JPH0781773B2 - Cold storage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a cold storage for cooling a storage compartment.

2. Description of the Related Art A conventional refrigerator box consists of a heat-insulating outer box and a heat-conducting inner box 2
As a low-temperature storage without a heavy structure, in which a cooling device is arranged between the inner and outer boxes to cool the inner box and the inside thereof, Japanese Utility Model Laid-Open No. 60-93882 and Japanese Patent Laid-Open No. 60-152875. There is.

Is equipped with a heat insulating outer box and a heat conducting inner box with a fixed space fixedly installed, cool air is circulated in the space between the outer box and the inner box to cool the inner box, and the inner box is refrigerated. As a room, place the evaporator of the refrigerator for producing cold air and the fan for circulating the cold air in the cold air circulation space between the outer box and the inner box, and set the set other than the evaporator of the refrigerator in the outer box. The one equipped outside is disclosed.

On the other hand, a cool box main body, a closed cool chamber provided in the main body by blocking the surrounding cool air circulation space through a blocking wall made of a good heat conductor, and a cool air generator provided in the cool air circulation space, It is disclosed that a cool room is provided with an openable / closable inlet / outlet opening to the outside of the cold storage main body that is cut off from the cool air circulation space, and an openable / closable cold air inlet / cool air outlet opening in the cool air circulation space. .

Problems to be Solved by the Invention In the above-described technique, since the cold air circulation space and the refrigerating compartment are completely independent of each other, the double box structure allows the outside air to flow into the refrigerating compartment when the door is opened and closed. Since the temperature rises, it is necessary to cool the storage room rapidly, but since the structure of the double box is complete, the cooling in the refrigeration room is indirect regardless of the door opening / closing operation. There is a problem that rapid cooling cannot be performed.

On the other hand, in the above-mentioned technology, a part of the cool air flowing through the cool air circulation space is introduced into the cool chamber by opening the cool air outlet and the cool air suction port, and direct cooling is performed by directly flowing cool air into the cool chamber to cool it. Although it is possible to simultaneously perform both indirect cooling that indirectly cools the cold insulation chamber by the cold air that flows in the cold air circulation space, direct cooling only takes in part of the cold air that flows in the cold air circulation space. However, there is a problem that it takes a long time to cool the cold storage room because it is nothing more than a thing. In addition, since neither technology is configured to control the cooling operation based on the opening / closing operation of the door, it is not possible to suppress the temperature rise of the storage chamber due to the opening / closing operation, and to reduce the temperature to a predetermined temperature. There was a problem that it took time.

In view of this, the present invention provides a low temperature warehouse in which, in addition to being able to perform direct cooling and indirect cooling, the cooling system is switched according to the opening / closing operation of the door.

[Structure of Invention]

Means for Solving the Problems The present invention is directed to a heat-insulating outer box, a top wall and a bottom wall made of a good heat conductor with a space inside the outer box, and left and right side walls having a large number of air passage openings facing each other. A cold air circulation space formed by connecting each of them, a storage chamber formed by the respective walls and an outer box, a cooling device arranged in the cold air circulation space, and a cooling device having a blower, and A heat-insulating door for opening and closing articles which is openably and closably arranged in an outer box, and a flow path switching device for switching the cool air exiting the cooler to a flow path that allows the storage chamber to pass through or a flow path that does not pass through the storage chamber. A low-temperature storage comprising a control unit for forcibly switching the flow path by the flow path switching device to a flow path that passes through a storage chamber when the heat insulation door is opened.

Function When the door is opened when a storage item is put into or taken out of the storage chamber, the flow passage switching device is operated to form a passage through which cold air passes through the storage chamber to directly cool the storage chamber. As a result, the rise in the temperature of the storage chamber due to the opening of the door is suppressed, and the time required from the closing of the door to the return to the set temperature is shortened.

Embodiments Embodiments of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a low-temperature refrigerator such as a prefabricated refrigerator, which is a heat-insulating outer box 2 in which a heat-insulating panel is combined to form a box, and the outer box 2
Top wall 3 made of a good thermal conductor such as metal with a space inside
A storage chamber 1 formed by arranging the bottom wall 4 and a pair of left and right side walls 5 and 6 facing each other, and a cold air circulation space 11 surrounding the upper, lower, left and right surfaces of the storage chamber 10 ( That is, the front and rear surfaces of the storage room 10 are not covered by a duct as a space for circulating cold air). The front wall of the heat-insulating outer box 2 is provided with an opening 7 for putting in and taking out stored goods and a heat-insulating door 8 for closing the opening 7 so as to be openable and closable.

