JPH0282390A - Automatic vending machine - Google Patents

Abstract

PURPOSE:To maintain the temperature of a canned drink at a fixed level by detecting the variation of the input voltage of a voltage detection circuit when the input voltage varies and changing the heating time in accordance with the input voltage. CONSTITUTION:A heating coil 1 heats canned drink of different quantities by induction and a voltage resonance type inverter circuit 4 is constituted of the heating coil 1, a capacitor for resonance 10, and power switching semiconductor 6 and converts lore-frequency electric power into high-frequency electric power. A siezo-resonance type inverter voltage detection circuit 14 detects the input voltage of the circuit 4 and a heating time decision circuit 13 inputs the output voltage of the circuit 14 and decides the heating time in accordance with the output voltage. A control circuit 12 controls the switching time of the inverter circuit 4 by means of a heating command from the circuit 13 so as to control the figh-frequency electric power. Therefore, the temperature of the canned drink can be maintained at a fixed level after the drink is heated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a vending machine that heats canned beverages such as coffee by induction and sells them hot (hereinafter referred to as hot sales).

BACKGROUND OF THE INVENTION In recent years, vending machines have been proposed that apply induction heating technology to instantaneously heat canned beverages and sell them hot. This type of vending machine, as disclosed in Japanese Utility Model Application Publication No. 54/23696, distinguishes the content of canned drinks, which are heated products, and controls the energization time to the heating coil to keep canned drinks of different content at a constant temperature. Some are equipped with a control device that increases the Such a vending machine will be described below.

Figure 3 shows the size (content capacity) of canned drinks in conventional vending machines.
Indicates a control device that determines the A heating coil 1 inductively heats canned beverages 2a and 2b having different contents. This heated coil/l/1 has an internal capacity. 3 is a sorting lever for sorting these two types of canned drinks 2a and 2b, and 3'
is a sorting switch which is activated by the operation of this sorting lever 3.

This means that when 250!9 canned beverages 20 are introduced into the heating coil/I/1, the selection lever 3 is pushed against the can wall and the sorting switch 3' is turned off. On the other hand, when a short canned beverage 2b of 3/\- of 190 g is introduced, the sorting lever 3 does not come into contact with the can wall, so it springs upward, and this action turns on the sorting switch 3'. That is, the 250g canned beverage 2a generates an off signal for the sorting switch 3', and the 190g canned beverage 2b generates an on signal.

FIG. 4 shows a heating device for heating canned beverages. 4 is a voltage resonance type inverter circuit with a heating coil/l/1° resonance capacitor 5. It is composed of a power switching semiconductor 6 and a reverse conduction diode 7 connected in parallel with the power switching semiconductor 6. 8 is a rectifier circuit that performs full-wave rectification of the commercial power supply, and rectifier 9. The capacitor 10 has a multi-layer structure.

11 is a current detection circuit that detects an input current, converts it into a voltage, and changes the output voltage (1) according to the input current. 12 is a control circuit which outputs the output v of the current detection circuit 11;
1 is connected, the conduction and non-conduction of the power switching semiconductor 6 are controlled so that the output v1 is constant, that is, the input current of the inverter circuit 4 is constant. 13
is a heating time determining circuit which sends a heating command to the control circuit 12 for 20 seconds when the sorting switch 3' is turned off and detects that the beverage is a 250 g can, and for 15 seconds when the sorting switch 3' is turned on and the beverage is detected as a 190 g can. Send. At this time, the control circuit 12 heats the canned beverage while the heating command is being sent.

Note that this heating time is determined by high frequency power, heating efficiency, capacity of the canned beverage, and desired temperature rise value.

The operation of the vending machine configured as above will be explained. First, 3rd. In FIG. 4, when 250 g of canned beverage 2a is introduced into heating coil/I/1, the selection switch 3' is turned off. At this time, the heating time determining circuit 13
determines the heating time and sends a heating command to the control circuit 12 for 20 seconds. Then, the control circuit 12 detects the output v1 of the current detection circuit 11, switches the power switching semiconductor 6 of the inverter circuit 4 so that the output v1 becomes constant, and switches the heating coil /I/1 from the can High frequency power is supplied to the beverage 2a.

