JPH08189740A - Refrigerating device for automatic vending machine - Google Patents

Abstract

PURPOSE: To perform a quick cooling by a method wherein a temperature difference between respective evaporators, which is detected by a temperature sensor is judged, and when the temperature difference between the evaporators becomes larger than a specified value, a a valve for evaporator which communicates with the evaporator of which the temperature is lower is closed for a specified period of time. CONSTITUTION: Temperature sensors 5a-5c detect temperatures in evaporators 4a-4c, and convert the temperatures into electric signals, and output to a controller 3. The controller 3 controls ON/OFF of electromagnetic valves 7a-7c conforming to a control program, and controls the opening degree of an electronic expansion valve 12, and also controls other respective parts of a cooling device. The controller 3 judges a temperature difference between the evaporators 4a-4c detected by the temperature sensors 5a-5c in the evaporators, and when the temperature difference becomes larger than a previously determined value, the controllers 3 controls the electromagnetic values 7a-7c which communicate with the evaporators 4a-4c in such a manner that the electromagnetic valve communicating with the evaporator of which the temperature is lower may be closed for a first specified period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device mounted in an automatic vending machine for selling products such as canned beverages to cool the products.

[0002]

2. Description of the Related Art Conventionally, a cooling device shown in FIG. 4 has been known as a cooling device mounted on an automatic vending machine for selling products such as canned beverages. This cooling device 51 includes a compressor (compressor) 60, a condenser (condenser) 61, a distributor 58, electromagnetic valves 57a and 57b, capillaries (capillary tubes) 53a and 53b, and evaporators (evaporators) 54a and 54b. And the accumulator 59
And a refrigerant pipe 56 that connects them in series and constitutes a closed circuit refrigeration circuit.
A refrigerant such as Freon is enclosed in the refrigerant pipe 56,
It circulates in this refrigeration circuit.

With the above configuration, the capacitor 61
The refrigerant that has been condensed and liquefied in (1) is sent to the distributor 58 through the refrigerant pipe 56 and is branched into two. The electromagnetic valves 57a and 57b are ON (open) / OFF (closed) type valves and are controlled to be opened and closed by a controller (not shown) or the like. The capillaries 53a and 53b are a kind of capillaries and are adjusted so that even if the amount of the refrigerant flowing through either of the two branched refrigerant pipes 56a or 56b fluctuates, the refrigerant flows evenly through the respective evaporators 54a and 54b on the downstream side. . The liquid refrigerant that has flowed into the evaporators 54a and 54b is depressurized and vaporized in the evaporators 54a and 54b, and at this time, the latent heat of the refrigerant is removed from the evaporator and its surroundings to perform cooling. Each evaporator 54a
And the refrigerant discharged from 54b is stored in the accumulator 59 by 1
It joins two tubes and is sent to the compressor 60. The refrigerant is compressed by the compressor 60 and becomes a high temperature and high pressure gas.
This high-temperature, high-pressure gaseous refrigerant is sent to the condenser 61, cooled by a heat radiation fan or the like, and liquefied. The liquefied refrigerant is sent again to the evaporators 54a and 54b by the refrigerant pipe 56 and used again for cooling.

Inside the vending machine in which the cooling device 51 is mounted, there are provided three product storage compartments (not shown) partitioned by heat insulating partition walls. One is a product storage dedicated to cooling, and two product storages have a structure capable of both cooling and heating. Therefore, the single product storage dedicated to cooling has no evaporator and has a structure in which cold air or hot air can circulate, and the evaporator 54a is one of the single product storage dedicated to cooling. It is installed inside and cools the products in both of these product storages. Further, the evaporator 54b is installed inside the above-mentioned cooling / heating dual-purpose product storage,
The products in the dual-purpose cooling / heating product storage are cooled.

With this configuration, for example,
In winter, the solenoid valve 57b is closed to stop the supply of the refrigerant to the evaporator 54b in the above-mentioned cooling / heating commodity storage box, and instead operate a heater (not shown) to heat one commodity storage box. In this way, the circulation with the inside of the exclusive cooling room is cut off, and heating is performed by the heater of the storage room without the evaporator. On the other hand, in the summer, both solenoid valves 57a, 5a
7b can be opened, a refrigerant can be supplied to both evaporators 54a and 54b, and the inside of three goods storage can be cooled.

