Product storage device

Abstract

To prevent damage to products due to frost formation on the evaporator. [Solution] A product storage device comprising a storage compartment 11 formed facing the outlet 10a of the main body of the device 10, an air passage 12 formed to communicate with the storage compartment 11 through an intake port 13a and an outlet port 14a formed in the walls 13 and 14 of the storage compartment 11 facing each other, a blower fan 22 that circulates air between the storage compartment 11 and the air passage 12 through the intake port 13a and the outlet port 14a, and an evaporator 21d that cools the air passing through the air passage 12, wherein the device comprises an intake temperature detection unit 16 that detects the intake temperature, which is the temperature of the air drawn into the air passage 12 through the intake port 13a, and a control unit 40 that increases the amount of air blown by the blower fan 22 when the magnitude of the increase in the intake temperature per unit time detected by the intake temperature detection unit 16 exceeds a predetermined reference value.

Description

Technical Field

[0001] The present invention relates to an improvement of a commodity storage device, and more particularly to an improvement of a commodity storage device for cooling commodities to be stored.

Background Art

[0002] Conventionally, a commodity storage device as an open flat ice case for storing commodities such as ice cream in a retrievable state is known, and this commodity storage device includes a device main body. The device main body is a rectangular parallelepiped heat insulating housing having an outlet formed on the upper surface, and has a storage chamber provided in a manner facing the outlet and an air passage communicating with the storage chamber through a suction port and a blowout port. In this air passage, a blower fan for circulating air between the storage chamber and the air passage and an evaporator for cooling the passing air are provided, and the air cooled by the evaporator is sent to the storage chamber, whereby the commodities stored in the storage chamber are cooled (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=3G]] By the way, in the above commodity storage device, it is known that frosting occurs on the evaporator by cooling the commodities. Such frosting inhibits the passage of air around the evaporator, and as a result, causes a decrease in the amount of air circulation between the storage chamber and the air passage.

[0005] Such a decrease in the amount of air circulation, combined with the fact that the storage chamber faces the outlet, induces the introduction of outside air, inhibits the cooling of the commodities, and may damage the commodities.

[0006] In view of the above circumstances, the present invention aims to provide a product storage device that can prevent damage to products due to frost formation on the evaporator. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a product storage device comprising: a storage compartment formed in such a manner that it faces an outlet of the main body of the device; an air passage formed in such a manner that it communicates with the storage compartment through an intake port and an outlet formed in the walls of the storage compartment that are opposite to each other; a blower fan that circulates air between the storage compartment and the air passage through the intake port and the outlet; and an evaporator that cools the air passing through the air passage, wherein the product storage device cools the products stored in the storage compartment so that they can be taken out through the outlet, and further comprises: an intake temperature detection means for detecting the intake temperature, which is the temperature of the air drawn into the air passage through the intake port; and a control unit that increases the amount of air blown by the blower fan when the magnitude of the increase in the intake temperature per unit time detected by the intake temperature detection means exceeds a predetermined reference value.

[0008] Furthermore, the present invention relates to a product storage device comprising: a storage compartment formed in such a manner that it faces an outlet of the main body of the device; an air passage formed in such a manner that it communicates with the storage compartment through an intake port and an outlet formed in the walls of the storage compartment that face each other; a blower fan that circulates air between the storage compartment and the air passage through the intake port and the outlet; and an evaporator that cools the air passing through the air passage, wherein the product storage device cools the products stored in the storage compartment so that they can be taken out through the outlet, and further comprises: an intake temperature detection means for detecting the intake temperature, which is the temperature of the air drawn into the air passage through the intake port; an external temperature detection means for detecting the external temperature, which is the temperature of the air outside the main body of the device; and a control unit that increases the amount of air blown by the blower fan when the magnitude of the difference between the external temperature detected by the external temperature detection means and the intake temperature detected by the intake temperature detection means is less than or equal to a preset value.

