JP3190397B2 - Vending machine cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vending machine cooling system provided with a vending machine cooling and heating system.

[0002]

2. Description of the Related Art In recent years, with the diversification of vending machines sold, multi-room hot and cold type vending machines have increased, and a system for cooling multiple rooms with one condensing unit has been proposed. (For example, Japanese Patent Publication No. 60-30
996).

[0003] An outline of a conventional vending machine is shown in FIG.
This will be described with reference to FIG. In the figure, 1 is a main body cabinet of a vending machine, 2A is a cold exclusive product storage room, 2
B is a hot or cold product storage room. An in-compartment fan 3A and an evaporator 4A are installed in the cold product storage room 2A, and an in-compartment fan 3B, an evaporator 4B, and a heater 5 are installed in the hot or cold product storage room 2B. In the lower machine room of the main body cabinet 1, a condensing unit 9 of a refrigerator, which is a combination of a compressor 6, an external fan 7, and a condenser 8, is provided. A refrigerant circuit is formed by the evaporators 4A and 4B. Make up.

The evaporators 4A and 4B are connected to a condensing unit 9 via a capillary tube 10 in parallel with each other. 11A is a branch refrigerant circuit of the evaporator 4A, and 11B is a branch refrigerant circuit of the evaporator 4B.

[0005] Reference numeral 12 denotes a second solenoid valve, which is a branch refrigerant circuit 11B.
Is inserted and connected to the entrance side. A first thermostat 13A is arranged on the evaporator 4A and controls the cold temperature of the cold dedicated product storage room 2A. 13
B is a second thermostat disposed on the evaporator 4B and controls the cold temperature of the hot or cold product storage room 2. A thermostat 14 is disposed on the heater 5 and controls the hot temperature of the hot or cold product storage room 2.

Reference numeral 15 denotes a cold / hot changeover switch for switching between hot control and cold control of the hot or cold product storage room 2. Reference numeral 16 denotes a first solenoid valve, which is a refrigerant distribution circuit 1
It is inserted and connected to the inlet side of 1A. A first relay 17 is connected in series with the first thermostat 13A in parallel with the first solenoid valve 16 in an electric circuit. 17 'is a contact of the first relay 17. Reference numeral 18 denotes a second relay, which is connected in series with the second thermostat 13B in parallel with the second solenoid valve 12 in an electric circuit manner.

Reference numeral 18 'denotes a contact point of the second relay 18, one of which is connected in parallel with the first relay 17 in terms of an electric circuit, and the other is connected in series with the second relay 18. 19 is the third
Are connected in series with the contact 17 'of the first relay and the contact 18 of the second relay, which are electrically connected in parallel. Reference numeral 19 'denotes a third relay contact, one of which is connected in parallel with the second relay contact 18 and in series with the second relay 18. The other is electrically connected in series with the condensing unit 9 and controls the condensing unit 9.

The operation of the cooling device for a vending machine configured as described above will be described below. When both the cold dedicated product storage room 2A and the hot or cold product storage room 2B are set to be cold, the first thermostat 13A
Is turned off, the first solenoid valve 16 and the contact 17 'of the first relay are turned off. And the second thermostat 1
When 3B is turned off, the second solenoid valve 12 and the contact 18 'of the second relay are turned off.
Is turned off, the condensing unit 9 is turned off.

The same applies when the second thermostat 13B is turned off before the first thermostat 13A. The condensing unit 9 does not turn off unless both the first thermostat 13A and the second thermostat 13B are turned off. When the second thermostat 13B is turned on, the second solenoid valve 12 is turned on but the contact of the second relay 18 is not turned on.

When the first thermostat 13A is turned on, the first solenoid valve 16 and the contact 17 'of the first relay are turned off.
Then, the condensing unit 9 is turned on because the contact 19 'of the third relay is turned on. Therefore, the condensing unit 9 is turned on by turning on the first thermostat 13A.
Is turned on, a predetermined cooling performance can be obtained in both the cold dedicated product storage room 2A and the hot or cold product storage room 2B.

