KR20070054997A - Plate heater and steam cooking apparatus including the same - Google Patents

Abstract

The present invention relates to a planar heating heater having a PTC temperature sensor for sensing the temperature of the planar heating heater and a steam cooking apparatus including the same.

The planar heating heater according to the present invention includes a heating part formed of an insulating substrate, a heating resistor formed by a pattern printed on the insulating substrate to generate heat, and a PTC temperature sensor for sensing the heating temperature of the heating part. The temperature distribution lines are distributed downward from the center to the outside direction, and the PTC temperature sensor is arranged in the direction in which the intervals of the temperature contour lines are wide in the insulating substrate, thereby enabling accurate temperature sensing of the surface heating heater. .

Description

Plate heater and steam cooking apparatus including the same

1 is a perspective view showing a schematic structure of a steam cooking apparatus according to the present invention.

Figure 2 is a front view showing the appearance of the steam cooking apparatus according to the present invention.

3 is a cross-sectional view of the steam cooking apparatus according to the present invention.

4 is a view showing a steam generating unit and a planar heating heater included in the same.

5 is a plan view of a planar heating heater according to the present invention.

Explanation of symbols on the main parts of the drawings

1: housing, 10: cooking chamber,

20: water supply unit, 30: steam generating unit,

31: steam generating container, 50: planar heating heater,

53: heating part, 54,55: power supply terminal,

60: PTC temperature sensor. 61: PTC resistor,

62: connector.

The present invention relates to a planar heating heater and a steam cooking apparatus including the same, and more particularly to a planar heating heater having a PTC temperature sensor for sensing the temperature of the planar heating heater and a steam cooking apparatus comprising the same.

In general, the food is cooked in a gas oven or an electric oven by heating the food directly, or cooked by heating a steamed food container, or by using a microwave oven at high frequency There is a way to cook.

When cooking food directly by heating it, as in gas or electric ovens, food is oxidized in contact with oxygen contained in the air, and the taste of food is reduced. When cooking using a steaming container, too much water is contained in the food. The taste peculiar to food falls. In addition, when cooking with a microwave, the high frequency is not evenly injected into the food, the food is locally burned or less cooked, it is not possible to cook uniformly.

As an alternative to solve the shortcomings of the conventional cooking methods, a cooking apparatus for supplying and cooking food with superheated steam has been developed, and many techniques have been disclosed for cooking apparatus using superheated steam. When food is cooked using such a cooking apparatus, high temperature superheated steam is directly transmitted to the entire surface of the food, so that the food does not burn or become less ripe, and the food is tasted well by maintaining proper moisture throughout the food. An example of a cooking apparatus using such superheated steam is Japanese Laid-Open Patent Publication No. 2005-61816.

The steam cooking apparatus disclosed in Japanese Laid-Open Patent Publication No. 2005-618166 is provided with a water tank, a steam generator, a steam heating heater, and a blower to supply superheated steam to the cooking chamber and to cook food by the heat contained in the superheated steam. . At this time, the steam generator is provided with an annular sheath heater to surround the outer surface of the pot in order to generate steam by heating the water stored in the pot, steam cooking generally disclosed, including the Japanese Patent Publication The apparatus does not disclose a steam generator using a planar heating heater.

In addition, the Republic of Korea Patent Publication (Publication No. 10-2005-28970) discloses a heater manufacturing method and a heater using a PCB method, such a PCB heater is a heating resistor, power supply terminal, sensor mount and sensor, sensor connection The terminal is provided with a pattern printed on the insulating substrate.

The above-described conventional PCB type heater has a temperature gradient formed therein according to the shape of the heater when the heater generates heat. In the prior art, an attachment position of a sensor for sensing an accurate temperature is not affected by the temperature gradient. It does not disclose about.

SUMMARY OF THE INVENTION An object of the present invention is to provide a surface heating heater having a PTC temperature sensor installed at an optimal position for measuring an accurate heating temperature of the surface heating heater and a steam cooking apparatus including the same.

The present invention for achieving the above object includes a heating portion formed of an insulating substrate, a heating resistor formed by a pattern printed on the insulating substrate and generates heat, and a PTC temperature sensor for sensing the heating temperature of the heating portion, The insulating substrate has a temperature contour line distributed downward from the center portion to the outside, and the PTC temperature sensor is disposed in a wide direction of the temperature contour line in the insulating substrate for accurate temperature sensing.

In addition, the PTC temperature sensor is characterized in that provided in the central portion of the insulating substrate.

In addition, the PTC temperature sensor is characterized in that it comprises a PTC resistor that is pattern-printed on the insulating substrate, and connecting terminals provided at both ends of the PTC resistor.