[0009] Furthermore, the present invention is characterized in that, in the above-mentioned product storage device, the control unit switches to a defrosting operation to remove frost adhering to the evaporator and resets the airflow rate of the blower fan when the amount of air blown by the blower fan exceeds a preset allowable value. [Effects of the Invention]

[0010] According to the present invention, the control unit increases the amount of air blown by the blower fan when the magnitude of the increase in the suction temperature per unit time detected by the suction temperature detection means exceeds a predetermined reference value. This suppresses a decrease in the amount of air circulating between the storage compartment and the air passage, and has the effect of preventing damage to goods due to frost formation on the evaporator.

[0011] Furthermore, according to the present invention, when the control unit increases the amount of air blown by the blower fan when the difference between the external temperature detected by the external temperature detection means and the suction temperature detected by the suction temperature detection means falls below a preset value, it suppresses a decrease in the amount of air circulating between the storage compartment and the air passage, and has the effect of preventing damage to products due to frost formation on the evaporator. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view showing the external configuration of a product storage device according to Embodiment 1 of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional side view showing the internal structure of a product storage device according to Embodiment 1 of the present invention. [Figure 3] Figure 3 is a schematic block diagram showing a characteristic control system of a product storage device according to Embodiment 1 of the present invention. [Figure 4] Figure 4 is a flowchart showing the processing details of the blower fan drive control performed by the control unit shown in Figure 3. [Figure 5] Figure 5 is a schematic block diagram showing a characteristic control system of a product storage device according to Embodiment 2 of the present invention. [Figure 6]Figure 6 is a flowchart showing the processing details of the blower fan drive control performed by the control unit shown in Figure 5. [Modes for carrying out the invention]

[0013] A preferred embodiment of the product storage device according to the present invention will be described in detail below with reference to the attached drawings.

[0014] <Embodiment 1> Figure 1 is a perspective view showing the external configuration of a product storage device according to Embodiment 1 of the present invention, Figure 2 is a schematic cross-sectional side view showing the internal structure of a product storage device according to Embodiment 1 of the present invention, and Figure 3 is a schematic block diagram showing the characteristic control system of a product storage device according to Embodiment 1 of the present invention.

[0015] The product storage device illustrated here is, for example, an open, flat-type ice cream case installed in stores such as convenience stores and supermarkets, which stores products such as ice cream in a way that allows them to be easily removed, and it comprises a device body 10.

[0016] The main body of the device 10 is a rectangular thermal insulation enclosure in which the width (left-right direction) is larger than the depth (front-back direction), and has an outlet 10a on its top surface. Inside the main body of the device 10, there is a storage compartment 11 and an air passage 12, and a cooling unit 20 and a blower fan 22 are provided.

[0017] The storage compartment 11 is a room defined in such a manner that it faces the outlet 10a. Of the long front wall 13 and rear wall 14 that extend along the left-right direction defining the storage compartment 11 and face each other, an intake port 13a is formed in the upper part of the front wall 13, and an outlet port 14a is formed in the upper part of the rear wall 14.

[0018] The suction port 13a is an opening for sucking the air inside the storage chamber 11 and extends along the left - right direction of the storage chamber 11. The blow - out port 14a is an opening for blowing air into the storage chamber 11. This blow - out port 14a extends along the left - right direction of the storage chamber 11.

[0019] The air passage 12 is a passage for air from the suction port 13a to the blow - out port 14a. This air passage 12 is configured in a manner that the front - side passage 12a which communicates with the suction port 13a and is outside and in front of the storage chamber 11, the lower - side passage 12b which is outside and below the storage chamber 11, and the rear - side passage 12c which is outside and behind the storage chamber 11 and communicates with the above - mentioned blow - out port 14a are connected to each other.

[0020] The cooling unit 20 is configured to include a refrigerant circuit 21. The refrigerant circuit 21 is formed by sequentially connecting a compressor 21a, a condenser 21b, an expansion mechanism 21c, and an evaporator line 21d with refrigerant pipes, and refrigerant is enclosed inside.

[0021] The compressor 21a is installed in the machine room 15 in the lower area of the storage chamber and the air passage inside the apparatus main body 10. This compressor 21a is a driving device of the cooling unit 20 that sucks refrigerant and compresses the sucked refrigerant by being driven at a constant rotational speed in response to a command given from a control unit 40 (not shown) which is a driving source such as a motor.

