JPH0719648B2 - How to heat canned food - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for heating cans of various metals used for foods and beverages in vending machines and the like, and in particular, a bar code near the joint of the can body. The present invention relates to a high-frequency induction heating method applicable to a can and the like which is displayed and is joined with a polymer adhesive.

b. Conventional technology Recently, beverages such as canned coffee and cocoa, as well as sake, have been warmed and sold automatically. Conventionally, as a heating method for canned goods in this kind of vending machine, the canned goods stored in a standby state inside the machine are heated while controlling a constant temperature of about 55 ° C. using an electric heating device.

However, if the canned goods are stored in the machine under heating for a long time by this method, the following problems occur. That is, in addition to the hygienic problem that the taste and nutritional value of the contents are deteriorated, and thermophilic bacteria grow, especially in the case of dairy products, the milk fat component separates and adheres to the inner wall of the can, which There is a problem of deterioration.

In addition, as a conventional heating method for canned food, there is a method shown in FIGS. 6 to 8. 6 is an explanatory view when the canned food 1 is heated by high frequency induction, FIG. 7 is a partial sectional view of the canned food 1, and FIG. 8 is a current distribution diagram in the can body 2 of the canned food 1.

In the figure, a can 1 containing a beverage, having a portion 3 in which a can body 2 is joined with a polymer adhesive 2a, is inserted sideways into a heating coil 4, and the can 1 is rotated. When high frequency power is supplied from the high frequency power source 5 to the heating coil 4,
A current 6 flows through the can body 2 as shown by the dotted line in FIG. Since the joint 3 is insulated by the adhesive 2a, the electric current 6
Flows concentratedly in the winding portion 7 between the can body 2 and the lid and bottom,
When an attempt is made to heat the wire in a short time by increasing the supplied power, the winding portion 7 is overheated and a part of the metal is melted, the contents flow out, and further, the portion along the joint portion 3 of the can body 2. However, there is a problem that the adhesive 2a is finally melted and the joint 3 is peeled off, and the contents are blown out.

In order to improve these problems, a heating method for canned foods and an apparatus for improving the shape of a heating coil have been proposed in Japanese Patent Laid-Open No. 58-189981. This proposal can be applied to a metal can in which a can body is joined with a polymer adhesive and can be rapidly heated.

c. Problem to be Solved by the Invention According to the above proposal, when a 250 cc beverage can is heated for 12 seconds, the temperature rise is about 20 ° C.

However, experiments have shown that 250cc of liquid can be used for 20 seconds in 20 seconds.
In order to raise the temperature by 0 ° C., it is necessary to raise the surface of the can body 2 by 230 ° C. to 250 ° C. Therefore, there is a problem that the adhesive 2a of the joint portion 3 is melted and peeled off. That is, as shown in FIG. 7, the joint portion 3 is overlapped with the can body 2 with a width of about 5 mm through the polymer adhesive 2a having a temperature of 250 ° C. to 260 ° C. When the outside of 3 is cooled by the liquid of the contents, the adhesive 2a is passed through to cool the outside, which makes it difficult to cool. Therefore, when heating was attempted in a short time, the adhesive 2a of the joint portion 3 melted and peeling occurred.

Further, even when heating with a split coil according to Japanese Patent Laid-Open No. 58-189981, even if the induced current circumventing the winding portion with the can body can be reduced, depending on the position of the can, the induced current may flow to the winding portion and the joining portion. Concentration is unavoidable, and according to the experiment, when heating the entire can to raise the temperature by 20 ° C, there is no problem when heating over 18 seconds or more, but try to heat in a short time of 18 seconds or less. Then, there is a problem that the joint is overheated and the adhesive is melted and the contents are discharged.

On the other hand, in the case of heating and selling with a vending machine, if the waiting time is long, the purchaser is irritated, and if the temperature rise is not increased by 20 ° C within 10 seconds, it is not practical.

The present invention has been made in view of the above problems, and an object of the present invention is to solve the above problems and propose a heating method for a can of canned joints that are joined by a polymer adhesive and do not separate.

d. Means for Solving the Problems In order to achieve the above object, the present invention uses a bar code displayed on the surface of the can body near the joint, and the structure of the present invention is Is joined with a polymer adhesive,
A can of which the lid and bottom are wound around the can body and filled with the contents is held in a heating coil wound in a spiral shape along the surface of the can body and in an arc state. In a heating method of high-frequency induction heating the surface, the canned product is held in the heating coil, and immediately before the can body surface is subjected to high-frequency induction heating, the canned product is rotated about the can axis so that the can body surface is The position of the displayed bar code is detected by the position detecting means and the rotation is stopped to position the joint portion on the side not facing the heating coil, and then high frequency induction heating is performed. .

e. Operation The heating method for canned foods configured as described above has the following effects.

