JP2008108595A - Food heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a food heating apparatus capable of accurately heating food contained in a case to a preset temperature. <P>SOLUTION: The food heating apparatus which has a storage tube 13 for storing a bottled drink X and a temperature measurement unit 14 for measuring the temperature of the outer surface of a plastic bottle containing the bottled drink X stored in the storage tube 13 heats the bottled drink X stored in the storage tube 13 to the preset temperature using a microwave. Further, the food heating apparatus includes a storage tube temperature sensor 16 for measuring the atmospheric temperature in the storage tube 13, a temperature calculation means for calculating a heating stop temperature on the basis of the atmospheric temperature in the storage tube 13 which is measured prior to the heating of the bottled drink X and the preset temperature, and a controller which stops the heating of the bottled drink X when the temperature of the outer surface of the plastic bottle which is measured during the heating of the bottled drink X reaches the heating stop temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a food heating apparatus that heats food contained in a bottle-shaped container such as a bottled beverage or a plastic bottle beverage.

  Generally, when heating foods in containers such as bottled beverages and plastic bottled beverages, these foods can be stored in a showcase and heated, or stored in a vending machine and heated. Like to sell.

  However, such showcases and vending machines are not always effective heating means in terms of energy efficiency because foods stored or stored are always heated and stored. In addition, long-time high-temperature heat storage causes deterioration of food quality, and there is a problem in that food is discarded at an early stage or the expiry date is shortened.

For such problems, in a vending machine equipped with a food heating device using microwaves as a heating means, the food in the container carried out from the storage unit provided at the upper part of the vending machine main body has a gently inclined portion. While being rolled, while being conveyed to the take-out part provided in the lower part of the vending machine main body, what was heated to preset temperature with a microwave is known (for example, refer patent document 1).
Japanese Patent Laid-Open No. 10-275273

  In the conventional food heating apparatus, since it is difficult to measure the temperature of the food in the container being heated in real time, the temperature of the outer surface of the container is measured in order to heat the food in the container to the set temperature.

  However, since the heat of the food in the container is transferred to the inner surface of the container and the temperature at which heat is conducted from the inner surface of the container to the outer surface of the container is measured, the measured temperature of the outer surface of the container is lower than the temperature of the food in the container. In addition, even when the temperature of the food in the container is the same, the measured temperature of the outer surface of the container varies depending on the temperature in the microwave irradiation chamber, so it is difficult to heat the food in the container to the set temperature based on the temperature of the outer surface of the container. There was a problem that.

  This invention is made | formed in view of the said problem, The place made into the objective is to provide the foodstuff heating apparatus which can heat the foodstuff in a container to preset temperature accurately.

  In order to achieve the above-mentioned object, the present invention comprises a storage unit in which food in a container is stored, and a temperature measuring means for measuring the temperature of the container outer surface of the food stored in the storage unit, and is stored in the storage unit. In the food heating apparatus for heating the food in the container to the set temperature by the microwave, the temperature measuring means has an air temperature measuring means for measuring the air temperature in the storage unit, and is measured by the air temperature measuring means before the food in the container is heated. Calculation means for calculating the heating stop temperature based on the temperature in the storage unit and the set temperature, and the temperature of the outer surface of the container measured by the temperature measuring means during the heating of the food in the container to the heating stop temperature calculated by the calculation means When it comes to, the food heating apparatus provided with the heating control means which stops the heating of the foodstuffs in a container is proposed.

  According to this food heating apparatus, when the temperature of the outer surface of the container measured during the heating of the food in the container reaches the heating stop temperature, the heating of the food in the container is stopped.

  Here, the heat of the food in the container is transferred to the inner surface of the container by convection, etc., and is conducted from the inner surface of the container to the outer surface of the container. Obtain a relational expression between the temperature inside the storage unit before heating, the temperature of the outer surface of the container when the heating is stopped, and the temperature of the food in the container after the heating is stopped by experiments, etc. By substituting the measured temperature in the storage unit and the set temperature of the food, the temperature of the outer surface of the container when heating is stopped when the temperature of the food in the container after heating stops reaches the set temperature, that is, the heating stop temperature is calculated. can do.