In addition, the steam cooking apparatus according to the present invention is a steam cooking apparatus including a cooking chamber, a steam generating unit which is disposed outside the cooking chamber to generate steam supplied to the cooking chamber, and a planar heating heater provided in the steam generating unit. In claim 1, The planar heating heater includes a heating portion formed of an insulating substrate, a heating resistor formed by a pattern printed on the insulating substrate to generate heat, and a PTC temperature sensor for sensing the heating temperature of the heating portion, the insulation The substrate has a temperature contour line distributed downward from the center portion to the outside, and the PTC temperature sensor is disposed in the direction in which the interval of the temperature contour line is wide in the insulating substrate.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

1 is a perspective view showing a schematic structure of a steam cooking apparatus according to the present invention, Figure 2 is a front view showing the appearance of the steam cooking apparatus according to the present invention.

As shown in Figures 1 and 2, the steam cooking apparatus according to the present invention is a cooking chamber arranged so that a predetermined space is provided between the housing 1 and the housing 1 inside the housing 1 forming an external appearance. 10, a door 2 that opens and closes an open front surface of the cooking chamber 10, and a control panel 3 installed above the cooking chamber 10. In addition, the steam cooking apparatus according to the present invention, the water supply unit 20 and the steam generating unit 30, which is disposed in the space between the housing 1 and the cooking chamber 10 to supply steam to the cooking chamber 10, and one It further comprises a pair of superheated steam supply unit (40).

The cooking chamber 10 includes a top plate 11, a bottom plate 12, both side plates 13, and a back plate 14 to form a predetermined volume of internal space for cooking food. Outside the 10, the heat of the cooking chamber 10 is surrounded by a heat insulating member (not shown) so as not to escape to the outside. In addition, the outer surface of the upper plate 11 of the cooking chamber 10 is provided with a magnetron 4 for generating microwaves, and a crossflow fan 5 for cooling the magnetron 4, the steam generating unit 30, and other electrical equipment. .

A plurality of inlet holes 15 having a small size is disposed at the center of both side plates 13, and a plurality of outflow holes having a small size outside the inlet hole 15, that is, at the edge of each side plate 13. A ball 16 is provided. Preferably, the plurality of outlet holes 16 are disposed to be symmetrical on the upper, lower, front, and rear portions of the plurality of inlet holes 15. The side plate 13 of the cooking chamber 10 is formed as described above, and the steam inside the cooking chamber 10 flows into the superheated steam supply unit 40 through the inlet hole 15 and is overheated to a high temperature, and then the outlet hole 16. Through the outflow into the cooking chamber 10.

The water supply unit 20 is installed at the front of the outer side of the upper plate 11, the water supply case 21, the water supply container 22 which is detachably attached to the water supply case 21, and the water supply unit 20 And a water supply pipe 23 connecting the steam generating unit 30 and a pump 24 provided in the middle of the water supply pipe 23 to supply water to the steam generating unit 30.

Water filled in the water supply container 22 in the water supply unit 20 is pumped by the pump 24 is supplied to the steam generating unit 30 through the water supply pipe (23).

1 and 4, the steam generating unit 30 is installed in a substantially box shape on one side of the outer side of the upper plate 11, connected to the water supply pipe 23 and introduced through the water supply pipe 23. And a planar heating heater 50 formed on the lower surface of the steam generating container 31 to generate steam by heating the water contained in the steam generating container 31 to receive water. .

A water supply port 32 for connecting to the water supply pipe 23 is formed on the upper surface of the steam generating container 31, and an outlet for supplying steam generated in the steam generating container 31 to the cooking chamber 10 in the upper front. 33 is formed, and the outlet 33 is provided with a steam supply duct 34 to communicate with the steam inlet 17 of the cooking chamber 10. Therefore, the steam of the steam generating container 31 is supplied into the cooking chamber 10 through the steam supply duct 34. In addition, a drainage hole 35 is formed below one side of the steam generating container 31 to connect the drain pipe 36 for draining the residual water inside the steam generating container 31 after the cooking operation of the steam cooking device is finished.

As shown in FIG. 3, the superheated steam supply unit 40 is provided on the outer side of both side plates 13 of the cooking chamber 10, and the air inside the cooking chamber 10 flows in through the inlet hole 15 and flows out. A circulation fan 41 forcibly circulating back into the cooking chamber 10 through the ball 16, an overheated heater 42 for heating the circulating air to superheat steam, and a circulation fan 41. ) And a case 43 coupled to the side plate 13 and surrounding the overheated heater 42, and a motor 44 provided on the outside of the case 43 to drive the circulation fan 41. Accordingly, the superheated steam duct 45 is formed between the outer side of the side plate 13 and the case 43, and the circulation fan 41 and the superheated heater 42 are provided in the superheated steam duct 45, so that the cooking chamber 10 is provided. The air inside is introduced into the superheated steam duct 45 through the inlet hole 15 and superheated by the superheated heater 42, and then flows out again to the cooking chamber 10 through the outlet hole 16.