In the heating method for canned foods configured as described above, the canned body joint portion is bonded with a polymer adhesive, and the lid and bottom are wound around the canned body to form a canned food filled with contents. The position of the bar code displayed near the joint of the can body is detected by the detecting means immediately before high-frequency induction heating is performed in a heating coil wound in a spiral shape along the surface of the can body and in an arc state. Stop the rotation of the can, position the joint of the can body on the side not facing the heating coil,
When high-frequency induction heating is performed from the surface of the can body on the side opposite to the joint part, the induction current should not be concentrated on the joint part of the can body, the lid of the can, and the winding portion of the bottom.

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

1 to 3 show an embodiment of a heating method for canned goods according to the present invention. FIG. 1 is an explanatory view of essential parts when the canned food 1 is subjected to high frequency induction heating, and FIG. 2 is II- in FIG. FIG. 3 is a sectional view taken along the line II, and FIG. 3 is a distribution diagram of the induced current in the can body 2 of the canned product 1. In the figure, the same members as those in FIGS. 6 to 8 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 1, 10 is a heating coil that approaches the lower surface of the lying canned beverage 1 and surrounds the can body 2 in a semi-circular shape, and is wound in a spiral shape. The end is connected to the high frequency power supply 14. The canned food 1 is held so that the left and right lids and the bottom portion are sandwiched by rotatable receiving members 11a and 11b, and the canned food 1 is moved in parallel to the heating position on the heating coil 10 and inserted / discharged.

On the other hand, on the surface of the can body 2, a bar code 12 as product information is usually displayed near the joint portion 3, and when the canned goods are rotated by the receiving members 11a and 11b at the heating position,
A position sensor 13 capable of detecting the position of the bar code 12 is provided on the side facing the surface of the can body opposite to the semi-arcuate heating coil 10, and the bar code 12 is detected and rotation is stopped. At times, the joint portion 3 of the can body 2 is disposed so that the position thereof is on the upper side, that is, on the side not facing the heating coil.

The canned product 1 is held by the receivers 11a and 11b, then inserted in parallel to the heating position, and received by a control drive device (not shown) until the position sensor 13 detects the position of the bar code 12 on the surface of the can body 2. Rotate the tools 11a and 11b in the same direction to move the position sensor 13
Detects the bar code 12, the receiver 11a, 11b
Stop the rotation of. After the rotation is stopped, the heating coil 10 is supplied with power from the high frequency power source 14 to heat the canned food 1 by high frequency induction to warm the contents. 15a is a temperature sensor for measuring the heating temperature of the canned product 1 in a non-contact manner, for example, a temperature measuring part of a radiation thermometer, and 15b is a temperature display part thereof.

The heating coil 10 in FIG. 2 shows the current direction at a certain moment, and the distribution of the induced current 16 in the can body 2 at this time is shown by the dotted line in FIG. From this current distribution, the current 16 is the heating coil 10
Flows directly underneath and does not flow to the joint portion 3 of the canned food 1. Therefore, the joint portion 3 is not overheated and peeled off.

During heating, the temperature of the contents of the canned food 1 is averaged, and in order to improve the heating efficiency, the canned food 1 is received in the state shown in FIG.
It is preferable to repeatedly swing the left and right sides, the upper and lower sides, or both of them while being sandwiched by.

4 and 5 show the vending machine according to the present invention, in which FIG. 4 is a flowchart thereof and FIG. 5 is a front view of the vending machine.

In the figure, a person who purchases a can of beverage contains a coin into the vending machine 20 and presses a can type selection switch 21 to convey the can 1 selected at 22 to a heating position in the machine. At this time, the time required to convey the canned food 1 is inspected at 23, and it is confirmed whether or not the cans are reliably conveyed. After the canned product 1 is conveyed to the heating position, the bar code 12 displayed on the can body 2 at 24, the position sensor 13, and a control drive device (not shown) detect the position of the bar code 12 to detect the canned product 1. The joint 3 is located on the upper side. That is, it is located on the side not facing the heating coil. Next, at 25, power is supplied to the heating coil 10 from the power supply device 14 for high frequency induction heating, which will be described later, provided inside the machine, and heating of the can body 2 is started, and at the same time, the radiation thermometer (15a, 15b) measures the temperature of the canned product 1. The temperature is measured without contact, and this is continuously or intermittently displayed on the can temperature display (temperature display) 26.

The purchaser looks at the display of the can temperature display 26, and when the temperature reaches his or her desired temperature, the can temperature selection push button switch 27
When is pressed, the supply of high-frequency power to the heating coil 10 is cut off, the can 1 is conveyed by the conveying mechanism at 28, and the take-out port 29
To discharge. If the purchaser does not press the can temperature selection push button switch 27, the can temperature is automatically heated by the can heating time timer 30 until the supply of high frequency power to the heating coil 10 is cut off, and the can temperature is increased. At about 60 ° C., the canned food is discharged to the outlet 29 as described above. To raise the temperature of canned food 1 containing 250cc of beverage (liquid) by 20 ℃, input power of 3k
It takes 20 to 25 seconds at W.