In the case of the 190g canned beverage 2b, the heating time determining circuit 13 sends out a heating command for 15 seconds, and other operations remain the same except for the heating time.

Problems to be Solved by the Invention However, in the above configuration, the control circuit 12 controls the high frequency power supplied to the canned beverage by the voltage resonant inverter circuit so that the output (1) of the current detection circuit remains constant. Therefore, even when the input voltage changes, the control circuit controls the high frequency power so that the output v1 of the current detection circuit remains constant, and the current value remains constant even when the input voltage changes. After all, when the input voltage decreases, the high frequency power decreases, and when the input voltage increases, the high frequency power increases. As a result, if the heating time is constant for canned beverages of the same volume, the high frequency power will change, so the temperature at the end of heating the canned beverage will change, and the temperature of the canned beverage may not rise to the selling temperature. However, there were problems such as the temperature exceeding the sales temperature and causing burns to the purchaser.

To 6. In view of the above-mentioned problems, the present invention aims to provide a vending machine that maintains a constant temperature of canned beverages at the end of heating by changing heating time according to changes in input voltage. It is.

Means for Solving the Problems In order to solve the above problems, the vending machine of the present invention includes a heating coil for inductively heating canned beverages of different contents, the heating coil, a resonance capacitor, and a power switching semiconductor. A voltage resonance inverter circuit that converts low frequency power into high frequency power, a voltage detection circuit that detects the input voltage of the inverter circuit, and an output voltage of the voltage detection circuit are input, and the heating time is determined according to the output voltage. The heating time determining circuit includes a heating time determining circuit that determines the heating time, and a control circuit that controls the switching time of the inverter circuit based on the heating command from the heating time determining circuit and controls the high frequency power.

Effect: With the above-described configuration, the present invention detects a change in input voltage with a voltage detection circuit when the input voltage changes, and changes the heating time according to the input voltage, so that even if the high frequency power changes. This makes it possible to maintain a constant temperature at the end of heating the canned beverage.

Example FIG. 1 is a block diagram showing an embodiment of the present invention.

Heated carp/I/1. Inverter circuit 4. Resonance capacitor 5. Power switching semiconductor e+y ion7.
Rectifier circuit 8. Rectifier9. Capacitor 10° Current detection circuit 11. The selection switch in the control circuit 129 is the same as that in the conventional example, so a description thereof will be omitted.

In FIG. 1, 14 is a voltage detection circuit that detects an input voltage and outputs it. The voltage detection circuit 14 includes a resistor R
1, R2, and a peak hold circuit 15. One end of the resistor R1 is connected to the capacitor 1Q, and the other end is connected to the resistor R2. Further, one end of the resistor R2 is connected to the resistor R1, and the other end is connected to GND. Next, the peak halt circuit 15 outputs only the peak value of the output resulting from the voltage division of the resistors R1 and R2. Therefore, if the output voltage of the voltage detection circuit 14 is 2oo when the AC input voltage is 20oV as shown in FIG. 2 (-),
If the AC input voltage is 220V, 1.1v2o0, AC
If the input voltage reaches 18o■, it will be 0.9v2°. So, A
If the C input voltage changes, it will change in proportion to it. 13 is a heating time determining circuit which selects a predetermined time according to the can capacity (according to the signal from the sorting Nuinoch 3'), and also corrects the heating time according to the output voltage of the voltage detection circuit 14, and calculates the corrected time. A heating command is sent to the control circuit 12. The relationship between the AC input voltage and the heating time of the heating time determining circuit 13 is as shown in Fig. 2(b).If the heating time is t2o0 when the AC input voltage is 200V, then if the AC input voltage is 220V, then o, 9t2oIf the OAC input voltage is 180V, set it to 1-1t200. Therefore, the heating time determined by the heating time determining circuit 13 has a slope such that it decreases by 10% if the AC input voltage increases by 10%.