4 is a view showing a steam generating unit and a planar heating heater included in the same.

5 is a plan view of a planar heating heater according to the present invention.

Planar heating heater 50 is provided in the lower portion of the steam generating vessel 31, the planar heating heater 50, as shown in Figure 4, the insulating substrate 51, and the pattern on one surface of the insulating substrate 51 A heating part 53 formed of a printed heating resistor 52 and generating heat as much as a predetermined output according to the supply of power, and a PTC temperature sensor 60 for sensing a heating temperature of the heating part 53. It is made to include.

Planar heating heater 50 refers to a heater designed to heat the surface itself by printing a pattern of the heating resistor 52 by applying a PCB method on the insulating substrate (51). The surface heating heater 50 has a variety of advantages such as rapid heating, high temperature, easy temperature control, and quick response speed compared to general heaters such as sheath heaters. It can be widely used for various kinds of heating means as well as steam cooking equipment. In particular, in the steam cooking apparatus according to an embodiment of the present invention it is possible to generate steam quickly, even if a small amount of water in the steam generating container 31 can generate steam.

The planar heating heater 50 is provided on the lower surface of the steam generating container 31. The planar heating heater 50 is provided with a heating resistor 52 in a ladder pattern to maximize the heat transfer area.

The insulating substrate 51 provided in the planar heating heater 50 is formed of a thin plate having a substantially rectangular shape, and one surface of the insulating substrate 51 is for supplying power to the heating part 53 of the planar heating heater 50. Power supply terminals 54 and 55 are provided.

The heating unit 53 is formed of a heating resistor 52 pattern-printed on one surface of the insulating substrate 51, the resistance size of the heating resistor 52 is proportional to the intrinsic resistance value and length of the heating resistor 52 and has a cross-sectional area. Inversely, the pattern of the heat generating resistor 52 is printed on the insulating substrate 51 based on this, and even though the power supply is constant, the resistance of the heat generating resistor 52 constituting the heating unit 53 is printed differently. Can produce various sizes of output.

In addition, the output of the heating unit 53 may be variously determined in consideration of the size of the cooking chamber, the amount of steam supply required.

The output of the heating unit 53 serves to generate steam by heating the water of the steam generating container 31, when there is no water in the steam generating container 31, the temperature of the heating unit 53 is rapidly increased Since the surface heating heater 50 may be a cause of failure, the surface heating heater 50 includes a PTC temperature sensor 60 capable of sensing the temperature of the heating unit 53.

A positive temperature coffficient (PTC) resistor has a characteristic of maintaining a constant temperature at all times by changing its resistance when there is a change in ambient temperature. PTC temperature sensor is a sensor that senses the temperature by measuring the change in resistance by using the characteristics of such a PTC resistor.

In the PTC temperature sensor 60 included in the planar heating heater 50 of the present invention, the PTC resistor 61 is pattern-printed on the insulating substrate 51, and the PTC temperature sensor 60 is such a PTC resistor 61. By measuring the resistance value of the heating unit 53 to detect the heating temperature.

Since the edge portion 51a of the rectangular insulating substrate 51 is provided in contact with the lower portion 31a of the steam generating vessel 31, power is applied to the planar heating heater 50 so that the heating portion 53 generates heat. In this case, the heat of the heating part 53 is conducted to the steam generating vessel 31 side through the edge portion 51a of the insulating substrate 51 or in contact with the air, thereby causing heat transfer. Due to this heat transfer, the temperature of the insulating substrate 51 is distributed to be lowered from the center of the insulating substrate 51 toward the edge portion 51a, so that an elliptic temperature contour is formed as indicated by a dotted line in FIG. 5.

The PTC temperature sensor 60 measures the temperature by measuring the resistance value according to the installation portion of the PTC resistor 61, when the temperature gradient of the installation portion of the PTC resistor 61 becomes large, it is difficult to accurately measure the resistance value Therefore, there is a problem in that it is difficult to calculate the correct temperature.

Therefore, in order for the PTC temperature sensor 60 to exhibit an accurate temperature sensing capability, the PTC resistor 61 must be provided at a small temperature gradient in the insulating substrate 51, so that the PTC resistor 61 of the PTC temperature sensor 60 is small. The pattern is printed in a linear direction with a wide interval of temperature contours. Due to the arrangement of the PTC resistor 61, the temperature difference between both ends of the PTC resistor 61 becomes relatively small, so that accurate measurement of the resistance value can be performed, and the accurate heating temperature of the planar heating heater 50 can be calculated.

In addition, since the heat generation temperature of the central portion of the planar heating heater 50 is relatively higher than other parts, the PTC temperature sensor 60 is preferably used to detect overheating of the planar heating heater 50. It is provided in the center and the PTC resistor 61 is pattern-printed linearly in a wide direction of the temperature contour line.

