JPH0927071A - Canned drink induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a heating time and prevent can burning due to local heating by equally heating the whole canned drink which is long in axial length when the canned drink is heated. SOLUTION: On a heat coil base 2 which is formed in an arcuate plate shape along the cylindrical can wall of the canned drink 1, a main heat coil 3 and an auxiliary heat coil 4 are arranged adjacently in the axial length direction of the canned drink 1. When the axial length of the canned drink 1 which is heated is small as shown in (a), a high-frequency current is supplied to only the main heat coil 3 to heat the canned drink. When the axial length of the canned drink 1 is long as shown in (b), the high-frequency current is supplied to the main heat coil 3 and auxiliary heat coil 4 to heat the canned drink 1.

Description

Detailed Description of the Invention

[0001]

The present invention relates to, for example, canned coffee,
The present invention relates to a canned beverage induction heating device that instantly heats a canned beverage at the time of sale in an automatic vending machine for canned beverages such as canned tea.

[0002]

2. Description of the Related Art Conventionally, there has been proposed an automatic vending machine for instantly heating a canned beverage stored at a low temperature, room temperature or in a preheated state by an induction heating device for sale. . FIG. 6 is an explanatory view of a conventional canned beverage induction heating device. In FIG. 6, 1 is a canned beverage such as canned coffee or tea, 2 is a heating coil support, and L is a heating coil.

A canned beverage 1 is provided with a heating coil support 2 having an arc plate shape.
A high-frequency current is passed through the heating coil L provided on the surface of the cylindrical can wall of the above. At that time, an eddy current flows in the canned beverage 1 due to the high-frequency magnetic field generated from the heating coil L, and Joule heat is generated to heat the canned beverage 1.

In such a canned beverage induction heating device,
When the heating coil L is made longer than the axial length of the canned beverage 1, the joints at both ends of the can have higher resistance than the side wall of the can, and the high frequency magnetic fields from the inner and outer coil portions at both ends of the can cause Since it concentrates on both ends, the Joule heat generated at both ends of the can becomes large. As a result, can burning may occur at both ends of the can, so the dimension of the heating coil L is made shorter than the axial length of the can beverage 1.

Prior art documents relating to such a canned beverage induction heating device include, for example, Japanese Utility Model Laid-Open No. 1-64776 and Japanese Patent Laid-Open No. 31-21593 (G07F 11/70).

[0006]

However, in the prior art described above, when a plurality of types of canned beverages having different axial lengths are to be heated by one heating coil L, the canned beverage having a long axial length is heated. It takes a long time, and it is difficult to perform uniform heating, and there is a problem that burning of a can occurs due to local heating.

That is, there are a plurality of types of canned beverages having different axial lengths, as illustrated in FIG. In addition,
In FIG. 7, the can length is reversed between the can types of 250 g and 350 g, but the can thickness of 350 g is 250 g.
It is because it is thicker than the one, and the length is shortened accordingly.

When a plurality of kinds of canned beverages having different axial lengths are to be heated by one heating coil L, the length of the heating coil L is shorter than the axial length of the canned beverage as described above. Due to the necessity, it will be shorter than the axial length of the shortest canned beverage. As a result, as shown in FIG. 6 (b), when heating the canned beverage 1 having a long axial length, the can is more likely to protrude from the heating coil L, and therefore the heating coil L can directly heat less. It takes a while to heat. Further, since it is difficult to uniformly heat, if the output of the heating coil is increased in order to shorten the heating time, can burning due to local heating occurs.

The present invention solves such problems,
Even for canned drinks with a long axial length, it does not take a long time to heat, and it is possible to uniformly heat the entire canned drink,
It is an object of the present invention to provide a canned beverage induction heating device that does not cause canning due to local heating.

[0010]

In order to solve the above problems, in a canned beverage induction heating device of the present invention, a main heating coil formed along the axial direction of a canned beverage and adjacent to the main heating coil. If the axial length of the canned beverage to be heated is small, the high-frequency current is passed only to the main heating coil, and if the axial length of the canned beverage to be heated is large, then the main heating coil is used. The auxiliary heating coil and the switching means for switching the circuit so that a high-frequency current flows are provided.

