JP3027294B2 - Hot plate for cooking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home and business cooking hot plate having a detachable cooking plate.

[0002]

2. Description of the Related Art There has been a conventional hot plate for cooking in which a cooking plate in which a sheathed heater is directly cast is fixed to the hot plate body, but the cooking plate can be removed from the hot plate body and washed in a round manner. It was not easy to use. Therefore, a cooking hot plate of a type in which a sheathed heater is fixed to the hot plate body side and a 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 in order to prevent the sheathed heater from being exposed to heat and becoming high in temperature. The rapid temperature rise of the hot plate body when the sheath heater is energized in a state where it is not mounted is detected by the temperature sensor, and the energization of the sheath heater is prevented. However, in this method,
Since the presence or absence of a cooking plate is detected based on the temperature rise of the hot plate body, it takes time from the energization of the sheathed heater to the detection of the presence of the cooking plate. It was not a sufficient safety measure.

[0004] In view of this, as shown in FIG.
Is placed on the sheathed heater 2, the electric contact portion 5 is turned on by the mechanical action of the cooking plate 1 pressing down the stylus 4 protruding from the hot plate body 3, and the sheathed heater 2 is turned on.
In some cases, when the cooking plate 1 is removed, the stylus 4 returns to its original state, the electrical contact portion 5 is turned off, and the power to the sheathed heater 2 is blocked. 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.

Japanese Patent Laid-Open Publication No. Hei 3-136620 discloses that a cooking plate is placed on a heating element so that a contact pressing member for turning on and off an electric contact provided on a hot plate body side is pressed and slid. There is disclosed a cooking hot plate that enables power to a heating element.

[0006]

However, in a conventional cooking hot plate, a stylus and a contact pressing member are protruded from a hot plate body and are pushed in by a cooking plate to turn on an electric contact portion. The mechanism is complicated, and may cause a malfunction depending on a malfunction of the stylus, the contact pressing member, or the electric contact portion. In addition, since the stylus and the contact pressing member protrude from the hot plate main body, even if the stylus and the contact pressing member are pushed inadvertently or by an object other than the cooking plate, the sheathed heater or the heating element It was dangerous because it turned on electricity.

[0007] In view of the above, an object of the present invention is to provide a cooking hot plate capable of confirming the presence or absence of a cooking plate with a simple structure and improving safety during use.

[0008]

According to 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 electrodes 26a to 26g. The electrode part 26 of the cooking plate 20 is attached to the plate body 21.
A plurality of electrical contacts 31a to 31g that are in contact with a to 26g are provided, a conduction detection unit 35 that detects a state of conduction between the electric contacts 31a to 31g, and the presence or absence of the cooking plate 20 according to an output signal from the conduction detection unit 35. Means for determining the presence of a cooking plate, and an electric contact 31 when it is determined that there is no cooking plate 20
a current blocking means for blocking the current flow to a to 31 g.

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

Further, the electric contacts 5 of the hot plate body
Resistance value detection unit 58 for detecting the resistance value between 5a to 55h
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 detection unit 58; and electric contacts 55a to 55 when it is determined that the predetermined cooking plate 50 is absent.
And a power supply blocking means for blocking power supply to 5h.

[0011]

In the above means for solving the problems, when the temperature of the cooking plate 20 is set to start preheating, the conduction detecting unit 35 is set.
Electrical contacts 31a-31 on the hot plate body 21 side
A conduction state is detected by applying a signal voltage between g. At this time, if the cooking plate 20 is mounted on the hot plate main body 21, the electrode portions 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, and conduction occurs. The electrical contacts 31a-
Conduction between 31g can be detected. On the other hand, if the cooking plate 20 is not mounted on the hot plate main 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.

Accordingly, the presence or absence of the cooking plate 20 is determined from the output signal from the conduction detecting unit 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, the electric contacts 31a to 31
Blocks current to g. Thereby, even when the electric contacts 31a to 31g are touched when the cooking plate 20 is not mounted, there is no electric shock and no burns, so that it is safe.