[0006]

However, in the above-described conventional cooling device for a vending machine, the cooling medium is cooled by flowing the refrigerant into the evaporator 54b in the storage compartment for heating / cooling / both heating which is not used in winter. When the operation is restarted, there is a drawback that the refrigerant tends to flow toward the evaporator 54a that is already operating, and the cooling of the evaporator 54b does not proceed easily.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a cooling device for a vending machine capable of rapid cooling.

[0008]

In order to solve the above-mentioned problems, a cooling device for a vending machine according to the invention described in claim 1 has a part of a refrigeration circuit in each of a plurality of product storages. Cooling of a vending machine configured to install the constituent evaporators, and to send the refrigerant to each of the evaporators to evaporate the refrigerant in each of the evaporators to cool the plurality of commodity storage boxes independently of each other. In the device, an evaporator valve which is provided in the inlet side refrigerant pipe of each evaporator and which can be opened or closed,
A temperature sensor for detecting the temperature in each of the evaporators and a temperature difference between the evaporators detected by the temperature sensors are determined, and when the inter-evaporator temperature difference becomes larger than a predetermined value. Control means for controlling the evaporator valve communicating with the evaporator having the lower temperature to be closed for a first predetermined time.

Further, in the cooling device for a vending machine according to the present invention as defined in claim 2, an evaporator forming a part of a refrigeration circuit is installed in each of the plurality of product storages, and each of the evaporators is provided with the evaporator. In the cooling device of the vending machine configured to cool the plurality of product storage boxes independently of each other by sending the refrigerant to evaporate the refrigerant in each of the evaporators, the inlet side refrigerant pipe of each of the evaporators An evaporator valve that is provided and that can be opened or closed, a temperature sensor that detects the temperature in each evaporator, and a temperature difference between the evaporators that is detected by the temperature sensors are determined, and the temperature between the evaporators is determined. When the temperature difference becomes larger than a predetermined value, the evaporator valve leading to the evaporator having the lower temperature is closed for a first predetermined time, and after the first predetermined time elapses, a second predetermined time. Until the temperature elapses Configured to include a control means for controlling to stop the determination of the difference, the.

[0010]

According to the first aspect of the present invention having the above structure, the temperature sensor detects the temperature in each evaporator. The control means determines an inter-evaporator temperature difference, which is a difference between the temperatures in the respective evaporators detected by the respective temperature sensors, and when the inter-evaporator temperature difference becomes larger than a predetermined value, the temperature is low. A closing control signal is output to the evaporator valve communicating with the other evaporator. The evaporator valve that has output the closing control signal is closed for the first predetermined time. As a result, no refrigerant is supplied to the evaporator communicating with the closed evaporator valve, and cooling is not performed in the evaporator for at least the first predetermined time.

According to the second aspect of the present invention having the above structure, the temperature sensor detects the temperature in each evaporator.
The control means determines an inter-evaporator temperature difference, which is a difference between the temperatures in the respective evaporators detected by the respective temperature sensors, and when the inter-evaporator temperature difference becomes larger than a predetermined value, the temperature is low. A closing control signal is output to the evaporator valve communicating with the other evaporator. The evaporator valve that has output the closing control signal is closed for the first predetermined time. As a result, no refrigerant is supplied to the evaporator communicating with the closed evaporator valve, and cooling is not performed in the evaporator for at least the first predetermined time. After the first predetermined time has elapsed, the control means controls the second
The determination of the inter-evaporator temperature difference is stopped until the predetermined time elapses. During this period, for example, normal cooling control is performed. Then, the control means restarts the determination of the inter-evaporator temperature difference when the second predetermined time has elapsed after the first predetermined time has elapsed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an automatic vending machine 100 equipped with a cooling device 1 according to an embodiment of the present invention has three product storage boxes 20a, 20b, 20c partitioned by heat insulating partition walls.
It has.

The cooling device 1 shown in FIG.
, A refrigerant pipe 6 which is a refrigerant pipe, evaporators 4a, 4b and 4c which are three evaporators, and temperature sensors 5a and 5
b, 5c and a controller 3 as a control means. Each evaporator 4a-4c is arrange | positioned inside each of each goods storage 20a-20c.