[0022] The condenser 21b is installed in the machine room 15 on the front - side of the compressor 21a. This condenser 21b condenses the refrigerant compressed by the compressor 21a. The expansion mechanism 21c is constituted by, for example, an electronic expansion valve, and its opening degree is adjusted in response to an opening - degree command given from the control unit \alpha. This expansion mechanism 21c adiabatically expands the refrigerant condensed by the condenser 21b.

[0023] The evaporator 21d is installed at any point in the lower passage 12b of the air passage 12. This evaporator 21d cools the surrounding air by evaporating the refrigerant supplied from the expansion mechanism 21c. The refrigerant evaporated in this evaporator 21d is drawn into the compressor 21a.

[0024] The blower fan 22 is installed in the lower passage 12b. This blower fan 22 is driven by a blower fan drive unit 22a, which is a drive source such as a motor, driven by a command given by the control unit 40. When the blower fan 22 is driven by rotation, it draws in air from inside the storage compartment 11 through the intake port 13a, sends the drawn-in air through the air passage 12 in the order of the front passage 12a, the lower passage 12b, and the rear passage 12c to the outlet 14a, and blows it back into the storage compartment 11 through the outlet 14a, thereby circulating air between the inside of the storage compartment 11 and the air passage 12.

[0025] The storage unit 11 contains multiple wire baskets 30. These wire baskets 30 are stored in a row, front to back, and also stacked on top of each other. The wire baskets 30 are for storing goods. As a result, goods are stored in the storage unit 11.

[0026] In addition to the above configuration, the product storage device according to this embodiment 1 also includes a suction temperature detection unit 16 and a control unit 40.

[0027] The suction temperature detection unit 16 is located near the suction port 13a. This suction temperature detection unit 16 periodically detects the suction temperature, which is the temperature of the air drawn into the air passage 12 through the suction port 13a, and outputs the detection result as a signal to the control unit 40 each time.

[0028] The control unit 40 is a control means that comprehensively controls the operation of each part of the product storage device according to the programs and data stored in the storage unit 41. This control unit 40 includes an input processing unit 40a, a calculation processing unit 40b, a comparison and judgment processing unit 40c, and a fan drive processing unit 40d.

[0029] The input processing unit 40a receives signals from the suction temperature detection unit 16. The calculation processing unit 40b calculates the increase (slope) per unit time for the suction temperature periodically input from the suction temperature detection unit 16 via the input processing unit 40a.

[0030] The comparison judgment processing unit 40c determines whether the magnitude of the slope calculated through the calculation processing unit 40b is equal to or greater than the reference value contained in the reference value information 41a read from the storage unit 41. Here, the reference value is stored in the storage unit 41 as reference value information 41a and is a threshold value used to determine whether frost formation on the evaporator 21d may adversely affect the cooling of goods in the storage compartment 11.

[0031] Let me explain this adverse effect. As frost buildup progresses on the evaporator 21d, the amount of air circulating decreases even when the blower fan 22 is rotating at a constant speed due to clogging caused by the frost. As a result, the cooling of the product is hindered by the outside air flowing in through the outlet 10a.

[0032] Incidentally, the memory unit 41 stores not only the reference value information 41a but also the permissible value information 41b. The permissible value information 41b is information that includes the permissible value. The permissible value is a value close to the upper limit of the airflow rate from the blower fan 22, and is a threshold for determining whether or not to perform defrosting operation.

[0033] The fan drive processing unit 40d sends drive commands to the blower fan drive unit 22a that increase or decrease the rotational speed, as well as drive stop commands. The fan drive processing unit 40d also determines whether the airflow rate exceeds an allowable value when the airflow rate is increased by increasing the rotational speed.

[0034] Furthermore, the control unit 40 may be implemented, for example, by causing a processing unit such as a CPU (Central Processing Unit) to execute a program, i.e., by software; by hardware such as an IC (Integrated Circuit); or by using a combination of software and hardware.