Further, when a signal voltage is applied from the resistance value detecting section 58 to the electrical contacts 55a to 55h on the hot plate body side, the resistance value of the cooking plate 50 detected at this time is determined with respect to the predetermined cooking plate 50. If it is the resistance value, it is determined that the predetermined cooking plate 50 is present, and the electric contacts 55a to 55a are determined.
Power is supplied for 5 hours. On the other hand, when the detected resistance value is not the resistance value for the cooking plate 50 set in advance, the conductive members other than the predetermined cooking plate 50 are connected to the electrical contacts 55 a to 55.
h, the electrical contacts 55a to 55h are in a conductive state, and it is determined that there is no predetermined cooking plate 50, and the power supply to the electrical contacts 55a to 55h is blocked, so that 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 comprises a cooking plate 20 on which a food is placed and heated, and a hot plate on which the cooking plate 20 is detachably mounted. The hot plate body 21 includes a plate body 21, a lid 22 that covers the cooking plate 20, and a power plug cord 23 that can be attached to and detached from the connector 21 a of the hot plate body 21. In FIG. 2,
An operation panel 24 is provided on the hot plate main body 21.

As shown in FIG. 3, the cooking plate 20 has a rectangular bottom portion and a side portion erected from the outer peripheral edge of the bottom portion are integrally formed of conductive ceramics having negative characteristics and containing silicon carbide as a main component. It becomes. The bottom rear surface is sprayed with a metal such as aluminum so as to be parallel to each other at regular intervals.
The electrode portions 26a to 26g are formed. The cooking plate 20 is electrically insulated by being covered with a non-conductive material such as non-conductive ceramics or a non-conductive film except for near both ends of the electrode portions 26a to 26g. Also,
The cooking object 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.
As shown in FIG. 4, a concave portion 30 for mounting the cooking plate 20 is formed, and each of the electrode portions 26 a to 26 of the cooking plate 20 is formed in the concave portion 30.
Electrical contacts 31a to 31g corresponding to both ends of g are protruded and attached via insulators. This electrical contact 31
When the cooking plate 20 is mounted in the recess 30, the end portions a to 31g are in contact with both ends of each of the electrode portions 26a to 26g, respectively.
As shown in the figure, the electrical contacts 31a, 31c, 31e, 31g are connected by the internal wiring of the hot plate main body 21, and the electrical contacts 31b, 31d, 31f are connected. Thereby, the surface of the cooking plate 20 has three heating surfaces A,
B and C are divided and connected in parallel. The heating surface A is formed by the left and right electrode portions 26 around the electrode portion 26b.
a, 26c, and the heating surface B is the electrode portion 2
The heating surface C is a region surrounded by the left and right electrode portions 26e and 26g with the electrode portion 26f as the center.

The electrical contacts 31b, 31d, 31f are so designed that the heating surfaces A, B, C can be individually applied with a voltage so that the respective heating surfaces A, B, C can have different temperatures. The power supply units 32a, 32b, and 32c are connected to a power outlet via a power plug cord 23. Switches 33a, 33b, and 33 are provided between the electric supply units 32a, 32b, and 32c and the heating surfaces A, B, and C, respectively.
33c are provided, and three heating surfaces A, B, and C can be selected and used. Further, a pair of electrical contacts 3
1a, a signal voltage is applied between the electrical contacts 31a to detect a conduction state, that is, whether the cooking plate 20 is mounted on the hot plate main body 21 and the electrical contacts 31a and the electrode portions 26a are in electrical contact with each other. The continuity detection unit 35, which is a cooking plate presence / absence detection unit that detects whether or not the cooking plate is present, is connected.

The electric supply units 32a, 32b, 32c,
Switches 33a, 33b, 33c and continuity detector 35
Are connected to a control unit 40 composed of a microcomputer as shown in FIG. The control unit 40 includes a voltage detection unit 43 connected in parallel to the electric supply units 32a, 32b, and 32c to detect a voltage value, and an electric supply unit 32a, 32
b, 32c are connected in series to a current detection unit 44 for detecting a current value, and a voltage detection unit 43 and a current detection unit 4 are connected.
4, each of the electric supply units 32a, 32
The function of adjusting the output voltage from the b and 32c and maintaining the temperature of the cooking plate 20 preset on the operation panel 24 is provided.