  According to the food heating apparatus of the present invention, a relational expression between the temperature in the storage unit before heating, the temperature of the outer surface of the container when heating is stopped, and the temperature of the food in the container after stopping heating is obtained in advance by experiments or the like. By substituting the temperature in the storage unit measured before heating the food in the container and the set temperature of the food into the relational expression, the temperature of the food in the container after the heating stops becomes the set temperature. Since the temperature of the outer surface of the container, that is, the heating stop temperature can be calculated, by stopping the heating of the food in the container when the temperature of the outer surface of the container measured during the heating of the containered food reaches the heating stop temperature, The temperature change of the outer surface of the container due to the temperature in the storage unit before heating can be reflected in the heating time, and the food in the container can be heated to the set temperature with high accuracy.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a side view for explaining a state in which a plastic bottle drink is stored in a food heating device, and FIG. 2 is a diagram of the food heating device shown in FIG. FIG. 3 is a top view of the food heating apparatus shown in FIG. 2, FIG. 4 is an enlarged cross-sectional view of the pipe and the temperature measuring unit shown in FIG. 1, and FIG. 5 is a heating view. It is a figure which shows the result of the experiment which measures the temperature in the front storage cylinder, the temperature of the PET bottle outer surface at the time of a heating stop, and the temperature of the drink in the PET bottle after a heating stop. In addition, in the following description, it demonstrates using the plastic bottle drink X as a foodstuff in a container except the case where it specifies clearly.

  As shown in FIGS. 1, 2, and 3, the food heating apparatus 10 includes a heater 11, a waveguide 12, a storage cylinder 13 (microwave irradiation chamber) that is a storage unit, and temperature measurement that is a temperature measurement unit. A unit 14, a pipe 15, and a storage cylinder temperature sensor 16 are provided.

  The heater 11 is a well-known magnetron, and generates a microwave by electric power supplied from a power source (not shown) and emits it from the antenna 11a.

  The waveguide 12 opens a part of the upper plate surface 12 a and is connected to the storage cylinder 13, and propagates the microwave emitted from the heater 11 in the direction of the cylinder 13.

  The storage cylinder 13 has a cylindrical shape with an upper surface and a lower surface opened, and the lower surface opening is connected to the waveguide 12. Further, an upper lid 13a is provided at the upper opening of the storage cylinder 13 so as to be freely opened and closed. By opening and closing the upper lid 13a, the plastic bottle drink X can be stored from the upper opening, and the storage cylinder 13 can be made microscopic. The wave is prevented from leaking. In this embodiment, it is stored in the storage cylinder 13 from the side of the spout X2 of the plastic bottle beverage X, that is, with the body portion X3 of the plastic bottle beverage X facing up. In the present embodiment, the storage cylinder 13 has a cylindrical shape, but is not limited thereto, and may have a shape other than a cylinder, for example, an ellipse or a polygon.

  The hole 12b is provided by opening a part of the upper plate surface 12a of the waveguide 12, and the antenna 11a of the heater 11 (magnetron) is inserted therein.

  The stub 12c is provided on the inner side of the upper plate surface 12a, and functions as a matching unit for causing the microwaves emitted from the antenna 11a to efficiently enter the plastic bottle beverage X.

  The storage cylinder temperature sensor 16 is composed of a known thermistor, and is provided inside the vicinity of the upper surface opening of the storage cylinder 13 to measure the temperature in the storage cylinder 13.