[0035] In a product storage device having the above configuration, the control unit 40 can cool the products stored in the storage compartment 11 (products contained in the wire basket 30) as follows by giving a drive command to the compressor drive unit to drive the compressor 21a at a predetermined rotational speed, and by giving a drive command to the blower fan drive unit 22a to drive the blower fan 22 at a predetermined rotational speed (initial rotational speed).

[0036] In other words, the compressor 21a draws in and discharges refrigerant, causing the refrigerant to circulate through the refrigerant circuit 21 in the order of compressor 21a → condenser 21b → expansion mechanism 21c → evaporator 21d. Furthermore, the blower fan 22 drives air drawn into the air passage 12 through the intake port 13a and blown out into the storage compartment 11 through the outlet port 14a, thus circulating air between the storage compartment 11 and the air passage 12. As a result, the air cooled around the evaporator 21d is blown into the storage compartment 11, cooling the air stored in the storage compartment 11.

[0037] In a product storage device that performs a cooling operation to cool products in this manner, the following blower fan drive control is performed. Figure 4 is a flowchart showing the processing details of the blower fan drive control performed by the control unit 40 shown in Figure 3.

[0038] In the blower fan drive control, the control unit 40 waits for input of the suction temperature from the suction temperature detection unit 16 via the input processing unit 40a (step S101).

[0039] When the suction temperature is input from the suction temperature detection unit 16 via the input processing unit 40a (step S101: Yes), the control unit 40 calculates the amount of increase (slope) of the suction temperature per unit time via the calculation processing unit 40b (step S102).

[0040] The control unit 40, which has calculated the slope, reads reference value information 41a from the storage unit 41 and determines whether the magnitude of the slope is greater than or equal to the reference value through the comparison judgment processing unit 40c (step S103).

[0041] If the magnitude of the slope is less than the standard value (step S103: No), the control unit 40 maintains the airflow rate of the blower fan 22, assuming that the amount of frost on the evaporator 21d is within the acceptable range (step S104), and then returns to the previous step to terminate the current process.

[0042] On the other hand, if the magnitude of the inclination is greater than or equal to the standard value (step S103: Yes), the control unit 40 considers the amount of frost on the evaporator 21d to have exceeded the allowable range and sends a drive command to the blower fan drive unit 22a via the fan drive processing unit 40d that increases the rotational speed, thereby increasing the amount of air blown by the blower fan 22 by a predetermined amount (step S105). This makes it possible to suppress a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12 even if the amount of frost on the evaporator 21d increases.

[0043] Having increased the airflow rate of the blower fan 22 in this manner, the control unit 40 reads the allowable value information 41b from the storage unit 41 and determines whether the airflow rate is equal to or greater than the allowable value (step S106).

[0044] If the airflow rate is below the allowable value (step S106: No), the control unit 40 returns to the previous step without performing the process described later and terminates the current process.

[0045] On the other hand, if the airflow rate is above the allowable value (step S106: Yes), the control unit 40 switches to defrosting operation, sends a drive stop command to the compressor drive unit, energizes the defrost heater (not shown) located near the evaporator 21d, and sends a drive command at the initial rotation speed to the blower fan drive unit 22a via the fan drive processing unit 40d, thereby resetting the airflow rate of the blower fan 22 (step S107), and then returns to the previous step to end the current process. This removes the frost adhering to the evaporator 21d.

[0046] Furthermore, after a predetermined defrosting time has elapsed since the start of defrosting operation, the control unit 40 sends a drive command to the compressor drive unit, thereby transitioning to a cooling operation to cool the products in the storage compartment 11.

[0047] As described above, according to the product storage device of Embodiment 1 of the present invention, the control unit 40 increases the amount of air blown by the blower fan 22 when the magnitude of the increase (slope) of the suction temperature per unit time detected by the suction temperature detection unit 16 exceeds a predetermined reference value. This suppresses a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12, and prevents damage to products due to frost formation on the evaporator 21d.