Further, it is provided with means for detecting the axial length dimension of the canned beverage to be heated, and the switching means is automatically switched based on the output thereof.

[0012]

When the axial length of the canned beverage to be heated is large, the circuit is switched so that a high-frequency current is passed between the main heating coil and the auxiliary heating coil. Therefore, the portion of the can protruding from the main heating coil is It can be heated by an auxiliary heating coil. As a result, the whole canned beverage can be heated uniformly, the heating time is shortened, and the occurrence of can burning does not occur.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of the first embodiment, FIG. 1 (a) shows a case of heating a canned beverage having a short axial length, and FIG. 1 (b) shows a long axial length. The case where the canned beverage is being heated is shown. Reference numerals correspond to those of FIG. 6, 3 is a main heating coil, and 4 is an auxiliary heating coil.

The main heating coil 3 is formed in a spiral shape on the surface of the heating coil support 2 in a range slightly shorter than the axial length of the canned beverage 1 having a short axial length among the canned beverages to be heated. Further, the auxiliary heating coil 4 is formed in a spiral shape so as to correspond to a portion of the canned beverage 1 that protrudes from the main heating coil 3 when heating the canned beverage 1 having a long axial length. When heating the canned beverage 1 having a short axial length as in the case of FIG. 1A, high-frequency power is applied between the terminals a and b to heat only the main heating coil 3. Further, as in the case of FIG. 1B, when heating the canned beverage 1 having a long axial length, high frequency power is applied between the terminals a and c so that both the main heating coil 3 and the auxiliary heating coil 4 are heated. To heat.

FIG. 2 is a diagram showing the outline of the second embodiment. The reference numerals correspond to those in FIG. The main heating coil 3 is formed on the surface of the heating coil support 2 in a spiral shape in a range slightly shorter than the axial length of the canned beverage 1 having a short axial length in the canned beverage to be heated. In addition, the auxiliary heating coil 4
When the canned beverage 1 having a long axial length is heated continuously on the outer peripheral side of the main heating coil 3, both ends of the canned beverage 1 are formed in a spiral shape so as to correspond to the portions protruding from the main heating coil 3. There is. When heating the canned beverage 1 having a short axial length, as in the case of FIG. 2A, high-frequency power is applied between the terminals a and b to heat only the main heating coil 3. FIG.
When heating the canned beverage 1 having a long axial length, as in the case of (b), high-frequency power is applied between the terminals a and c to perform heating by both the main heating coil 3 and the auxiliary heating coil 4. .

FIG. 3 is an electric circuit diagram of the induction heating device. Reference numerals 3 and 4 correspond to those in FIG. 1, 5 is an AC power supply, 6 is a rectifier circuit, 7 is a relay contact, 8 is an IGBT (insulated gate bipolar transistor), 9 is a can shape identifying circuit, and 10 is Induction heating control circuit, 11 is a drive circuit, 12 is a temperature sensor, and 13 is a current transformer. By turning on and off the IGBT 8, a large high-frequency current flows through the main heating coil 3 and the auxiliary heating coil 4 that form a resonance circuit together with the resonance capacitor C, and a high-frequency magnetic field is generated. Due to the high-frequency magnetic field, an eddy current flows in the can of the canned beverage 1 to generate Joule heat, and the canned beverage 1 is heated.

The can shape identifying circuit 9 is provided, for example, as shown in FIG. 4, at a position facing both ends of the canned beverage 1 when the canned beverage 1 having a long axial length is placed on the heating coil support 2. 1
The axial length dimension of the canned beverage 1 is identified based on the on / off states of the can detection switch 14 and the second can detection switch 15. That is, the first can detection switch 14 is turned on when the base end of the can beverage 1 comes into contact, and the second can detection switch 15 is turned on when the tip of the can beverage 1 having a long axial length comes into contact. On the other hand, when the canned beverage 1 having a short axial length is placed on the heating coil support 2,
The first can detection switch 14 turns on, but the second can detection switch 15 does not turn on because the tip of the canned beverage 1 does not reach the second can detection switch 15.

