 26a.
Since 26 g is formed by thermal spraying of metal, the structure can be further simplified.

(Second Embodiment) In the first embodiment, when a signal voltage is applied from the continuity detecting section 35 to the electric contacts 31a on the hot plate body 21 side, a predetermined cooking plate 20 is provided between the electric contacts 31a. If the electrically conductive member is placed, it may be determined that the cooking plate 20 is present due to conduction between the electric contacts 31a, and the electric contacts 31a to 31g may be energized. Therefore, in the second embodiment, a cooking hot plate in which electric contacts are energized only when a predetermined cooking plate is mounted will be described.

As shown in FIG. 7, the cooking plate 50 of the cooking hot plate of the second embodiment has a rectangular bottom portion and side portions standing upright from the outer peripheral edge of the bottom portion integrally formed of non-conductive ceramics. It becomes. Then, on the back side of the bottom portion, eight rectangular fitting grooves 51a to 51h are formed in parallel at regular intervals, and these fitting grooves 51a to 51h are formed.
The sheet heating elements 52a to 52h having negative characteristics, which are formed in a strip shape by conductive ceramics containing silicon carbide as a main component, are fitted and fixed to h, and aluminum or the like is attached to both ends in the longitudinal direction of the sheet heating elements 52a to 52h. Electrodes 53a to 53h are formed by spraying the metal of No. The bottom side and the front side of the side portion (the food contact surface) are coated with a fluororesin or the like to prevent them from sticking to them, and are subjected to a non-adhesive treatment. The surfaces of the sheet heating elements 52a to 52h other than the electrode portions 53a to 53h are covered with a non-conductive material such as non-conductive ceramics or a non-conductive film to be electrically insulated.

Further, as shown in FIG. 8, the hot plate body is provided with electric contacts 55a to 55h for making electrical contact with the electrode portions 53a to 53h of the cooking plate 50, and adjacent electric contacts 55a to 55h are provided. They are electrically connected in parallel and connected inside the hot plate body. As a result, the surface of the cooking plate 50 has four heating surfaces E, F, G,
It is divided into H and connected in parallel.
The heating surface E is a region composed of the planar heating elements 52a and 52b, the heating surface F is a region composed of the planar heating elements 52c and 52d, and the heating surface G is a region composed of the planar heating elements 52e and 52f. The heating surface H is an area including the sheet heating elements 52g and 52h.

Further, a voltage is separately applied to each of the heat generating surfaces E, F, G, H to each of the electric contacts 55a to 55h so that each of the heat generating surfaces E, F, G, H has a different temperature. The electric supply units 56a, 56b, 56c, and 56d are connected so that the above can be performed. These electricity supply units 56a, 56b, 5
Switches 57a, 57b, 57c and 57d are arranged between 6c and 56d and the respective heat generating surfaces E, F, G and H,
The four heating surfaces E, F, G and H can be selected and used. Further, the pair of electrical contacts 55a are replaced by the electrical contacts 55a instead of the continuity detecting unit 35 in the first embodiment.
A resistance value detection unit 58, which is a cooking plate presence / absence detection unit for applying a signal voltage to detect a voltage value and a current value, that is, for detecting a resistance value, is connected therebetween.

The control panel 60 includes a control panel 24.
And a resistance value detecting section 58 for instructing the resistance value detecting section 58 to apply a signal voltage between the electric contacts 55a based on the temperature setting signal of the cooking plate 50.
A cooking process in which the resistance value detected by the above is compared with a preset resistance value for the cooking plate 50 to determine whether or not the predetermined cooking plate 50 is attached to the hot plate body, that is, the presence or absence of the predetermined cooking plate 50. A plate presence / absence determining function and switches 57a, 57 when it is determined that a predetermined cooking plate 50 is present.
b, 57c, 57d are turned on to make electrical contacts 55a to 55h.
And a predetermined cooking plate 50, and a current blocking function of turning off the switches 57a, 57b, 57c, 57d to block the electric contacts 55a to 55h when it is determined that the predetermined cooking plate 50 is not present, and a predetermined cooking When it is determined that there is no plate 50, the operation panel 24 and the alarm buzzer are provided with a notification function that notifies that there is no predetermined cooking plate 50.

In the above structure, a signal voltage is applied from the resistance value detecting section 58 to the electric contact 55a on the hot plate body side, and the resistance value of the cooking plate 50 is obtained from the voltage value and current value detected at this time. When the obtained resistance value is the resistance value with respect to the preset cooking plate 50, it is determined that there is a predetermined cooking plate 50, and the switches 57a, 57b,
57c and 57d are turned on to energize the electrical contacts 55a to 55h. On the other hand, when the obtained resistance value is not the resistance value for the cooking plate 50 set in advance, the predetermined cooking plate 5
Switch 57a, 57b, 57c, 5 determined that there is no 0
7d is turned off to prevent the electric contacts 55a to 55h from being energized. The other configurations and operations are similar to those of the first embodiment.