The control unit 40 also controls the conduction detection unit 35 based on the temperature setting signal of the cooking plate 20 from the operation panel 24.
And a signal voltage output function instructing to apply a signal voltage between the electrical contacts 31a, and whether or not the cooking plate 20 is mounted on the hot plate body 21 according to an output signal from the conduction detecting unit 35, that is, the cooking plate. The function of determining the presence / absence of the cooking plate 20 for determining the presence / absence of the cooking plate 20, the function of turning on the switches 33a, 33b and 33c when it is determined that the cooking plate 20 is present, and the function of energizing the electrical contacts 31a to 31g, and the absence of the cooking plate 20 The switch 33a, 33b, 33c is turned off when it is determined that there is no electricity to the electric contacts 31a to 31g, and the operation panel 24 or the alarm buzzer is used when it is determined that there is no cooking plate 20. A notification function for notifying that the board 20 is not provided.

In the above configuration, 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 type of food is controlled by the operation panel 24 to start preheating. The temperature of the cooking plate 20 is set according to the amount and amount. Then, the electrical contact 31 on the hot plate body 21 side from the conduction detecting unit 35
A conduction state is detected by applying a signal voltage between a.

At this time, if the cooking plate 20 is mounted in the concave portion 30 of the hot plate body 21, the electrode portions 26a to 26g of the cooking plate 20 and the electric contacts 31a to 31 of the concave portion 30 are provided.
g makes contact with each other, and electricity flows between the electrical contacts 31a, and the continuity between the electrical contacts 31a can be detected by the continuity detector 35. On the other hand, if the cooking plate 20 is not mounted in the concave portion 30 of the hot plate main 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 conduction detecting unit 35, and when the cooking plate 20 is present, the switches 33a, 33b, and 33c are turned on, and the electrical contacts from the respective electric supply units 32a, 32b, and 32c. 31b, 3
1d, 31f, applying a voltage to the electrical contacts 31a to 31g
The space between the electrodes 26a to 26g of the cooking plate 20 is electrically connected, and the preheating starts. Switch 3 when there is no cooking plate 20
3a, 33b and 33c are turned off, and the electrical contacts 31a to 3a are turned off.
Blocks current to 1 g. Then, the display lamp of the operation panel 24 is turned on, or an alarm is sounded by an alarm buzzer to notify that the cooking plate 20 is not present.

When the preheating starts, a voltage value and a current value applied to the cooking plate 20 are detected one by one by the voltage detection unit 43 and the current detection unit 44, and the resistance value of the cooking plate 20 is determined from the voltage value and the current value. Ask. Here, when the resistance value is small, the temperature of the cooking plate 20 is determined from the obtained resistance value by using the negative characteristic of the cooking plate 20 that the temperature is high, and the cooking plate 20 is kept until a predetermined temperature is reached. Generate heat. When the cooking plate 20 reaches the set temperature, the cooking plate 2
The voltage applied from the electric supply units 32a, 32b, and 32c is adjusted while comparing the temperature obtained from the resistance value of 0 with the set temperature, and the temperature of the cooking plate 20 is maintained at the set temperature. When the food is placed on the cooking plate 20 and the temperature of the cooking plate 20 decreases, the electric supply units 32a, 32b, 3
The heating voltage of the cooking plate 20 is increased by increasing the applied voltage from 2c, and cooking is performed while maintaining the set temperature.

When the cooking plate 20 is inadvertently removed from the hot plate main body 21 during preheating or cooking, electricity does not flow between the electrical contacts 31a to 31g, and the current from the current detection unit 44 at this time. The switches 33a, 33b, and 33c are turned off based on the output signal, and the power supply to the electrical contacts 31a to 31g is blocked.

As described above, when the temperature of the cooking plate 20 is set, a signal voltage is applied between the electrical contacts 31a on the hot plate body 21 side to detect the conduction state, and when conduction is detected, it is determined that the cooking plate 20 is present. The electric contacts 31a to 31g are energized, and if conduction is not detected, it is determined that there is no cooking plate 20 and the electric current to the electric contacts 31a to 31g is blocked. Exposed electrical contacts 3
Touching 1a to 31g is safe without electric shock or burns. In addition, even if the cooking plate 20 is inadvertently removed from the hot plate body 21 during preheating or cooking, the power supply to the electrical contacts 31a to 31g is prevented, so that it is safe.