[0048] In particular, with the above-described product storage device, the amount of air blown by the blower fan 22 is adjusted based on the increase in the intake temperature per unit time. This allows for early detection of the inflow of outside air caused by a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12, thereby improving the accuracy of determining frost formation on the evaporator 21d. While it is also possible to determine frost formation on the evaporator 21d by detecting the amount of air blown out at the outlet 14a, the amount of air blown out at the outlet 14a is easily affected by the passage configuration of the air passage 12, making it difficult to detect the inflow of outside air. Therefore, there is a risk that the products in the storage compartment 11 may be damaged by outside air.

[0049] Furthermore, according to the product storage device, when the airflow rate of the blower fan 22 exceeds a preset allowable value, the control unit 40 switches to a defrosting operation to remove frost attached to the evaporator 21d and resets the airflow rate of the blower fan 22. This allows for effective removal of frost attached to the evaporator 21d and suppresses damage to the products.

[0050] <Embodiment 2> Figure 5 is a schematic block diagram showing a characteristic control system of a product storage device according to Embodiment 2 of the present invention. Note that components identical to those of the product storage device according to Embodiment 1 described above are denoted by the same reference numerals, and their descriptions are omitted.

[0051] The product storage device illustrated here is, for example, an open, flat-type ice case installed in stores such as convenience stores and supermarkets, which stores products such as ice cream in a way that allows them to be easily removed. It is equipped with an intake temperature detection unit 16, an external temperature detection unit 17, and a control unit 50.

[0052] The external temperature detection unit 17 is located outside the main body of the device 10. This external temperature detection unit 17 is an external temperature detection means that periodically detects the external temperature, which is the temperature of the air outside the main body of the device 10, and outputs the detection result as a signal to the control unit 50 each time.

[0053] The control unit 50 is a control means that comprehensively controls the operation of each part of the product storage device according to the programs and data stored in the storage unit 51. This control unit 50 includes an input processing unit 50a, a calculation processing unit 50b, a comparison and judgment processing unit 50c, and a fan drive processing unit 50d.

[0054] The input processing unit 50a receives signals from the suction temperature detection unit 16 and the external temperature detection unit 17. The calculation processing unit 50b calculates the difference between the external temperature and the suction temperature from the suction temperature periodically obtained from the suction temperature detection unit 16 via the input processing unit 50a and the external temperature periodically obtained from the external temperature detection unit 17 via the input processing unit 50a.

[0055] The comparison judgment processing unit 50c determines whether the magnitude of the difference calculated through the calculation processing unit 50b is less than or equal to the set value contained in the set value information 51a read from the storage unit 51. Here, the set value is stored in the storage unit 51 as set value information 51a and is a threshold value used to determine whether frost formation on the evaporator 21d may adversely affect the cooling of goods in the storage compartment 11.

[0056] Let me explain this adverse effect. As frost buildup progresses on the evaporator 21d, the amount of air circulating decreases even when the blower fan 22 is rotating at a constant speed due to clogging caused by the frost. As a result, the cooling of the product is hindered by the outside air flowing in through the outlet 10a.

[0057] Incidentally, the memory unit 51 stores not only the setting value information 51a mentioned above, but also the allowable value information 51b. The allowable value information 51b is information that includes an allowable value. The allowable value is a value close to the upper limit of the airflow rate from the blower fan 22, and is a threshold for determining whether or not to perform defrosting operation.

[0058] The fan drive processing unit 50d sends drive commands to the blower fan drive unit 22a that increase or decrease the rotational speed, as well as drive stop commands. The fan drive processing unit 50d also determines whether the airflow rate exceeds an allowable value when the airflow rate is increased by increasing the rotational speed.

[0059] Furthermore, the control unit 50 may be implemented, for example, by causing a processing unit such as a CPU (Central Processing Unit) to execute a program, i.e., by software; by hardware such as an IC (Integrated Circuit); or by using a combination of software and hardware.

[0060] In a product storage device having the above configuration, the control unit 50 can cool the products stored in the storage compartment 11 (products contained in the wire basket 30) as follows by giving a drive command to the compressor drive unit to drive the compressor 21a at a predetermined rotational speed, and by giving a drive command to the blower fan drive unit 22a to drive the blower fan 22 at a predetermined rotational speed (initial rotational speed).