As described above, the resistance value is obtained from the current value and the voltage value between the electrical contacts 55a detected by the resistance value detecting section 58, and the obtained resistance value is set in advance.
When the resistance value is not 0, even if a conductive member other than the predetermined cooking plate 50 is placed between the electric contacts 55a and is in a conductive state, it is determined that the predetermined cooking plate 50 does not exist, and the electric contact 55a. It is possible to prevent the energization to ~ 55h. Therefore, even if a conductive member other than the cooking plate 50 is erroneously placed between the electric contacts 55a, there is no risk of electric shock or burns when touching the electric contacts 55a, and safety is improved.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention. For example, in the cooking plates 20 and 50 of the first and second embodiments, the heat generating surface may be divided into one or any number, and the number of electricity supply units may be increased or decreased according to this. Further, the electrical contacts connecting the continuity detecting unit 35 and the resistance value detecting unit 58 are
It may be anywhere between the electrical contacts that conduct when the cooking plates 20 and 50 are attached.

[0035]

As is apparent from the above description, according to claims 1 and 2 of the present invention, a signal voltage is applied between the electric contacts on the hot plate body side to detect the conduction state, and the cooking plate is detected from this conduction state. Since the presence or absence of the cooking plate is checked to prevent the electric contacts from being energized when the cooking plate is not present, even if the exposed electrical contacts are erroneously touched when the cooking plate is not present, it is safe without electric shock or burn. In addition, the presence or absence of the cooking plate can be detected electrically without the need for mechanical operations such as pushing the stylus or contact pressing member on the cooking plate to turn on the electrical contact part, as in the conventional case. It is possible to simplify the structure for detecting, and it is possible to eliminate an accident that occurs when the stylus or contact pressing member is inadvertently pushed in by something other than the cooking plate or inadvertently.
Furthermore, since the cooking plate is used as the heating element, the structure is simpler and the thermal efficiency is better than the conventional sheathed heater or when the cooking plate is placed on the heating element, and the heater becomes an obstacle when cleaning the hot plate body. Cleanliness is improved by eliminating such problems.

Further, since the cooking plate has a negative characteristic, it is possible to detect the temperature from the resistance value of the cooking plate without using a temperature sensor, and moreover, since the electrodes are formed by spraying metal, The structure can be simplified.

According to the third aspect of the present invention, the presence or absence of a predetermined cooking plate is determined from the resistance value between the electric contacts detected by the resistance value detecting unit. Even when the member is placed and is in the conductive state, it is possible to determine that there is no predetermined cooking plate and prevent the electric contact from being energized. Therefore, even if a conductive member other than the cooking plate is erroneously placed between the electric contacts, there is no risk of electric shock or burn due to touching the electric contacts, and safety is improved.

[Brief description of drawings]

FIG. 1 is a control circuit diagram of a hot plate for cooking according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a hot plate for cooking.

FIG. 3 shows a cooking plate, (a) is a plan view, (b)
Is a side sectional view, (c) is a rear view

FIG. 4 shows a hot plate for cooking, (a) is a plan view and (b) is a side sectional view.

FIG. 5 is a diagram showing a connection state in the hot plate body.

FIG. 6 is a flowchart for detecting the presence or absence of a cooking plate in a cooking hot plate.

7A and 7B show a cooking plate of a hot plate for cooking according to a second embodiment, wherein FIG. 7A is a plan view, FIG. 7B is a side sectional view, and FIG.

FIG. 8 is a diagram showing a connection state in the hot plate body.

FIG. 9 shows a conventional cooking hot plate,
(A) is a plan view, (b) is a side sectional view

[Explanation of symbols]

 20 Cooking Plate 21 Hot Plate Main Body 26a to 26g Electrode Part 31a to 31g Electric Contact 35 Conduction Detection Part 50 Cooking Plate 52a to 52h Sheet Heating 53a to 53h Electrode Part 55a to 55h Electric Contact 58 Resistance Value Detection Part

Claims (3)

[Claims] 1. A hot plate for cooking, comprising a cooking plate on which cooking is placed and heated, and a hot plate body to which the cooking plate is detachably mounted, wherein the cooking plate is a conductive heating element. A plurality of electrode portions are provided on the cooking plate, a plurality of electrical contacts that contact the electrode portions of the cooking plate are provided on the hot plate body, and a conduction detecting unit that detects a state of conduction between the electric contacts is provided. And a cooking plate presence / absence determining unit that determines the presence or absence of the cooking plate based on an output signal from the conduction detecting unit, and an energization blocking unit that blocks energization to the electrical contacts when it is determined that the cooking plate does not exist. A hot plate for cooking characterized in that it is provided. 2. A cooking plate formed of a conductive material having a negative characteristic or a cooking plate having a planar heating element formed of a conductive material having a negative characteristic on the back side is used, and an electrode on the cooking plate is used. The hot plate for cooking according to claim 1, wherein the portion is formed by thermal spraying of a metal. 3. A cooking hot plate comprising a cooking plate for placing and heating food to be cooked, and a hot plate body for detachably mounting the cooking plate, wherein the cooking plate is a conductive heating element. A plurality of electrode portions are provided on the cooking plate, a plurality of electric contacts that come into contact with the electrode portions of the cooking plate are provided on the hot plate body, and a resistance value detection unit that detects a resistance value between the electric contacts is provided. And a cooking plate presence / absence determining means for determining the presence / absence of the predetermined cooking plate based on an output signal from the resistance value detecting section, and energizing the electric contact when it is determined that the predetermined cooking plate is not present. A hot plate for cooking, comprising: an energization preventing means.