The cooling device main body 2 is provided with a compressor, a condenser, an electromagnetic valve, etc., which will be described later, and supplies a liquid refrigerant for cooling. The liquid refrigerant supplied from the cooling device main body 2 is sent to the evaporators 4a to 4c by the refrigerant pipe 6 and evaporated in the evaporators 4a to 4c to remove the latent heat of the refrigerant from the evaporator and its surroundings to store each product. Product G that is stored inside after cooling the inside independently
To cool. The temperature sensors 5a to 5c are provided in the evaporators 4a to 4c, detect the temperature TE in the evaporators 4a to 4c, and output it to the controller 3 as a temperature signal. The controller 3 receives the temperature signals from the temperature sensors 5a to 5c, monitors the temperatures TEa to TEc in the evaporators 4a to 4c, and outputs a control signal to the cooling device body 2 according to each condition.

Two of the three product storage boxes 20a to 20c, for example, the product storage boxes 20a and 20b are assigned to the product storage boxes dedicated to cooling the product G such as a canned beverage, and the other one. One product storage, for example, product storage 20c is assigned to the product storage that performs both cooling and heating. Therefore, for example, a heater (not shown) is provided inside the product storage 20c.

With this configuration, for example,
Evaporator 4 in the above-mentioned product storage 20a and 20b
The refrigerant is constantly supplied from the cooling device main body 2 to a and 4b to cool the product, but in the winter, the controller 3 outputs a control signal to the cooling device main body 2 to cool the product.
A solenoid valve, which will be described later, such as a solenoid valve 7c (see FIG. 2) is closed to stop the refrigerant supply to the evaporator 4c in the commodity storage 20c for both cooling / heating and operate a heater (not shown) instead. To heat the inside of the product storage 20c, and in summer, output a control signal from the controller 3 to the cooling device main body 2 to open a solenoid valve (for example, 7c (see FIG. 2)) to be described later in the cooling device main body 2. However, the refrigerant can be supplied to the evaporator 4c so that the inside of the product storage 20c can also be cooled. This product storage 20c
Switching between the heating mode and the cooling mode is performed by a changeover switch (not shown) for controlling ON / OFF of the solenoid valve 7c.

Next, a more detailed structure of the cooling device 1 will be described with reference to FIG. As shown in the figure,
The cooling device 1 includes a compressor (compressor) 10, a condenser (condenser) 11, an electronic expansion valve 12, a distributor 8, and solenoid valves 7a, 7 which are valves for an evaporator.
b, 7c, evaporators 4a, 4b, 4c, temperature sensors 5a, 5b, 5c, accumulator 9, and refrigerant pipes 6, 6a, 6b that form a closed circuit refrigeration circuit while connecting these in series. 6c and controller 3
It is configured with. A refrigerant such as freon is sealed in the refrigerant pipe 6 and circulates in the refrigeration circuit. Here, the compressor 10, the condenser 11,
Electronic expansion valve 12, distributor 8, solenoid valve 7
The a to 7c, the accumulator 9, and the refrigerant pipes 6 and 6a to 6c connecting these in series constitute the cooling device main body 2.

The solenoid valves 7a to 7c and the electronic expansion valve 1 described above.
A signal line for outputting a control signal from the controller 3 is connected to 2. Further, the refrigerant pipe 6 is branched into three by a distributor 8 downstream of the electronic expansion valve 12,
It becomes the refrigerant pipes 6a, 6b, 6c of the book. Refrigerant pipe 6
The solenoid valve 7a and the evaporator 4a are connected in series to a, and the solenoid valve 7b and the evaporator 4b are connected to the refrigerant pipe 6b.
However, the solenoid valve 7c and the evaporator 4c are connected in series to the refrigerant pipe 6c, respectively. The three refrigerant pipes 6 a, 6 b, 6 c are joined to one refrigerant pipe 6 downstream of the evaporators 4 a to 4 c and connected to the accumulator 9. Also, the compressor 10 and the condenser 1
A refrigerant pipe (not shown) in which a muffler for preventing overheating of the compressor 10 is interposed may be circulated between 1 and 1.

With the above configuration, the capacitor 11
The refrigerant condensed and liquefied in (1) is sent to the electronic expansion valve 12 through the refrigerant pipe 6. The electronic expansion valve 12 is a variable valve opening type expansion valve equipped with, for example, a stepping motor, and the valve opening is digitally controlled by a control signal output from the controller 3. This control signal is composed of, for example, a pulse signal, the valve opening degree is increased or decreased according to the number of pulses, and the supply amount of the refrigerant to each of the evaporators 4a to 4c is adjusted here.