In addition, both ends of the PTC resistor 61 are provided with a connection terminal 62 for transmitting the resistance value measured by the PTC resistor 61 to the outside.

Next, the manufacturing of the surface heating heater 50 will be described.

The heat generating resistor 52 is formed in a ladder pattern so that the heating part 53 is formed on the insulating substrate 51, and the interval of the temperature contour line is formed so that the PTC temperature sensor 60 is formed at the center of the insulating substrate 51. The pattern of the PTC resistor 61 is molded in this wide direction. After the molding process, the pattern printing of the heating unit 53 and the PTC resistor 61 is completed by etching the corrosive insulating substrate 51 on which the pattern is formed, and the pattern printed heating unit 53 and the PTC resistor are completed. Except for both ends of the PTC resistor 61 in which the connection terminal 62 is to be installed on the printed surface of the insulating substrate 51 for insulation of the insulating substrate 51, the insulating protective film 56 is formed, and then both ends of the PTC resistor 61 are formed. The connection terminal 62 is welded on to complete the production of the planar heating heater 50.

Next will be described with reference to the drawings for the operation of the steam cooking apparatus according to the present invention configured as described above.

When the user puts food into the cooking chamber 10 and manipulates the control panel 3 to input a cooking command, the pump 24 operates to supply the steam generating container 31 of the steam generating unit 30 to the water supply unit 20. Water is supplied.

Therefore, when a cooking command is input and water is supplied to the steam generating container 31, power is supplied to the heating part 53 of the planar heating heater 50 so as to generate the amount of steam according to the input cooking command. 50).

At this time, if water is not supplied to the steam generating container 31 or all of the supplied water becomes steam and there is no water in the steam generating container 31, a sudden temperature increase may occur. When the temperature sensor 60 detects this and the temperature of the heating unit 53 rises above a predetermined temperature, the temperature sensor 60 cuts off the power to prevent a failure of the surface heating heater 50.

In addition, the steam formed in the steam generating unit 30 by heating the surface heating heater 50 is introduced into the cooking chamber 10 through the steam supply duct 34, the steam introduced into the cooking chamber 10 is superheated steam By the operation of the circulation fan 41 of the supply unit 40, it is sent to the superheated steam duct 45 through the inlet hole 15, and the circulation fan 41 and the superheated heater 42 in the superheated steam duct 45. By switching to the superheated steam of a higher temperature is supplied to the cooking chamber 10 through a plurality of outlet holes 16 formed in each side plate 13 of the cooking chamber 10.

In this process, the air in the cooking chamber 10 is continuously overheated by the overheat heater 42 due to the operation of the circulation fan 41, and forced circulation is re-supplied into the cooking chamber 10.

After the cooking is finished, the cycle is terminated and the water stored in the steam generating container 31 is discharged to the bottom plate 12 of the cooking chamber 10 through the drain pipe 36.

As described in detail above, the planar heating heater and the steam cooking apparatus including the same according to the present invention, the PTC temperature sensor is placed in the insulation substrate of the planar heating heater in a wide direction of the temperature contour line so that the PTC temperature sensor accurately senses the temperature. It has the effect of exerting ability.

Claims (5)

Insulation board, A heating part formed of a heat generating resistor having a pattern printed on the insulating substrate to generate heat; Including a PTC temperature sensor for detecting the heating temperature of the heating unit, The insulating substrate has a temperature contour line distributed downward from the center portion to the outside, and the PTC temperature sensor is disposed in the direction in which the interval of the temperature contour line is wide in the insulating substrate for accurate temperature sensing. . The planar heating heater of claim 1, wherein the PTC temperature sensor is provided at a central portion of the insulating substrate. The planar heating heater according to claim 2, wherein the PTC temperature sensor includes a PTC resistor pattern-printed on the insulating substrate and connection terminals provided at both ends of the PTC resistor. In the steam cooking apparatus comprising a cooking chamber, a steam generating unit disposed outside the cooking chamber to generate steam supplied to the cooking chamber, and a planar heating heater provided in the steam generating unit, The planar heating heater includes a heating part formed of an insulating substrate, a heating resistor formed by a pattern printed on the insulating substrate and generating heat, and a PTC temperature sensor for sensing the heating temperature of the heating part, The insulation substrate has a temperature contour line distributed downward from the center portion to the outside direction, and the PTC temperature sensor is disposed in the direction in which the interval of the temperature contour line in the insulation substrate in a wide direction. 5. The steam cooking apparatus according to claim 4, wherein the PTC temperature sensor includes a PTC resistor pattern-printed at a central portion of the insulating substrate and connection terminals provided at both ends of the PTC resistor.

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