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

Further, since the cooking plate 20 is a heating element,
Compared to a conventional case heater or a case where a cooking plate is placed on a heating element, the structure is simpler and the thermal efficiency is better, and there is no heater or the like that hinders the cleaning of the hot plate body 21, thereby improving the cleaning performance. Further, 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 26c can be detected.
Since 26 g is formed by metal spraying, the structure can be further simplified.

(Second Embodiment) In the first embodiment, when a signal voltage is applied from the conduction detecting portion 35 between the electric contacts 31a on the hot plate main body 21 side, except for the predetermined cooking plate 20 between the electric contacts 31a. When the conductive member is placed, there is a possibility that the electric contacts 31a are electrically connected to each other and that the cooking plate 20 is present, and the electric contacts 31a to 31g are energized. Therefore, in the second embodiment, a description will be given of a cooking hot plate that energizes the electric contacts only when a predetermined cooking plate is mounted.

As shown in FIG. 7, the cooking plate 50 of the cooking hot plate according to the second embodiment has a rectangular bottom and a side erected from the outer peripheral edge of the bottom integrally formed of non-conductive ceramics. It becomes. On the back side of the bottom, eight rectangular fitting grooves 51a to 51h are formed in parallel at regular intervals, respectively.
h are attached and fixed in the form of strips made of conductive ceramics containing silicon carbide as a main component in the shape of a strip, and are fixed at both ends in the longitudinal direction of the sheet heating elements 52a to 52h. The electrode portions 53a to 53h are formed by spraying the above metal. The bottom side and the front side of the side (the food contact surface) are coated with a fluororesin or the like to prevent scorching or the like from sticking, and are subjected to a non-adhesive treatment. The surfaces of the planar heating elements 52a to 52h excluding the electrode portions 53a to 53h are electrically insulated by being covered with a nonconductive material such as nonconductive ceramics or a nonconductive film.

As shown in FIG. 8, the hot plate main body is provided with electrical contacts 55a to 55h that are in electrical contact with the electrode portions 53a to 53h of the cooking plate 50, and adjacent electrical contacts 55a to 55h are provided. They are electrically connected in parallel and connected inside the hot plate body. Thereby, the surface of the cooking plate 50 has four heating surfaces E, F, G,
H and are 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 composed of the planar heating elements 52g and 52h.

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

The control unit 60 includes the operation panel 24
A signal voltage output function for instructing the resistance value detection unit 58 to apply a signal voltage between the electrical contacts 55a based on the temperature setting signal of the cooking plate 50 from the
Is compared with the resistance value of the cooking plate 50 set in advance to determine whether or not the predetermined cooking plate 50 is mounted on the hot plate body, that is, whether or not the predetermined cooking plate 50 is present. A plate presence / absence determination function and switches 57a and 57 when it is determined that a predetermined cooking plate 50 is present.
b, 57c, 57d are turned on and the electrical contacts 55a to 55h
A power supply blocking function, a switch for turning off the switches 57a, 57b, 57c, 57d when it is determined that the predetermined cooking plate 50 is not present, and blocking a power supply to the electrical contacts 55a to 55h; When it is determined that there is no plate 50, the control panel 24 or an alarm buzzer notifies the user that there is no predetermined cooking plate 50.

In the above configuration, a signal voltage is applied from the resistance value detecting section 58 to the electrical 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 a resistance value for the cooking plate 50 set in advance, it is determined that the predetermined cooking plate 50 is present, and the switches 57a, 57b,
57c and 57d are turned on, and the electric contacts 55a to 55h are energized. On the other hand, when the determined resistance value is not the resistance value for the cooking plate 50 set in advance, the predetermined cooking plate 5
When it is determined that there is no 0, the switches 57a, 57b, 57c, 5
7d is turned off, and the power supply to the electrical contacts 55a to 55h is blocked. Other configurations and operations are the same as those of the first embodiment.