The refrigerant passing through the electronic expansion valve 12 is sent to the distributor 8 and is branched into three. The solenoid valves 7a to 7c on the downstream side are valves that are controlled to be in either an ON (open) or OFF (closed) state, and are opened / closed by a control signal from the controller 3.

The liquid refrigerant flowing into each of the evaporators 4a to 4c is depressurized and vaporized in each of the evaporators 4a to 4c, and at this time, the latent heat of the refrigerant is taken from the evaporator and its surroundings to be cooled. Each evaporator 4a-4c
The refrigerant discharged from the refrigerant merges into one refrigerant pipe 6 by the accumulator 9 and is sent to the compressor 10. The refrigerant is compressed by the compressor 10 and becomes high-temperature and high-pressure gas. The high-temperature and high-pressure gaseous refrigerant is sent to the condenser 11 and cooled by a heat radiation fan or the like to be liquefied. This liquefied refrigerant is again fed through the refrigerant pipe 6 to the evaporator 4
a to 4c and used again for cooling.

The temperature sensors 5a to 5c are sensors such as thermistors, and detect the temperatures TEa to TEc in the evaporators 4a to 4c, convert them into electric signals, and output them to the controller 3. The controller 3 includes a microprocessor (not shown), a ROM and a RAM, and operates according to an external operation or a control program stored in the ROM.
ON / OFF control of the solenoid valves 7a to 7c, valve opening control of the electronic expansion valve 12, and control of other parts of the cooling device are performed.

Next, the control procedure in the controller 3 of the cooling device 1 of this embodiment will be described with reference to the flow chart of FIG.

First, the temperature signals from the temperature sensors of the respective evaporators are compared with each other to obtain the temperature difference between the respective evaporators. That is, based on the temperature TEi in the evaporator i output from each temperature sensor and the temperature TEj in another evaporator j, the controller 3 for each evaporator, the inter-evaporator temperature difference ΔTij (= evaporator-to-evaporator temperature difference). | TEi-TEj |: general formula) is calculated. Here, || indicates an absolute value symbol. In this embodiment, since there are three evaporators 4a, 4b, and 4c, the temperature difference Δ
Tij is ΔTab = | TEa−T for each evaporator.
Eb |, ΔTbc = | TEb−TEc |, ΔTca = | TEc−TEa
| Will be calculated respectively.

Next, it is judged whether or not the inter-evaporator temperature difference ΔTij thus obtained is larger than a predetermined value ΔTo (step S1). as a result,
If “NO”, i or j is changed, and the same determination is repeated for the combination with another evaporator. "YE
If "S", the process proceeds to the next step S2. The result of step S1 being "YES" means that the temperature TEi in a certain evaporator i is larger than the temperature TEj in another evaporator j by a value larger than a predetermined value ΔTo, or the temperature TEi in a certain evaporator i. Is smaller than the temperature TEj in the other evaporator j by a value larger than the predetermined value ΔTo.

Next, in step S2, it is determined whether or not the temperature TEi of a certain evaporator is lower than the temperature TEj of another evaporator. As a result, if "YES", it means that the temperature TEi in one evaporator i is smaller than the temperature TEj in another evaporator j by a value larger than the predetermined value ΔTo. That is, in this case, the temperature TEi in one evaporator i is sufficiently cooled and lower than the temperature TEj in another evaporator j, and the temperature difference is larger than the predetermined value ΔTo. Hereinafter, the evaporator i cooled to the minimum temperature will be referred to as the "minimum cooling evaporator". In this case, the process proceeds to the next step S3.

In step S3, the controller 3 outputs a closing control signal for closing a control valve (for example, a solenoid valve 7a) that controls the amount of refrigerant to the sufficiently cooled minimum cooling evaporator i (for example, the evaporator 4a). . When this closing control signal is output, a control valve (for example, solenoid valve 7
(a) is completely closed, and the supply of the refrigerant to the lowest temperature evaporator among the three evaporators is stopped.