[0011]

However, in the above-mentioned conventional configuration, when the refrigerant flows through both the evaporators 4A and 4B, the pressure is reduced in the two capillary tubes 10, but only one of the evaporators 4A and 4B. When the refrigerant is flowing through the capillary tube 10, the amount of pressure reduction becomes one capillary tube 10. Therefore, when the change in the flow rate is large and the refrigerant flows only through one capillary tube 10, the condensation capacity of the condenser 8 is too large. Therefore, the high-pressure pressure of the condensing unit 9 is reduced, so that the amount of circulating refrigerant is reduced, the amount of refrigerant flowing to the evaporator is reduced, and a predetermined cooling performance cannot be accurately obtained.

The present invention has been made in view of the above problems, and has been made in consideration of high pressure and low pressure.
The condensing capacity is changed according to the pressure change to reduce the amount of circulating refrigerant.
The purpose of the present invention is to provide a cooling device for a vending machine which is kept constant .

[0013]

[0014]

According to the present invention, there is provided a vending machine cooling apparatus comprising a compressor, a first condenser and a second condenser .
A condenser and a capillary tube and an evaporator provided in each of the plurality of product storage chambers are sequentially connected in a ring shape; a high-pressure side pressure sensor provided on the second condenser outlet side; and an outlet of the plurality of evaporators. a low side pressure sensor provided on the side is merged junction, a condenser fan motor, a frequency converter for changing the rotational speed of the condenser fan motor by changing the frequency to be output to the condenser fan motor, the high pressure Pressure detected by the side pressure sensor and before
The pressure detected by the low pressure side pressure sensor is higher than the reference value.
If so, increase the rotation speed of the condenser fan motor,
If it is lower than the reference value, the condenser fan motor
A control device for controlling the output frequency of the frequency conversion device for reducing the rotation .

[0015]

[0016]

According to the cooling device of the vending machine of the present invention, the control device
The pressure detected by the high pressure side pressure sensor and the low pressure side pressure
If the pressure detected by the force sensor is higher than the reference value,
Increase the rotation speed of the condenser fan motor and
If it is too low, reduce the rotation of the condenser fan motor.
That controls the output frequency of the frequency converter, changes the rotational speed of the condenser fan motor by the output frequency of the frequency converter, the amount of circulating refrigerant is kept constant because condensation capacity is changed.

[0017]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. The same components as those of the prior art will be denoted by the same reference numerals and detailed description thereof will be omitted. 1 to 3
1 shows a cooling device for a vending machine according to a first embodiment of the present invention.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

In FIG. 1, a first condenser 8A on the compressor 6 side, a second condenser 8B on its outlet side, and a pressure sensor 22 on its outlet side are connected in series in that order. The pressure sensor 23 is an evaporator 4A, 4
It is installed on the exit side after the merging of B. In FIG.
The frequency converter 24 is connected in series with the condenser fan motor 7.

FIG . 3 is a block diagram, wherein 25 is a power supply, 26 is a rectifier circuit, 27 is a control device constituted by a microcomputer, 28
Denotes an operation unit, and 29 denotes a display unit.

The operation of the first embodiment configured as described above will be described. The AC voltage of the power supply 25 is applied to the frequency exchange device 24 converted to DC by the rectifier circuit 26. The frequency converter 24 continuously varies the output frequency according to the digital signal of the controller 27 to change the rotation speed of the condenser fan motor 7.

On the other hand, the controller 27 controls the pressure condenser 2
2. Deriving pressure data of the pressure sensor 23 as an input of the microcomputer, performing logical operation processing based on a pressure setting condition from the operation unit 28 or a preset program, and giving a frequency setting signal to the frequency conversion device 24, and displaying the signal. The unit 17 displays the status of each unit as necessary. Next, an example of the relationship between the pressure sensor 22, the pressure sensor 23, and the frequency given to the condenser fan motor 7 is shown in (Table 1).