  As shown in FIG. 4, the temperature measurement unit 14 includes a known infrared radiation temperature sensor 14 a, a case 14 b, and a screw 14 c, and measures the temperature of the squeezed portion X1 of the plastic bottle beverage X stored in the tube 13. is doing. Here, since the plastic bottle drink X is thrown into the storage cylinder 13 from the spout X2 side, the air layer in the plastic bottle exists on the bottom surface of the plastic bottle and does not exist in the squeezed portion X1. In general, the narrowed portion X1 does not have a label covering the plastic bottle or has no gap (air layer) even if it exists. Furthermore, the thickness of the narrowed portion X1 is not thicker than other portions such as the bottom surface and the cap. Therefore, by measuring the temperature of the squeezed portion X1 of the plastic bottle beverage X, it is possible to accurately measure the temperature of the outer surface of the plastic bottle as compared with other portions.

  The infrared radiation temperature sensor 14a can change the measurement angle φ, receives infrared radiation emitted from the measurement range A of the aperture X1, and outputs a temperature signal to a control unit (not shown). .

  The case 14b covers the infrared radiation temperature sensor 14a and is attached to the pipe 15 with a screw 14c. As described above, the infrared radiation temperature sensor 14a is covered with the case 14b, so that the influence of infrared rays other than the measurement range A can be reduced, and the case 14b is attached to the pipe 15 with the screw 14c, so that the attachment / detachment is facilitated.

  Further, when the case 14 b is attached to the pipe 15, the infrared radiation temperature sensor 14 a is disposed on the central axis C of the pipe 15. Thereby, the measurement angle φ can be maximized.

  The pipe 15 is provided in the horizontal direction of the plastic bottle beverage X stored in the storage cylinder 13, and communicates the storage cylinder 13 with the temperature measurement unit 14. Thereby, since the temperature of the throttle part X1 is measured from the horizontal direction of the plastic bottle drink X, the measurement range A becomes an elliptical shape.

  In the food heating apparatus 10 configured as described above, the plastic bottle beverage X is stored in the storage cylinder 13 from the side of the spout X2 of the plastic bottle beverage X, that is, with the body portion X3 of the plastic bottle beverage X facing up, and a control unit (not shown). By irradiating microwaves from the antenna 11a to the narrowed portion X1 of the plastic bottle beverage X, it becomes possible to efficiently guide the convection of the beverage in the plastic bottle, and the plastic bottle beverage X can be heated uniformly. In this embodiment, one heater 11 and one waveguide 12 are provided. However, the present invention is not limited to this, and a plurality of heaters 11 and waveguides 12 may be provided. Thereby, a microwave is irradiated to the plastic bottle drink X from a plurality of directions, and it becomes possible to heat in a shorter time. In the present embodiment, the plastic bottle drink X is stored in the storage cylinder 13 from the spout X2 side, but is not limited thereto, and is stored in the storage cylinder 13 from the bottom direction to measure the temperature of the throttle portion X1. You may do it.

  Here, when the temperature of the outer surface of the PET bottle measured by the infrared radiation temperature sensor 14a during the heating of the PET bottle beverage X reaches a predetermined constant temperature, the control unit (not shown) stops heating. FIG. 5 shows the results of an experiment for measuring the temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the plastic bottle when heating is stopped, and the temperature of the beverage in the PET bottle after heating is stopped.

  As shown in FIG. 5, the temperature (y) of the beverage in the PET bottle after stopping the heating does not depend on the predetermined constant temperature on the outer surface of the PET bottle, and the temperature of the outer surface of the PET bottle when the heating is stopped and the storage cylinder before heating. 13 changes almost linearly in proportion to the difference (x) from the temperature in the air and can be expressed by the following equation (1).

y = ax + b (1)
However, a and b are constants. Therefore, the heat of the beverage in the PET bottle is transferred to the inner surface of the PET bottle by convection, and is conducted from the inner surface of the PET bottle to the outer surface of the PET bottle. Since the amount of heat released or the amount of heat absorbed differs, the relationship between the temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the PET bottle when heating is stopped, and the temperature of the beverage in the PET bottle after heating is stopped by experiment or the like. ) In advance, and substituting the temperature in the storage cylinder 13 measured by the storage cylinder temperature sensor 16 before heating the plastic bottle beverage X and the set temperature of the beverage into the relational expression (1) to stop heating. The temperature of the outer surface of the PET bottle when heating is stopped when the temperature of the beverage in the later PET bottle reaches the set temperature, that is, the heating stop temperature can be calculated.

