KR19990015382A - Boiling water prevention device of vending machine - Google Patents

Abstract

The present invention relates to an apparatus for preventing boiling of water in a vending machine, the automatic vending machine having a hot water tank in which a heater is turned on and off through a temperature control thermostat and an overheat prevention thermostat: a pressure rises by boiling water inside the hot tub. And a pressure switch for turning on the contact point on the upper end of the hot water tank, and operating a cutoff relay for turning off the power applied to the heater when the contact point of the pressure switch is turned on.

Accordingly, in the vending machine that sells hot drinks such as coffee, the water in the hot water tank boils over the controller and does not lead to another accident.

Description

Boiling water prevention device of vending machine

The present invention relates to an apparatus for preventing boiling of water in a vending machine, and more particularly, in a vending machine that sells hot drinks such as coffee, the water of a vending machine that does not boil over the water in the hot water tank and leads to another accident. It relates to a boiling prevention device.

Referring to FIG. 1, generally, a vending machine that sells hot beverages includes a raw material container 11 that separates and stores coffee and domestic tea, and a water container 12 that stores water for liquefying raw materials in powder form. And a hot water tank 13 for maintaining the water flowing from the bucket 12 at a constant temperature, and a controller 20 for displaying the charged amount and supporting the beverage selection. The beverage selected from the operation panel (not shown) is mixed in the proper mixture from the raw material container 11 according to the instruction of the controller 20, and is added to the discharge port after the water is added from the hot water container 13.

In the vending machine of such a configuration, a heater 14 for heating is installed at the lower part of the hot water tank 13, a temperature control thermo 15 is installed at the top to maintain a constant temperature, and a heater when the water temperature exceeds the side ( 14 is installed overheat protection thermo 16 to block. The overheat protection thermo 16 usually uses a bimetal type, but the frequency of operation is not so high, but it serves as a safety device.

However, if the heater 14 of the hot water tank 13 continues to be energized due to a poor temperature control thermo 15, the water is boiled. At this time, if the overheat prevention thermo 16 is not operated, the inside of the vending machine is filled with water vapor and the controller ( 20) The internal microcomputer and the like not only cause an error, but also the raw material of the raw material container 11 is deformed.

Therefore, an object of the present invention is to provide an apparatus for preventing boiling of water in a vending machine, which prevents water from boiling in the hot water tank over the controller in a vending machine for selling hot drinks such as coffee and so on, which does not lead to another accident.

1 is a perspective view showing a main part of a vending machine to which the present invention is applied;

2 is a circuit diagram of an essential part for performing control according to the present invention.

Explanation of symbols on the main parts of the drawings

11: raw material container 12: bucket

13: hot water bottle 14: heater

15: Thermostatic Thermo 16: Overheating Thermo

20: controller 21: pressure switch

22: disconnect relay 23: pushbutton

In order to achieve the above object, the present invention provides a vending machine having a hot water tank in which a heater is built-in through a thermostat and an overheat prevention thermostat: to turn on a contact when the pressure is increased by boiling water inside the hot water tank. The pressure switch is mounted on the upper end of the hot water tank, and when the contact point of the pressure switch provides a water boiling prevention device for a vending machine, characterized in that to operate a shut-off relay for turning off the power applied to the heater.

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

Referring to FIG. 1, the present invention provides a pressure switch 21 in a vending machine having a hot water tank 13 in which a heater 14 that is turned on and off through a temperature control thermo 15 and an overheat prevention thermo 16 is installed. Add and modify the circuit of controller 20.

The pressure switch 21 according to the present invention is mounted on the upper end of the hot water tank 13 and to turn on the contact when the pressure rises by boiling water inside the hot water tank 13. The pressure switch 21 is installed in the upper position so as not to directly contact the water of the hot water tank 13. The hot water tank 13 generally has a cover which opens the upper part, and when the pressure switch 21 is mounted on the cover, the inspection and maintenance are also easy. It is preferable that the pressure switch 21 use a mechanical type such as a Bourdon tube rather than an electronic type such as a piezoelectric element.

At this time, the pressure switch 21 has a set pressure exceeding 1 atm, but close to the maximum, and an operating temperature of at least 120 ℃. When the heater 14 continues to operate and the water in the hot water tank 13 starts to boil, the steam pressure of the hot water tank 13 exceeds 1 atmosphere, but the pressure switch 21 responds to this condition. In this state, since the steam temperature also exceeds 100 ° C., heat resistance and operational reliability of the pressure switch 21 are also required.

2 is a circuit diagram of an essential part for performing control according to the present invention.

According to the present invention, when the contact point of the pressure switch 21 is turned on, a shutoff relay 22 for turning off the power applied to the heater 14 is used. The heater 14 is connected to the power supply via the temperature control thermo 15 and the overheat prevention thermo 16 may receive another control signal from the microcomputer. The normally closed b contact 22b of the shutoff relay 22 operated by the pressure switch 21 is connected to the AND circuit together with the thermostat thermostat 15 and the overheat prevention thermostat 16. As such, it is preferable in view of durability and operational reliability of the pressure switch 21 to intervene the shutoff relay 22 without directly connecting the pressure switch 21 on the heater 14 circuit.

At this time, the pressure switch 21 is connected in parallel with a contact point 22a of the cutoff relay for maintaining the ON state of the cutoff relay 22 and in series circuit with the pushbutton 23 for releasing the self holding. It is also possible to make the connection. When the self-holding circuit is configured in the pressure switch 21 and the shutoff relay 22, the water temperature of the hot water tank 13 is slightly lowered, thereby preventing the error of repeated progress of the heater being operated again.

The vending machine of the present invention to which such a configuration is applied turns off the heater 14 when the steam pressure in the hot water tank 13 becomes high when the temperature control thermo 15 and the overheat prevention thermo 16 are defective or malfunction. Be sure to This state remains until the administrator presses pushbutton 23 after taking the appropriate action.

Meanwhile, the alarm buzzer BZ and the lamp LP may be energized when the pressure switch 21 is operated. In this case, the alarm buzzer BZ and the lamp LP of the cutoff relay 22 are connected to branch from the cutoff relay 22.

Water boiling prevention device of the vending machine according to the present invention having the above configuration and action has the effect that the water in the hot water tank boils over the controller in the vending machine that sells hot beverages such as coffee does not lead to another accident. .

Claims (3)

For vending machines with hot water baths with built-in heaters switched on and off by means of thermostatic and overheat protection thermostats: Mounting a pressure switch on the top of the hot water tank to turn on the contact when the pressure is increased by boiling water in the hot water tank, When the contact point of the pressure switch is on, the boiling water preventing device of the vending machine, characterized in that for operating the shut-off relay to turn off the power applied to the heater. The method of claim 1, wherein the pressure switch A water boiling prevention device of a vending machine, characterized by having a set pressure exceeding 1 atm but having a maximum proximity and an operating temperature of at least 120 ° C. The pressure switch of claim 1 or 2, wherein the pressure switch The boiling point preventing device of the vending machine, characterized in that connected to the parallel circuit and the contact a of the blocking relay for self-maintaining the on-state of the cut-off relay, and connected to the push button and the series circuit for releasing the self-holding.