Next, the controller 3 measures the elapsed time after closing the control valve (for example, the solenoid valve 7a) (step S4), and when the first predetermined time of 5 minutes has elapsed, The open control signal is sent to the control valve (for example, the solenoid valve 7).
Output to a). When this opening control signal is output, the control valve (for example, the solenoid valve 7a) is completely opened (step S
5). Therefore, the control valve (for example, the solenoid valve 7a) is completely closed during 5 minutes after the closing control signal is output until the opening control signal is output. As a result, no refrigerant is supplied to the lowest cooling evaporator i (e.g., the evaporator 4a), and the cooling is stopped in the evaporator i for at least 5 minutes.

After the opening control signal is output,
Refrigerant is supplied to the lowest cooling evaporator i (e.g., evaporator 4a), and cooling in this evaporator i (e.g., evaporator 4a) is restarted.

Next, the controller 3 is the second predetermined time 10 after the elapse of the first predetermined time of 5 minutes (that is, after opening the electromagnetic valve (for example, the electromagnetic valve 7a) to the evaporator i). Until the time elapses, the temperature difference between evaporators ΔTij is not determined (see step S1). During this period, for example, when the temperature inside the evaporator controlled by a certain internal temperature rises above a certain temperature (for example, the upper limit temperature TU), the solenoid valve communicating with the evaporator is opened, but the inside of the evaporator is opened. When the temperature of (1) has dropped to another specific temperature (for example, the lower limit temperature TL), the "normal cooling control" such as closing the electromagnetic valve leading to the evaporator is performed (step S6). In this "normal cooling control", the controller 3 may output a control signal to the electronic expansion valve 12 as necessary to control the valve opening degree.

Next, the controller 3 measures the time, and after the first predetermined time of 5 minutes has elapsed and the second predetermined time of 10 minutes has elapsed (step S7), the temperature inside the evaporator is decreased. Monitoring and temperature difference between evaporators ΔTij
Restart the judgment of. That is, the second predetermined time period corresponds to a grace period until re-determination of the inter-evaporator temperature difference ΔTij.

If the determination result is "NO" in step S2, the temperature TEj in the evaporator j is increased.
Is sufficiently cooled and lower than the temperature TEi in the other evaporator i, and the temperature difference is larger than the predetermined value ΔTo, so that the solenoid valve (for example, the solenoid valve 7c) communicating with the evaporator j (for example, the evaporator 4c) is connected. about,
The procedure similar to the procedure after step S3 is executed.

By performing the above-mentioned control, a cooled evaporator that is sufficiently cooled as compared with other evaporators and does not require further cooling is found, and the first supply of the refrigerant to this cooled evaporator is performed. Since the uncooled evaporator (for example, the evaporator 4c) that has not been cooled sufficiently is supplied with sufficient refrigerant, the uncooled evaporator can be rapidly cooled because it is stopped for a predetermined time of 5 minutes. That is, effective and rapid cooling is performed in an evaporator immediately after switching from the heating mode to the cooling mode, which is installed in the product storage for both cooling and heating, and an evaporator in which cooling load suddenly increases and cooling becomes difficult. It becomes possible.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the claims of the present invention, and any device having the same function and effect can be realized by the present invention. It is included in the technical scope of the invention.

For example, in the above embodiment, an example in which the number of product storages and the number of evaporators is three has been described, but the present invention is not limited to this, and the number of product storages and evaporators as a whole. Any number may be used as long as it is two or more.

In the above embodiment, the first predetermined time is set to 5 minutes, and the second predetermined time is set to 10 minutes. However, the present invention is not limited to this and the first predetermined time is set to 10 minutes. The predetermined time and the second predetermined time may be a combination of other values. For example, an example in which the first predetermined time is 5 minutes and the second predetermined time is 5 minutes, and the first predetermined time is 1 minute and the second predetermined time is 2 minutes Good. Also, the second predetermined time is set to zero, and the first
Second time, which is the grace time until re-determination after the predetermined time
It is also possible to control so that the determination of the temperature difference between the evaporators is immediately restarted without taking the predetermined time. That is, the first
The predetermined time of 1 may be a real value that is not zero, and the second predetermined time may be a non-negative real value.

In the above embodiment, an example in which an ON (open) / OFF (closed) control type solenoid valve is used as the evaporator valve has been described, but the present invention is not limited to this, and the evaporator valve is not limited to this. An electronic expansion valve may be used as. Alternatively, instead of the stepping motor type electronic expansion valve, another type of variable opening type expansion valve may be adopted.