  Thus, according to the present embodiment, the relationship between the temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the PET bottle when heating is stopped, and the temperature of the beverage in the PET bottle after heating is stopped by experiments or the like ( 1) is obtained in advance, and heating is performed by substituting the temperature in the storage cylinder 13 measured by the storage cylinder temperature sensor 16 and the set temperature of the beverage before the heating of the plastic bottle beverage X into the relational expression (1). Since the temperature of the outer surface of the PET bottle when the heating is stopped when the temperature of the beverage in the PET bottle after the stop reaches the set temperature, that is, the heating stop temperature can be calculated, it was measured during the heating of the PET bottle beverage X. When the temperature of the outer surface of the PET bottle reaches the heating stop temperature, heating of the PET bottle beverage X is stopped, thereby heating the temperature change of the outer surface of the PET bottle due to the temperature in the storage cylinder 13 before heating. Can reflect between, it is possible to heat the beverage in the PET bottle to accurately set temperature.

  6 to 8 show a second embodiment of the present invention. FIG. 6 is a top view of the food heating apparatus, FIG. 7 is the temperature inside the storage cylinder before heating, the temperature of the outer surface of the PET bottle when heating is stopped, FIG. 8 is a diagram showing a result of an experiment for measuring the temperature of the beverage in the PET bottle after stopping the heating, and FIG. 8 is a diagram showing a relationship between the y-intercept of the temperature of the beverage in the PET bottle after stopping the heating and the outside air temperature. .

  The difference between the second embodiment and the first embodiment is that the temperature outside the food heating device 10 is also measured in addition to the temperature inside the storage cylinder 13. Note that the same components as those of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  That is, as shown in FIG. 6, an external temperature sensor 17 composed of a known thermistor is provided outside the storage cylinder 13 to measure the temperature outside the food heating device 10. In the present embodiment, the external temperature sensor 17 is provided outside the storage cylinder 13. However, the present invention is not limited to this, and the external temperature sensor 17 may be provided anywhere as long as the temperature outside the food heating device 10 can be measured.

  Here, when the temperature of the outer surface of the PET bottle measured by the infrared radiation temperature sensor 14a during the heating of the PET bottle beverage X reaches a predetermined constant temperature, the control unit (not shown) stops heating. For each outside temperature measured by the external temperature sensor 17 before heating, the temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the plastic bottle when heating is stopped, and the temperature of the beverage in the PET bottle after stopping heating are measured. The result of the experiment is shown in FIG.

  As shown in FIG. 7, the temperature (y) of the beverage in the PET bottle after stopping the heating, which can be expressed by the above formula (1), does not depend on the predetermined constant temperature on the outer surface of the PET bottle, and the pet when the heating is stopped It is proportional to the difference (x) between the temperature of the bottle outer surface and the temperature in the storage cylinder 13 before heating, the slope (a) is the same regardless of the outside temperature, and the y intercept (b) is different for each outside temperature. It is changing linearly. The slope (a) was almost constant regardless of the beverage capacity.

  Moreover, it shows in FIG. 8 which shows the relationship between the y intercept of the temperature (y) of the drink in the PET bottle after the heating stop for every external temperature, and external temperature. Thus, the y-intercept (bn) changes in proportion to the outside air temperature (z) for each beverage volume (n) and can be expressed by the following equation (2).

bn = cnz + dn (2)
However, cn and dn are constants that differ for each beverage volume (n), and n is a positive integer. Therefore, the temperature (yn) of the beverage in the plastic bottle after stopping the heating for each beverage volume (n) is expressed by the formula ( It can be expressed by the following formula (3) from 1) and formula (2).

