JPS6237514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rapid heating device for metal cans in vending machines for canned beverages, and more specifically, to a device for rapidly heating metal cans in vending machines for canned beverages, etc. The present invention relates to an induction coil device for rapid heating that can be applied to metal cans.

(Prior Art) In recent years, it has become common to heat beverages such as canned coffee and cocoa or canned Japanese sake and sell them automatically. Conventionally, cans in this type of vending machine have been heated by controlling the storage atmosphere or bath at a constant temperature of about 55°C.

The method of keeping all the cans stored in the vending machine at the above temperature has the advantage of being able to supply hot beverage cans continuously without waiting time, but it also has the advantage that the beverages are kept at high temperatures for a long time. Failures are likely to occur. That is, the taste and nutritional value are likely to deteriorate, and hygienic problems due to the proliferation of thermophilic bacteria and accelerated corrosion of cans are likely to occur.

In order to avoid the above-mentioned problems, so-called instant heating systems have recently been introduced in which the purchaser inserts a coin and presses an item selection button to start heating individual cans. A vending machine appeared. In order to heat the can to the desired temperature within as short a time as possible, high-frequency induction heating, which is a heating method with high energy density and efficiency, is usually used for this purpose. In the past, cans heated by this method were generally made of tin plated steel plate and were soldered together in a cylindrical shape.

Therefore, in order to perform high-frequency induction heating on the metal can, as shown in FIG. Simply passing a high frequency current through 101 was sufficient to achieve the purpose. This is because the side wall joint 104 of the metal can is joined with solder that is a good electrical conductor, so a single induced current induced in the can body, that is, the body wall, is distributed almost uniformly along the outer periphery of the can body. Due to the fact that it can flow.

However, recently, an electrically insulating polymeric adhesive 201 made of TFS (tain-free steel: electrolytic chromic acid treated steel sheet) or the like as shown in FIG. Side wall joint portion 205 formed by overlapping and bonding the end portions 203
A metal can 200 having a body wall portion 204 having a body wall portion 204 has come to be used. When an attempt was made to heat this metal can 200 with the solenoid coil 101, not only was the heating efficiency unusually low, but there was also an abnormality in the T-shaped overlap between the side wall joint 205 and the seamed parts of the can bottom and lid. There was a problem that burnout occurred due to overheating, and the adhesive part peeled off.

(Problems to be Solved by the Invention) According to the present invention, the side wall joints of the body wall are formed by joining with a polymer adhesive, and the bottom and the lid are secured to the body wall. High-frequency induction heating is applied to a sealed metal can filled with the contents of An object of the present invention is to provide a coil device suitable for use in an instant heating type canned beverage vending machine.

(Means for Solving the Problems) The high-frequency induction heating coil device for heating metal cans of the present invention is formed by joining the side wall joints of the body wall with a polymer adhesive, and the bottom A high-frequency induction heating coil device for heating a metal can filled with contents and sealed with a lid wound around the body wall, the device being close to the outer surface of the body wall. A plurality of annular coil elements are formed to surround the body wall and are arranged relatively close to each other in the height direction of the metal can, and each of the annular coil elements is It is characterized in that the coil elements are connected so that the currents flowing through them are in opposite phases.

(Function) The annular coil elements are arranged relatively close to each other in the height direction of the metal can so as to surround the body wall of the metal can. On the other hand, the side wall joint of the body wall is formed by joining with a polymer adhesive, so it is electrically insulated against the circumferential induced current induced in the body wall by the annular coil element. It has become a sexual thing. Therefore, the circumferential induced current is interrupted near the side wall joint, making it difficult to form a closed circuit that goes around the body wall.

However, since the plurality of toroidal coil elements are arranged relatively close to each other in the height direction and are connected so that the current flowing through each adjacent toroidal coil element is in opposite phase, the first toroidal coil element First base
The circumferential induced current of is based on the adjacent second annular coil element in the vicinity of both sides of the sidewall joint,
It is easy to merge with the second circumferential induced current flowing in the opposite direction to the first circumferential induced current. Therefore, most of the induced current turns around near both sides of the electrically insulating sidewall joint and flows smoothly, and only a portion of the circumferential induced current due to the top and bottom annular coil elements
The part where the side wall joint part and the seaming part overlap in a T-shape (hereinafter referred to as the T-shape part; 208, 209 in Fig. 5)
However, since the amount of current is very small, there is no risk of abnormal overheating in the T-shaped portion.

Therefore, in combination with the fact that the annular coil element is disposed close to the outer surface of the body wall, a relatively high heating effect can be obtained, and there is also a risk that the T-shaped part will burn out and the adhesive part will peel off. do not have.

On the other hand, when using the conventional solenoid coil 101, the induced current 207 induced in the body wall 204
As shown in FIG. 5, the liquid tends to flow circumferentially along the outer periphery of the body wall 204 in parallel with the solenoid coil 101, but the polymer adhesive 201 (FIG. 4), which is an electrical insulator, intervenes. The flow is obstructed by the sidewall joints 205.