[0061] In other words, the compressor 21a draws in and discharges refrigerant, causing the refrigerant to circulate through the refrigerant circuit 21 in the order of compressor 21a → condenser 21b → expansion mechanism 21c → evaporator 21d. Furthermore, the blower fan 22 drives air drawn into the air passage 12 through the intake port 13a and blown out into the storage compartment 11 through the outlet port 14a, thus circulating air between the storage compartment 11 and the air passage 12. As a result, the air cooled around the evaporator 21d is blown into the storage compartment 11, cooling the air stored in the storage compartment 11.

[0062] In a product storage device that performs a cooling operation to cool products in this manner, the following blower fan drive control is performed. Figure 6 is a flowchart showing the processing details of the blower fan drive control performed by the control unit 50 shown in Figure 5.

[0063] In the blower fan drive control, the control unit 50 waits for input of the suction temperature from the suction temperature detection unit 16 and the external temperature from the external temperature detection unit 17 via the input processing unit 50a (step S201).

[0064] When the suction temperature and external temperature are input through the input processing unit 50a (step S201: Yes), the control unit 50 calculates the difference between the external temperature and the suction temperature through the calculation processing unit 50b (step S202).

[0065] The control unit 50, having calculated the difference, reads the set value information 51a from the storage unit 51 and determines through the comparison judgment processing unit 50c whether the magnitude of the difference is less than or equal to the set value (step S203).

[0066] If the magnitude of the difference exceeds the set value (step S203: No), the control unit 50 maintains the airflow rate of the blower fan 22, assuming that the amount of frost on the evaporator 21d is within an acceptable range (step S204), and then returns to the previous step to terminate the current process.

[0067] On the other hand, if the magnitude of the difference is less than or equal to the set value (step S203: Yes), the control unit 50 considers the amount of frost on the evaporator 21d to have exceeded the allowable range and sends a drive command to the blower fan drive unit 22a via the fan drive processing unit 50d that increases the rotational speed, thereby increasing the amount of air blown by the blower fan 22 by a predetermined amount (step S205). This makes it possible to suppress a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12 even if the amount of frost on the evaporator 21d increases.

[0068] Having increased the airflow rate of the blower fan 22 in this manner, the control unit 50 reads the allowable value information 51b from the storage unit 51 and determines whether the airflow rate is equal to or greater than the allowable value (step S206). If the airflow rate is less than the allowable value (step S206: No), the control unit 50 returns to the previous step without performing the processing described later and terminates the current process.

[0069] On the other hand, if the airflow rate is above the allowable value (step S206: Yes), the control unit 50 switches to defrosting operation, sends a drive stop command to the compressor drive unit, energizes the defrost heater (not shown) located near the evaporator 21d, and sends a drive command at the initial rotation speed to the blower fan drive unit 22a via the fan drive processing unit 50d, thereby resetting the airflow rate of the blower fan 22 (step S207), and then returns to the previous step to end the current process. This removes the frost adhering to the evaporator 21d.

[0070] Furthermore, after a predetermined defrosting time has elapsed since the start of defrosting operation, the control unit 50 sends a drive command to the compressor drive unit, thereby transitioning to a cooling operation to cool the products in the storage compartment 11.

[0071] As described above, according to the product storage device of Embodiment 2 of the present invention, the control unit 50 increases the amount of air blown by the blower fan 22 when the difference between the external temperature and the intake temperature falls below a preset value. This suppresses a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12, and prevents damage to products due to frost formation on the evaporator 21d.

[0072] In particular, with the above-described product storage device, the amount of air blown by the blower fan 22 is adjusted based on the difference between the external temperature and the intake temperature. This allows for early detection of the inflow of external air caused by a decrease in the amount of air circulating between the storage compartment 11 and the air passage 12, thereby improving the accuracy of determining frost formation on the evaporator 21d. While it is also possible to determine frost formation on the evaporator 21d by detecting the amount of air blown out at the outlet 14a, the amount of air blown out at the outlet 14a is easily affected by the passage configuration of the air passage 12, making it difficult to detect the inflow of external air. Therefore, there is a risk that the products in the storage compartment 11 may be damaged by external air.