[0029]

[Table 1]

In this embodiment, since the capacity of the condenser fan motor 7 is determined corresponding to the pressure sensor 22 and the pressure sensor 23, the shortage of refrigerant in the evaporators 4A and 4B is eliminated, the cooling system is operated efficiently, and the inside of the refrigerator is quickly operated. It can be cooled efficiently.

[0031]

As described above, the cooling device for a vending machine according to the present invention comprises a compressor, a first condenser and a second condenser .
Sensor, a capillary tube and an evaporator provided in each of the plurality of product storage chambers are sequentially connected in a ring shape, and a high-pressure side pressure sensor provided on the second condenser outlet side and an outlet of the plurality of evaporators are provided. <br/> A low-pressure side pressure sensor provided in a portion where the sides are joined and joined , a condenser fan motor, and a frequency converter that changes the frequency of the condenser fan motor by changing the frequency output to the condenser fan motor. And the pressure detected by the high pressure side pressure sensor and the pressure
The pressure detected by the low pressure side pressure sensor is higher than the reference value.
Increase the number of rotations of the condenser fan motor,
If it is lower than the reference value, the rotation of the condenser fan motor
A control device for controlling the output frequency of the frequency conversion device for reducing the rotation .

[0032]

[0033]

Accordingly, the control device controls the output frequency of the frequency conversion device based on the pressure data detected by the high pressure side pressure sensor and the low pressure side pressure sensor, and the rotation frequency of the condenser fan motor is controlled by the output frequency of the frequency conversion device. In other words, the condensing capacity changes, so that the refrigerant circulation amount is kept constant, and a stable cooling operation can be performed.

Further, since the number of revolutions of the condenser fan motor changes depending on the output frequency of the frequency converter, the operation of the condenser fan motor is smooth and efficient.

Further, the efficiency of the cooling system is high, so that energy can be saved, and even if there is a change in the load in the product storage room, a predetermined cooling performance can be obtained immediately, thereby increasing the ability to attract customers.

[Brief description of the drawings]

FIG. 1 is a refrigerant piping diagram of a cooling device of a vending machine according to a first embodiment of the present invention.

FIG. 2 is a control circuit diagram of a cooling device of the vending machine of the embodiment.

FIG. 3 is a block diagram of a cooling device of the vending machine of the embodiment.

FIG. 4 is a front view of a cooling device of a conventional vending machine.

FIG. 5 is a side view of a conventional vending machine cooling device.

FIG. 6 is a refrigerant piping diagram of a cooling device of a conventional vending machine.

FIG. 7 is a control circuit diagram of a conventional vending machine cooling device.

[Explanation of symbols]

 2A, 2B Commodity storage room 4A, 4B Evaporator 6 Compressor 7 Condenser fan motor 8A First condenser 8B Second condenser 10 Capillary tube 22 Pressure sensor 23 Pressure sensor 24 Frequency conversion device 27 Controller

Continuation of the front page (56) References JP-A-58-10074 (JP, A) JP-A-59-133965 (JP, U) JP-B-60-30996 (JP, B2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) F25D 11/00 101 F25B 6/04 G07F 9/10

Claims (1)

(57) [Claims] 1. A compressor, a first condenser and a second condenser .
A condenser, a capillary tube and an evaporator provided in each of the plurality of product storage chambers are sequentially connected in a ring shape, and a high-pressure side pressure sensor provided on the second condenser outlet side and an outlet of the plurality of evaporators are provided. a low side pressure sensor provided on the side is merged junction, a condenser fan motor, a frequency converter for changing the rotational speed of the condenser fan motor by changing the frequency to be output to the condenser fan motor, the high pressure Pressure detected by the side pressure sensor
And the pressure detected by the low pressure side pressure sensor is higher than a reference value.
Higher, increase the rotation speed of the condenser fan motor.
If it is lower than the reference value, the condenser fan
A control device for controlling the output frequency of the frequency conversion device for lowering the rotation of the vending machine.