The induction heating control circuit 10 has a CPU (central processing unit), and switches the relay contact 7 based on the identification result of the can shape identification circuit 9. That is, when the second can detection switch 15 is not turned on even though the first can detection switch 14 is turned on, the relay contact 7 is switched to the contact b side and only the main heating coil 3 is charged. To do. On the other hand, when both the first can detection switch 14 and the second can detection switch 15 are turned on, the relay contact 7 is switched to the contact c side to charge both the main heating coil 3 and the auxiliary heating coil 4. .

Relay contact 7 by induction heating control circuit 10
The switching control is performed by a circuit as shown in FIG. 5, for example. That is, the states of the first can detection switch 14 and the second can detection switch 15 are detected by the CPU 16, and based on the result, the energization / de-energization of the relay coil 17 is controlled to switch the relay contact 7.

In addition to the switching control of the relay contact 7 as described above, the induction heating control circuit 10 also outputs an oscillation signal to the drive circuit 11 to control ON / OFF of the IGBT 8. When the IGBT 8 is turned on and off once at a certain time point, a large pulse current flows through the main heating coil 3 and the auxiliary heating coil 4 due to the resonance action of the main heating coil 3, the auxiliary heating coil 4 and the resonance capacitor C. After that, it detects that the voltage across the main heating coil 3 and the auxiliary heating coil 4 has dropped to 0, and outputs the next oscillation signal to the drive circuit 11. By repeating such an operation, a pulsed high frequency current is passed through the main heating coil 3 and the auxiliary heating coil 4.

On the other hand, the temperature sensor 12 detects the temperature of the canned beverage 1, and when the value reaches a predetermined value, the output of the oscillation signal is stopped. Also, the current transformer 13
Detects the circuit input current and stops the oscillation signal even when an abnormality such as a short circuit occurs and an overcurrent flows.

The drive circuit 11 is the induction heating control circuit 1
The oscillation signal output from 0 is amplified and given to the gate of the IGBT 8 to perform on / off control.

In the above embodiment, the main heating coil 3,
The connection of the auxiliary heating coil 4 was switched by automatically switching the relay contact 7 on the basis of the detection results of the first can detecting switch 14 and the second can detecting switch 15, but it is manually switched by the switch. You may do it. Further, although only one auxiliary heating coil 4 is provided to heat a plurality of types of canned beverages, the auxiliary heating coil 4
By providing two or more and switching between them, it is possible to efficiently heat many types of canned beverages.

[0024]

As described above, according to the canned beverage induction heating device of the present invention, even a canned beverage having a long axial length does not take a long time to be heated, and the entire canned beverage can be uniformly heated. The burning of cans due to local heating does not occur.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a first embodiment.

FIG. 2 is a diagram showing an outline of a second embodiment.

FIG. 3 is an electric circuit diagram of the induction heating device.

FIG. 4 is a diagram showing an example of a can shape identifying method.

FIG. 5 is a diagram showing an example of a can shape identifying circuit.

FIG. 6 is an explanatory view of a conventional canned beverage induction heating device.

FIG. 7 is a table showing can lengths.

[Explanation of symbols]

 1 Can Beverage 2 Heating Coil Support 3 Main Heating Coil 4 Auxiliary Heating Coil 5 AC Power Supply 6 Rectifier Circuit 7 Relay Contact 8 IGBT 9 Can Shape Identification Circuit 10 Induction Heating Control Circuit 11 Drive Circuit 12 Temperature Sensor 13 Current Transformer 14 1st Can detection switch 15 second can detection switch 16 CPU 17 relay coil L heating coil C resonance capacitor

Claims (2)

[Claims] 1. A main heating coil formed along the axial direction of a canned beverage, an auxiliary heating coil arranged adjacent to the main heating coil, and when the axial length of the canned beverage to be heated is small, A high-frequency current is supplied only to the main heating coil, and when the axial length of the canned beverage to be heated is large, the main heating coil and the auxiliary heating coil are equipped with switching means for switching the circuit so as to flow the high-frequency current. A canned beverage induction heating device characterized by: 2. An induction heating apparatus for canned beverage according to claim 1, further comprising means for detecting an axial length dimension of the canned beverage to be heated, and the switching means is automatically switched based on the output thereof. .