[0073] Furthermore, according to the above-described product storage device, when the airflow rate of the blower fan 22 exceeds a preset allowable value, the control unit 50 switches to a defrosting operation to remove frost attached to the evaporator 21d and resets the airflow rate of the blower fan 22. This allows for effective removal of frost attached to the evaporator 21d and suppresses damage to the products.

[0074] Although preferred embodiments 1 and 2 of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made.

[0075] In the above-described embodiment 2, the external temperature was detected by the external temperature detection unit 17. However, in the present invention, the set temperature of the store where the product storage device is installed may be used as the external temperature. Alternatively, the store's air conditioning system and the product storage device may be coordinated, and the set temperature provided by the air conditioning system may be used as the external temperature.

[0076] Although not mentioned in Embodiments 1 and 2 described above, the present invention may include an outlet temperature detection means for detecting the outlet temperature, which is the temperature of the air that has passed through the evaporator, and the amount of frost on the evaporator may be estimated using the intake temperature, external temperature, and outlet temperature, and the amount of air blown by the blower fan may be adjusted.

[0077] Although not mentioned in Embodiments 1 and 2 described above, in the present invention, a regression equation may be created using the external temperature as the cause and the intake temperature as the effect, taking into account the installation location of the product storage device in the store and the degree of interference with the air conditioning system. Based on this regression equation, the amount of frost on the evaporator may be estimated and the airflow rate of the blower fan may be adjusted. [Explanation of symbols]

[0078] 10...Main unit, 11...Storage compartment, 12...Air passage, 13a...Intake port, 14a...Outlet port, 16...Intake temperature detection unit, 17...External temperature detection unit, 20...Cooling unit, 21...Refrigerant circuit, 21a...Compressor, 21b...Condenser, 21c...Expansion mechanism, 21d...Evaporator, 22...Blower fan, 22a...Blower fan drive unit, 40,50...Control unit, 40a,50a...Input processing unit, 40b,50b...Calculation processing unit, 40c,50c...Comparison judgment processing unit, 40d,50d...Fan drive processing unit, 41,51...Storage unit, 41a...Reference value information, 41b,51b...Allowable value information, 51a...Set value information.

Claims

1. A storage compartment formed in such a manner that it faces the outlet of the main body of the device, An air passage is formed in such a manner that it communicates with the storage compartment through an intake port and an exhaust port formed in the walls of the storage compartment that are opposite to each other, A fan that circulates air between the storage compartment and the air passage through the aforementioned intake port and outlet port, An evaporator that cools the air passing through the aforementioned air passage and Equipped with, A product storage device that cools products stored in the storage compartment so that they can be removed through the outlet, A suction temperature detection means for detecting the suction temperature, which is the temperature of the air drawn into the air passage through the suction port, When the magnitude of the increase in the suction temperature per unit time detected by the suction temperature detection means exceeds a predetermined reference value, the control unit increases the amount of air blown by the blower fan. A product storage device characterized by being equipped with the following features.

2. A storage compartment formed in such a manner that it faces the outlet of the main body of the device, An air passage is formed in such a manner that it communicates with the storage compartment through an intake port and an exhaust port formed in the walls of the storage compartment that are opposite to each other, A fan that circulates air between the storage compartment and the air passage through the aforementioned intake port and outlet port, An evaporator that cools the air passing through the aforementioned air passage and Equipped with, A product storage device that cools products stored in the storage compartment so that they can be removed through the outlet, A suction temperature detection means for detecting the suction temperature, which is the temperature of the air drawn into the air passage through the suction port, An external temperature detection means for detecting the external temperature, which is the temperature of the air outside the main body of the device, A control unit increases the amount of air blown by the blower fan when the difference between the external temperature detected by the external temperature detection means and the suction temperature detected by the suction temperature detection means falls below a preset value. A product storage device characterized by being equipped with the following features.

3. The product storage device according to claim 1 or 2, characterized in that the control unit, when the amount of air blown by the blower fan exceeds a preset allowable value, switches to a defrosting operation to remove frost adhering to the evaporator and resets the amount of air blown by the blower fan.

Images