yn = ax + cnz + dn (3)
However, cn and dn are different constants for each beverage capacity (n), and n is a positive integer. Therefore, the temperature outside the food heating device 10 before heating affects the temperature of the beverage in the plastic bottle after heating is stopped. Therefore, the relational expression (3) between the outside air temperature before heating, the inside air temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the plastic bottle when the heating is stopped, and the temperature of the beverage in the PET bottle after the heating is stopped. Is obtained in advance, and the relationship between the outside temperature measured by the external temperature sensor 17 before the PET bottle beverage X is heated and the storage tube measured by the storage tube temperature sensor 16 before the PET bottle beverage X is heated. By substituting the air temperature in 13 and the set temperature of the beverage, the temperature of the outer surface of the PET bottle when the heating is stopped when the temperature of the beverage in the PET bottle after the heating stops becomes the set temperature, that is, the heating stop temperature. The degree can be calculated.

  In this embodiment, the temperature outside the food heating apparatus was measured before the PET bottle beverage X was heated in the experiment. However, the present invention is not limited to this, and is hardly affected by the heating by the microwave. You may make it measure. Moreover, although relational expression (3) was calculated | required for every capacity | capacitance of the drink, it is not limited to this, For example, you may make it obtain | require a relational expression for every kind or shape of a drink, or these combinations.

  Thus, according to the present embodiment, the outside temperature before heating, the temperature in the storage cylinder 13 before heating, the temperature of the outer surface of the PET bottle when heating is stopped, and the beverage in the PET bottle after heating is stopped by experiments or the like. The relational expression (3) with the temperature is obtained in advance, and the relationship between the outside temperature measured by the external temperature sensor 17 before the PET bottle beverage X is heated and the storage cylinder temperature before the PET bottle drink X is heated in the relational expression (3). By substituting the temperature in the storage cylinder 13 measured by the sensor 16 and the set temperature of the beverage, the temperature of the beverage in the PET bottle after stopping the heating becomes the set temperature. Since the temperature, that is, the heating stop temperature can be calculated, when the temperature of the outer surface of the PET bottle measured during the heating of the PET bottle beverage X becomes the heating stop temperature, By stopping the heat, the temperature change of the outer surface of the PET bottle due to the outside air temperature before heating and the temperature inside the storage cylinder 13 can be reflected in the heating time, and the beverage in the PET bottle is heated to the set temperature with higher accuracy. be able to.

  FIG. 9 shows a third embodiment of the present invention, and FIG. 9 is a cross-sectional view for explaining a state before storing a plastic bottle drink in a food heating device.

  The difference between the third embodiment and the first embodiment is that a shielding plate 18 is provided in place of the storage cylinder temperature sensor 16, and the infrared radiation temperature sensor 14a measures the temperature in the storage cylinder 13. . Note that the same components as those of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

That is, as shown in FIG. 9, a Teflon (registered trademark) shielding plate 18 capable of transmitting microwaves is provided at the opening end of the waveguide 12 so as to form a wall surface in the storage cylinder 13. . The shielding plate 18 is desirably provided so as to close the open end of the waveguide 12 without any gap. The material of the shielding plate 18 is preferably Teflon (registered trademark), but may be the same material as that of the plastic bottle. In this case, the constants in the above formulas (1) to (3) and the output of the heater (magnetron) 11 are adjusted.
The infrared radiation temperature sensor 14a in the temperature measurement unit 14 receives the infrared radiation emitted from the shielding plate 18 and measures the temperature in the storage cylinder 13 before the plastic bottle drink X is stored in the storage cylinder 13. Yes. Thereby, the air temperature in the storage cylinder 13 can be measured without protruding the storage cylinder temperature sensor 16 that may be discharged by the microwave in the storage cylinder 13.