On the ceiling wall 3 that constitutes the cold air circulation space 11, a cooler represented by an evaporator that constitutes a part of the refrigeration cycle.
12 and a blower device 13 including a blower fan and a fan motor
And a cooling device 14 inside the refrigerator having
At the bottom of 14 (generally, a dew tray for receiving the dew generated during defrosting of the cooler 12 is provided at this bottom), the ceiling wall 3 is penetrated and the storage chamber 10 is passed through to the outside of the heat insulating outer box 2. A drainage device 15 such as a drainage pipe with a heater is connected so as to be drawn out. In the present embodiment, as the cooling device 14, the temperature control width is usually small around 0 ° C. (for example, about 10 ° C.), and the control accuracy is extremely high (for example, the setting accuracy is ± 0.5 ° C.).
Therefore, the one that is used for the temperature control of the ice temperature is adopted (the ice temperature means the temperature zone between the freezing point of the ice and the temperature just before the freezing of the food).

Further, the cold air circulation space 11 is the above space 11A as the first space above the ceiling wall 3, the cold air supply space 11B as the second space outside the right side wall 6, and the lower part as the third space below the bottom wall 4. It is composed of a space 11C and a cool air recovery space 11D as a fourth space on the outer side of the left side wall 5, and in this example, the cooling device 14
Is arranged in the upper space 11A.

20 is a flow path switching device which will be described later by opening / closing the heat insulating door 8.
FIG. 8 shows the configuration of the control unit 20, which is a control unit for controlling 33.

The control unit 20 includes a detection switch 21 that detects opening and closing of a door, and a timer 23 that operates when the detection switch 21 is closed.
And the timer contact 23 that closes when this timer 23 operates.
A and the first relay that is energized when the timer contact 23A is closed
24 and a contact 24A that is closed in conjunction with this first relay 24
And a b-contact 24B, a second relay 25 whose operation is controlled by the internal temperature control device 34, and an a-contact 25A and a b-contact 25B which are closed in conjunction with the second relay 25. The sensing switch 21, the timer 23, the timer contact 23A, the first relay 24 and the a-contact 24A form a self-holding circuit for the timer 23.
Reference numeral 6 is a limit switch having two contacts 26A and 26B which are interlocked so that when one is open, the other is closed. The drive device 36 rotates in one direction (direct cooling side) and the switching device 33 directly cools. The a-contact 26A is opened when it is moved, and the b-contact 26B is opened when the switching device 33 is turned to the indirect cooling state by rotating in the other direction (indirect cooling side). 22 is a power switch.

Reference numeral 30 designates the cold air supply space 11B in the cold air circulation space 11 inside and outside 2
It is a partition plate that divides into two passages (inner passage 31 and outer passage 32, respectively) and closes the lower end of the inner passage 31 to guide all the cool air introduced into the inner passage 31 to the storage chamber 10 side. A flow path switching device 33 for selectively introducing cool air into either one or both of the inner and outer passages 31 and 32 is arranged on the upper end side (that is, the air inlet side) of the partition plate 30 to supply the cool air supply space 11B. The flow of cold air inside can be switched.

The flow path switching device 33 detects the air temperature inside the storage chamber 10 or on the outlet side of the cooling device 14 and opens the cool air passage in accordance with the deviation between the detected temperature and the temperature set by the temperature setting means (not shown). A temperature control device 34 that sends a switching signal performs a switching operation, and a flow path switching member 35 that opens and closes the inner and outer passages 31 and 32, and a drive device 36 whose drive is controlled by a signal output from the temperature control device 34. A cam 37 which is rotated by deceleration by the drive device 36, and a flexible leaf spring whose one end is rotatably supported by the flow path switching member 35 and the other end is rotatably supported by the cam 37. And an operating plate 38 made of material.