In addition, the radiation thermometer (15a, 15b) is usually used to measure the can temperature, but in order to avoid cost increase, keep the initial temperature (storage temperature) of the canned can 1 with a drink and heat it. The product of the high-frequency power supplied to the coil 10 and the heating time may be experimentally converted into a temperature and the temperature may be displayed.

FIG. 9 is a main configuration diagram of the high frequency induction heating power supply device 14. In the figure, the commercial power supply 41 is converted into a direct current by the rectifier 42 and the capacitor 43, the power is controlled by the power transistor group 44 and the controller 45, and then converted to a high frequency by the static induction type transistor group 46, and passed through the matching transformer 47. To supply high-frequency power to the heating coil 10.

Next, the test results in this example will be described below.

Metal canned coffee with a diameter of 53 mm and a height of 120 mm (250 cc
Input) for high frequency induction heating, diameter as heating coil
A 4 mm copper tube is wound 10 times in a spiral shape and along a round bar with a diameter of 60 mm, as shown in Fig. 2, is formed so as to surround the can body 2 in a semi-circular state, and the capacity is 3 kHz. , 5 kW high-frequency induction heating power supply device was used, and the test was conducted in the mounted state shown in FIG.

As a result, high-frequency power of 5 kW was supplied to the heating coil for 8 to 10 seconds, and the can temperature could be raised from 25 ° C to 45 ° C. Heating efficiency (electric power used to raise temperature / output input from power supply x 10
Although it was 0%) 69%, it is possible to further improve the efficiency by inserting an iron core into the heating coil and concentrating the magnetic flux.

The temperature distribution of the canned food was measured by applying a temperature-indicating paint to the surface of the can body. As a result, it was found that heating was performed along the shape of the heating coil as indicated by the dotted line showing the current distribution in FIG. No heat effect was seen on the canning lid and bottom winding diagrams and the can body joints.

Further, during the heating, the temperature of the canned food is displayed in a timely manner, and during the heating, the high frequency induction heating of the can body can be stopped by operating the switch means according to the displayed temperature. Can be heated for hours.

The technique of the present invention is not limited to the technique in the above-described embodiment, and may be implemented by means of another aspect having a similar function, and the technique of the present invention may be variously modified within the scope of the above configuration. Can be added. For example, it is possible to move the one positioned by the bar code in front of the heating position to the heating coil position.

g. Effect of the invention As is apparent from the above description, according to the present invention, when heating a canned product having a can body joint portion joined by a polymer adhesive, a bar code displayed on the can body surface is used. Based on the position, the joint portion is located on one side, and the spiral-shaped heating coil is brought close to and surrounds the surface on the opposite side of the can body so that high-frequency induction heating is performed. The temperature rise of the joint located at is not high,
Therefore, the adhesive does not melt even if it is rapidly heated, and the bonded portion is not peeled off. In addition, since it can be rapidly heated, it is not necessary to store it in the machine in a heated state for a long time, so that it is possible to always provide a product in a canned product that is hygienic and does not deteriorate in taste.

[Brief description of drawings]

1 to 3 show one embodiment of the heating method and device for canned goods of the present invention. FIG. 1 is an explanatory view of essential parts when high-frequency induction heating of canned goods, and FIG. 2 is II of FIG. -A sectional view taken along the line II, Fig. 3 is a distribution diagram of the induced current in the can body of the can, Fig. 4 is a flow chart of the vending machine of the present invention, and Fig. 5 is a front view of the vending machine. FIGS. 6 to 8 show a conventional heating method for canned goods. FIG. 6 is an explanatory view of high-frequency induction heating of canned goods, FIG. 7 is a partial sectional view of the same, and FIG. 8 is the same. FIG. 9 is a main configuration diagram of a high-frequency induction heating power supply device, and FIG. 9 is a distribution diagram of induced current in a can body of a can. 1 ... canned, 2 ... can body, 3 ... joint, 10 ... heating coil, 12 ... bar code, 13 ... position sensor, 15a ... temperature sensor, 15b ... temperature display, 26 ... … Can temperature display, 27… Can temperature selection push button switch.

Claims (1)

[Claims] 1. A can body joint part is joined by a polymer adhesive, and a lid and a bottom are wound around the can body so that a can filled with contents is placed along the surface of the can body. In a heating method of holding in a heating coil wound in a spiral shape and in an arc state and high-frequency induction heating the surface of the can body, the can is held in the heating coil and high-frequency induction heating of the surface of the can body. Immediately before, the canned product is rotated about the can axis, the position of the bar code displayed on the surface of the can body is detected by the position detection means, and the rotation is stopped, so that the joint portion is Position it on the side that does not face the heating coil,
A heating method for canned foods, which is characterized by high-frequency induction heating thereafter.