As described above, the resistance value is obtained from the current value and the voltage value between the electric contacts 55a detected by the resistance value detection section 58, and the obtained resistance value is set to the preset cooking plate 5
If the resistance value is not 0, it is determined that the predetermined cooking plate 50 is not present even if a conductive member other than the predetermined cooking plate 50 is placed between the electrical contacts 55a and the electrical contact 55a. To 55 h. Therefore, even if a conductive member other than the cooking plate 50 is erroneously placed between the electrical contacts 55a, there is no risk of electric shock or burn due to touching the conductive member, and safety is improved.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made to the above-described embodiment within the scope of the present invention. For example, in the cooking plates 20 and 50 of the first and second embodiments, the heating surface may be divided into one or any number, and the number of the electricity supply units may be increased or decreased accordingly. The electrical contact connecting the conduction detection unit 35 and the resistance value detection unit 58 is
Any location between the electrical contacts that conduct when the cooking plates 20, 50 are mounted may be used.

[0035]

As is apparent from the above description, according to the first and second aspects of the present invention, a signal voltage is applied between the electric contacts on the hot plate body side to detect a conduction state, and from this conduction state, the cooking plate is detected. When the cooking plate is absent, the power supply to the electrical contacts is prevented, so that even if the user accidentally touches the exposed electrical contacts when the cooking plate is absent, there is no electric shock or burns, and the device is safe. Further, the presence / absence of the cooking plate can be detected without the mechanical operation of pressing the stylus or the contact pressing member on the cooking plate to turn on the electric contact portion, as in the related art. Can be simplified, and an accident that occurs when the stylus or the contact pressing member is inadvertently pushed by an object other than the cooking plate or by a careless person can be eliminated.
Furthermore, since the cooking plate is a heating element, the structure is simpler and more efficient than when a cooking plate is placed on a conventional sheathed heater or a heating element, and the heater is a hindrance when cleaning the hot plate body. Cleanability is improved without any problems.

Further, since the cooking plate has a negative characteristic, the temperature can be detected from the resistance value of the cooking plate without using a temperature sensor. The structure can be simplified.

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

[Brief description of the drawings]

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

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

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

FIGS. 4A and 4B show a cooking hot plate, wherein FIG. 4A is a plan view and FIG.

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

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

FIGS. 7A and 7B show a cooking plate in the cooking hot plate of the 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 a hot plate main body.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Cooking plate 21 Hot plate main body 26a-26g Electrode part 31a-31g Electric contact 35 Conduction detection part 50 Cooking plate 52a-52h Planar heating element 53a-53h Electrode part 55a-55h Electric contact 58 Resistance value detection part

Claims (3)

(57) [Claims] 1. A cooking plate made of a conductive material having a negative characteristic is provided
The cooking plate is detachably mounted on the cooking plate body, and the cooking plate is provided with a plurality of electrodes , and the electrodes are formed by metal spraying.
Is formed, the hot plate body plurality of electrical contacts in contact with the electrode portion of the cooking plate is provided, a conduction detection unit detecting the state of conduction between the electrical contacts, the output signal from the conductor through the detection unit A cooking hot plate comprising: a cooking plate presence / absence determination unit configured to determine presence / absence of the cooking plate; and a power supply blocking unit configured to block power supply to the electrical contact when it is determined that the cooking plate is absent. . 2. A cooking plate made of a conductive material having a negative characteristic is
To the cooking plate
A plurality of electrode portions are provided, and the electrode portions are formed by metal spraying.
An electrode of the cooking plate formed on the hot plate body
A plurality of electrical contacts that are in contact with the
Resistance detection unit for detecting the resistance value of the
The presence or absence of the predetermined cooking plate is determined based on these output signals.
Cooking plate presence / absence determining means, and determining that there is no predetermined cooking plate
Current blocking means for blocking power to the electrical contacts when
A cooking hot plate comprising a step and a step. 3. The cooking plate is divided into a plurality of heat generating surfaces,
Apply a voltage to the heating surface separately to make each heating surface different
Multiple electrical supply units are provided to allow temperature
And the electric supply section is connected to electric contacts corresponding to the respective heating surfaces.
3. The control according to claim 1, wherein the connection is made.
Hot plate for science.