In the above embodiment, after the first predetermined time of 5 minutes has elapsed, the solenoid valve, which is the evaporator valve, which has been closed for 5 minutes is once opened (see step S5). ), The present invention is not limited to this. For example, even if the first predetermined time elapses,
If the temperature inside the already-cooled evaporator whose solenoid valve is closed is still lower than the upper limit temperature TU and cooling is not required, even if the solenoid valve is once opened in step S5, the "normal cooling control" in step S6 immediately after that is performed. Since it is unreasonable to close the valve immediately in ", in such a case, control may be performed such that the process proceeds to step S6 without executing step S5.

[0040]

As described above, according to the present invention,
Since the control means in the cooling device stops the supply of the refrigerant to the evaporator that is sufficiently cooled more than the other evaporators for at least the first predetermined time, the uncooled evaporator that is not yet well cooled is stopped. Sufficient refrigerant is supplied to enable rapid cooling of the uncooled evaporator.

Further, since the refrigerant is not wastefully supplied to the evaporator which has already been sufficiently cooled, energy is saved.

When the determination is made based on the temperature in the product storage, the product storage is not yet sufficiently cooled, but the temperature in the evaporator is sufficiently cooled, so that it can be left as it is. Even if the cooling of the product storage progresses with the passage of time, there is a case where wasteful cooling in the evaporator is further promoted, but in the case of the present invention, it is determined by the temperature in the evaporator. Therefore, such waste does not occur and accurate control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an automatic vending machine equipped with a cooling device according to an embodiment of the present invention.

FIG. 2 is a detailed block diagram showing a configuration of a cooling device in the vending machine shown in FIG.

FIG. 3 is a flowchart showing a control procedure in a controller of the cooling device of the vending machine shown in FIGS. 1 and 2.

FIG. 4 is a block diagram showing a configuration of a conventional example of a cooling device for a vending machine.

[Explanation of symbols]

 1 Cooling device 2 Cooling device main body 3 Controller 4a-4c Evaporator 5a-5c Temperature sensor 6,6a-6c Refrigerant pipe 7a-7c Solenoid valve 8 Distributor 9 Accumulator 10 Compressor 11 Condenser 12 Electronic expansion valve 20a-20c Product storage 51 Cooling Equipment 53a, 53b Capillary 54a, 54b Evaporator 56, 56a, 56b Refrigerant pipe 57a, 57b Solenoid valve 58 Distributor 59 Accumulator 60 Compressor 61 Condenser 100 Vending machine G Product

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyoshi Tajima 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. An evaporator forming a part of a refrigeration circuit is installed in each of a plurality of product storages, and a refrigerant is sent to each of the evaporators to evaporate the refrigerant in each of the evaporators. In a cooling device for a vending machine configured to cool a plurality of product storage boxes independently of each other, an evaporator valve that is provided in an inlet side refrigerant pipe of each evaporator and that can be opened or closed, and inside each evaporator. A temperature sensor inside the evaporator for detecting the temperature of the evaporator, a temperature sensor inside the storage for detecting the temperature inside the product storage, and a temperature difference between the evaporators detected by the temperature sensor inside the evaporator is determined. However, when the temperature difference between the evaporators becomes larger than a predetermined value, the control means for controlling the evaporator valve communicating with the evaporator having the lower temperature to be closed for the first predetermined time. And is equipped with Cooling device for an automatic vending machine. 2. An evaporator forming a part of a refrigeration circuit is installed in each of the plurality of product storages, and a refrigerant is sent to each of the evaporators to evaporate the refrigerant in each of the evaporators. In a cooling device for a vending machine configured to cool a plurality of product storage boxes independently of each other, an evaporator valve that is provided in an inlet side refrigerant pipe of each evaporator and that can be opened or closed, and inside each evaporator. And a temperature sensor for detecting the temperature of the evaporator, the temperature difference between the evaporators detected by the temperature sensors is determined, and if the temperature difference between the evaporators is greater than a predetermined value, the lower temperature The evaporator valve leading to the evaporator is closed for a first predetermined time, and the determination of the inter-evaporator temperature difference is stopped during a period from the elapse of the first predetermined time to the elapse of a second predetermined time. Control means for controlling to A cooling device for a vending machine, which is characterized in that