Next, the operation will be explained.

When the canned beverage 2a of V250I is introduced, the sorting switch 3' is turned off and the heating time determining circuit 14 determines the heating time t when the AC input voltage is 20oV.
2°. A heating command is sent to the control circuit 12 for -2o seconds, and the control circuit 12 controls the switching time of the inverter circuit 4. Heating is then terminated after 20 seconds. Next, when the AC input voltage becomes 180 cm, the heating time t is 1-1 t2°. Therefore, the heating command time to the control circuit 12 increases by 10% compared to when the AC input voltage is 2ooV.

As a result, since the input current is controlled to be constant, the high frequency power also decreases by 10% as the input voltage decreases by 10%, but since the heating time increases by 10%, the total power remains constant. When the AC input voltage is 180 V, the heating time determining circuit 13 sends a heating command to the control circuit for 22 seconds, and if heating is performed for 22 seconds, the temperature will rise as when the AC input voltage is 200 V. is obtained, and the heating end temperature of the canned beverage becomes constant. Similarly, the AC input voltage is 220V
Then, the heating time is t2□. is 0.9+2°. Tonashi, A
Compared to when the C input voltage is 200cm, the control circuit 121
The heating command time for Qbe/ is reduced by 10%. As a result, contrary to the above, the high frequency power increases by 10%, but the heating time increases by 10%.
Since the amount of power decreases, the total electric power remains constant, and the temperature at which the canned beverage is heated remains constant. Incidentally, this also applies to the canned beverage 2b of 1909.

According to the configuration of the above embodiment, when the AC input voltage increases, the heating time is decreased by the rate of increase, and when the AC input voltage decreases, the heating time is increased by the rate of decrease, and the control is controlled according to the AC input voltage. By changing the heating instruction time to the circuit 12, the heating end temperature of the canned beverage can be kept constant regardless of changes in the AC input voltage.

Effects of the Invention As is clear from this embodiment, the present invention includes a voltage detection circuit that detects the input voltage of an inverter circuit, a voltage conversion circuit that converts the output voltage of the voltage detection circuit, and an output voltage of the voltage detection circuit. A heating time determining circuit that inputs a voltage and determines a heating time according to the output voltage, and a heating command 11 from the heating time determining circuit. Controls the switching time of the inverter circuit by \-no to control high frequency power. Since it is equipped with a control circuit, even if the AC input voltage changes, the high-frequency power supplied to the canned beverage changes by changing the heating time of the heating time determination circuit. It is possible to keep the heating end temperature of the beverage constant, and prevents the heating end temperature of canned beverages from being too low and unsuitable for sale, or the heating end temperature of canned beverages being too high and causing burns to the purchaser. .

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of an induction heating device for a vending machine showing an embodiment of the present invention, and Figure 2 (a) is a characteristic diagram showing the relationship between AC input voltage and voltage detection circuit output (in Figure 2). is a characteristic diagram showing the relationship between the AC input voltage and the heating time determined by the heating time determining circuit, Figure 3 is a configuration diagram of a conventional vending machine canned beverage content determination device, and Figure 4 is a conventional It is a block diagram of the induction heating device of a vending machine. 4... Inverter circuit, 12... Control circuit, 13... Heating time determining circuit, 14...
...Voltage detection circuit.

Claims (1)

[Claims] A heating coil that inductively heats canned beverages of different contents, a voltage resonance inverter circuit that converts low frequency power to high frequency power and is made up of a resonance capacitor and a power switching semiconductor, and a voltage resonance inverter circuit that detects the input voltage of the inverter circuit. a voltage detection circuit; a heating time determination circuit that inputs the output voltage of the voltage detection circuit and determines the heating time according to the output voltage; and a heating command from the heating time determination circuit to control the switching time of the inverter circuit. A vending machine characterized by being equipped with a control circuit.