By the way, the bottom and lid are seamed to form the body wall part 2.
04, but the seaming parts 215, 216
To ensure airtightness, an electrically insulating rubber sealant (not shown) is interposed between the two. Therefore, electrical continuity between the barrel wall and the lid and bottom is only achieved through point contact due to breakage of the sealing material and paint film during processing. An electric circuit is formed by diverting the total induced current 207 to the T-shaped portions 208, 209 with high electrical resistance for point contact. As a result, the amount of heat generated in the T-shaped portions 208 and 209 increases, causing burnout, and the large electrical resistance reduces the total amount of current flowing, resulting in an abnormally low heating efficiency.

(Example) As shown in Fig. 1 and Fig. 2, the inner diameter is 2 metal cans.
An insulating cylindrical body 210 that is 5 mm larger than 00
8 annular coil elements 211a, 211b, 2
11c, 211d, 211e, 211f, 211
g, 211h at a pitch of 10 mm, that is, wound relatively close to each other in the height direction at equal intervals, and then wind coil elements adjacent to each other (for example, 211a and 211
b) were connected so that the current flowing through them was in opposite phase. Each annular coil element 211 is a copper wire with a diameter of 3 mm wound twice (in the figure, it is wound once for clarity), and eight of these are connected in series to a high frequency power source 212.

The current distribution of the induced current 214 induced by the coil 211 in the body wall portion 204 of the metal can 200 bonded by the polymer adhesive 201 was determined from the results obtained by applying a temperature-indicating paint and observing it. It was as shown in the figure. In other words, the induced current that detours to the T-shaped portions 208, 209 of the winding portions 215, 216 with the lid and bottom is only a portion of the current induced by the annular coil elements 211a, 211h closest to the lid and bottom. , other induced currents 214
All of the toroidal coil elements (for example, 211
b and 211c), which flows in the opposite direction.

A 250ml coffee can (using a polymer bonded metal can 200) is placed in the coil 211,
In a heating experiment using a 3kW high-frequency power source, the heating efficiency was up to 60%. The coil 211 is made by winding it around the cylindrical body 210 while forming an axial folded part 211x at the connecting part of each annular coil element, so it has a predetermined size to match the metal can 200. can be easily produced.

A magnetic core made of a ferromagnetic material may be used in combination with the coil 211. High frequency power source is controlled by rectifier etc.
For frequencies below 10kHz, laminated silicon steel plates may be used as the magnetic core. Also, the frequency
If the frequency is below 500kHz, use Mn-Zn as the magnetic core.
A type of ferrite magnetic core is effective. However, it goes without saying that impedance matching with the high-frequency power source may be achieved by increasing or decreasing the number of windings depending on the frequency, or by switching connections in series or parallel.

(Effects of the Invention) The high frequency induction heating coil device of the present invention is formed by joining the side wall joints of the body wall with a polymer adhesive, and the bottom and the lid are wound to the body wall. High-frequency induction heating is used to heat a sealed metal can with relatively high heating efficiency without causing burnout due to abnormal overheating at the T-shaped overlap between the side wall joint and the bottom and lid seam. It has the effect of being able to

Furthermore, the coil device of the present invention has a simple structure,
It is easy to manufacture products with predetermined dimensions to match metal cans, and has advantages such as coil winding in copper tubes and easy passage of water for cooling. Instant heating type heating vending machine. This method has the advantage that it is suitable for rapidly metalizing coffee cans and the like using the above-mentioned metal cans by allowing them to stand still.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a coil device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the distribution of induced current induced in a metal can bonded with a polymer adhesive by the coil device of FIG. 1. , Figure 3 is a front view of a metal can induction heating coil device consisting of a conventional solenoid coil.
Figure 4 is a cross-sectional view of the body wall of an example of a metal can bonded with polymer adhesive, and Figure 5 is the distribution of induced current induced in the metal can bonded with polymer adhesive by the coil device of Figure 3. FIG. 200...metal can, 201...polymer adhesive,
204... Trunk wall part, 205... Side wall joint part, 21
1...Coil, 211a, 211b, 211c,
211d, 211e, 211f, 211g, 21
1h... Annular coil element, 215, 216... Winding portion.

Claims (1)

[Claims] 1 A metal can filled with contents and sealed, which is formed by joining the side wall joints of the body wall with a polymer adhesive, and the bottom and the lid are seamed to the body wall. A high-frequency induction heating coil device for heating the metal can, which is formed so as to approach the outer surface of the body wall and surround the body wall, and to compare the coils with each other in the height direction of the metal can. A metal can comprising a plurality of annular coil elements disposed in close proximity to each other, the annular coil elements being connected such that currents flowing through adjacent coil elements have opposite phases. High frequency induction heating coil device for heating.