  In the present embodiment, the shielding plate 18 is provided so as to form the wall surface in the storage cylinder 13, but the present invention is not limited to this. For example, as shown in FIG. 10, the plastic bottle drink X is stored in the storage cylinder 13. Before the temperature measurement unit 14 is moved, the infrared radiation temperature sensor 14 a may receive the infrared radiation emitted from the inner wall surface of the storage cylinder 13 and measure the temperature in the storage cylinder 13.

  Thus, according to the present embodiment, in addition to the same effects as those of the first embodiment, a Teflon (which can transmit microwaves to the open end of the waveguide 12 so as to form a wall surface in the storage cylinder 13). Since a shield plate 18 made of (registered trademark) is provided and the infrared rays emitted from the shield plate 18 are received and the temperature in the storage cylinder 13 is measured before the plastic bottle drink X is stored in the storage cylinder 13, the micro Since the temperature in the storage cylinder 13 can be measured without protruding the storage cylinder temperature sensor 16 that may be discharged by waves in the storage cylinder 13, the plastic bottle beverage X can be heated safely. At the same time, the infrared radiation temperature sensor 14a can be used for both the temperature measurement on the outer surface of the plastic bottle and the temperature measurement in the storage cylinder 13.

  In addition, the structure of this invention may combine the structure of each said embodiment, or may replace a one part structure part.

  The configuration of the present invention is not limited to the above embodiments, and various modifications may be made without departing from the spirit of the present invention.

Side view explaining the state which stores a plastic bottle drink in a food heating device Sectional drawing explaining the state which stored the plastic bottle drink in the food heating apparatus shown in FIG. Top view of the food heating device shown in FIG. Enlarged sectional view of the pipe and temperature measurement unit shown in FIG. The figure which shows the result of the experiment which measures the temperature in the storage cylinder before a heating, the temperature of the outer surface of a PET bottle at the time of a heating stop, and the temperature of the drink in the PET bottle after a heating stop 6 is a top view of the food heating device. The figure which shows the result of the experiment which measures the temperature in the storage cylinder before a heating, the temperature of the outer surface of a PET bottle at the time of a heating stop, and the temperature of the drink in the PET bottle after a heating stop The figure which shows the relationship between y intercept of the temperature of the drink in the PET bottle after a heating stop, and external temperature Sectional drawing explaining the state before storing a plastic bottle drink in a food heating apparatus The top view which shows the modification of the food heating apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Food heating apparatus, 13 ... Storage cylinder, 14 ... Temperature measuring unit, 14a ... Infrared radiation temperature sensor, 16 ... Storage cylinder temperature sensor, 17 ... External temperature sensor, 18 ... Shielding board, X ... PET bottle drink.

Claims (4)

A storage unit for storing the food in the container and a temperature measuring means for measuring the temperature of the outer surface of the food stored in the storage unit are provided, and the food in the container stored in the storage unit is heated to a set temperature by the microwave. In the food heating device
The temperature measuring means has an air temperature measuring means for measuring the air temperature in the storage unit,
Calculation means for calculating a heating stop temperature based on the temperature in the storage unit measured by the temperature measurement means and the set temperature before heating the food in the container;
A heating control means for stopping the heating of the food in the container when the temperature of the outer surface of the container measured by the temperature measuring means during the heating of the food in the container reaches the heating stop temperature calculated by the calculating means. Characteristic food heating device. The temperature measuring means has an outside air temperature measuring means for measuring outside air temperature,
Based on the outside temperature measured by the outside air temperature measuring means before heating the food in the container and the temperature in the storage unit and the set temperature measured by the air temperature measuring means before the food in the container are heated. The food heating apparatus according to claim 1, further comprising means for calculating a stop temperature. The food heating according to claim 1, wherein the temperature measuring unit includes an infrared radiation temperature sensor that measures a temperature of a predetermined wall surface in the storage unit as an air temperature in the storage unit measured by the air temperature measurement unit. apparatus. The food heating apparatus according to claim 3, wherein a shielding plate capable of transmitting microwaves is provided as the predetermined wall surface.

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