One end of the operating plate 38 is rotatably connected to a bearing plate 40 extending vertically from the flow path switching member 35 by a shaft 41 in the front-rear direction, and the other end of the operating plate 38 is a surface of the cam 37 in a substantially vertical direction. It is rotatably connected by a horizontal shaft 42 so as to rotate along. Further, in order to connect in this way, the actuation plate 38 is formed with a twisted portion 43 twisted by about 90 degrees in the middle part, and one end and the other end of the actuation plate 38 are substantially
It will be held in a twisted positional relationship with a phase of 90 degrees, and the surface on one end side will be oriented in the left-right direction (this part
The surface on the other end side is oriented in the front-rear direction (this portion is referred to as front-rear surface portion 45). For this reason, the actuating plate should be
45 bends in the front-rear direction and absorbs the force, and when a force is applied in the left-right direction, the left and right surface portions 44 bend in the left-right direction and can absorb this force.

On the other hand, a large number of holes 50, 51 are formed in the left and right side walls 5, 6 as air passage openings, respectively. Further, since the front and rear surfaces of the storage chamber 10 are not covered by the ducts as the cold air circulation space, the heat of flow passing through the front and rear surfaces is directly stored in the storage chamber 10.
Because it will heat the storage room 10
For the purpose of generating cold air convection in the storage chamber in order to suppress the rise in the internal air temperature, a large number of holes 52 serving as cold air inlets are provided upstream of the flow path switching device 33 in the right side wall 6.
By forming the above, a small amount of cold air always flows into the storage chamber 10.

The cooling of the cold storage 1 in the above configuration will be described.

First, assuming that the storage room 10 is filled with food to be cooled, for example, food products such as fresh fish and vegetables, (1) the storage room 10 has a temperature higher than a desired temperature, so the interior of the storage room 10 is cooled. For temperature control device
The drive device 36 is operated by 34 to switch the cold air passage of the cold air supply space 11B formed by the flow passage switching device 33 to the storage chamber side, that is, the position where the outer passage 32 is closed and the inner passage 31 is opened. Therefore, the air cooled by the cooling device 14 (referred to as cold air) flows from the upper space 11A to the inside passage 3
The first cold air circulation path P (1) is introduced into the storage chamber 10 through the hole 51 in the right side wall 6 and returns to the air suction side of the cooling device 14 from the cold air recovery space 11D through the hole 50 in the left side wall 5. See the solid arrow in Fig. 2). The temperature in the storage chamber is gradually decreased by the cooling by the path P (hereinafter referred to as direct cooling because cold air directly passes through the storage chamber to cool the storage chamber).

(2) When the temperature inside the storage chamber gradually decreases to a predetermined temperature or less due to the direct cooling by the first cool air circulation path P, the drive unit 36 is operated by the control unit 34 to set the flow path. The switching device 33 is switched to the non-storage room side, that is, to a position where the outer passage 32 is opened and the inner passage 31 is closed. Therefore, the cool air exiting the cooling device 14 enters the outer passage 32 from the upper space 11A, returns to the air suction side of the cooling device 14 through the lower space 11C and the cool air recovery space 11D, and is returned to the second cool air circulation path Q (see FIG. 1). Take the broken arrow). By the cold air circulation by the second cold air circulation path Q, the ceiling wall 3 and the partition plate 30
The bottom surface 4 and the left side wall 5 are cooled respectively, and the air in the storage room is cooled by natural convection by the cooled walls and plates. In other words, the inside of the storage chamber 10 is indirectly cooled (hereinafter referred to as indirect cooling).

(3) When the temperature inside the storage chamber gradually decreases due to the indirect cooling by the cool air circulation path Q and drops below the desired temperature set by the temperature setting means (not shown), the cooling device 14 operates the thermostat. A cycle operation or a minimum capacity operation (the latter in this example) is switched to operate so as to maintain the temperature in the storage chamber at a desired temperature.

(4) The temperature in the storage chamber rises due to an increase in the heat load due to the inflow of outside air or disturbance due to the opening / closing operation of the heat insulating door 8. In order to minimize this, the detection switch 21 that detects the opening and closing of the door is turned on when the door is opened (see the control circuit diagram below), the delay timer 23 is activated, and the
A is closed, the first relay 24 is energized, and it is interlocked with a
The contact 24A is closed, the b contact 24B is opened, the drive device 36 is driven, and the flow path switching device 33 is directly cooled (cool air is supplied to the inside passage).
31 side to introduce). Here, even when the storage of the stored goods is completed and the door is closed, the delay timer 23 holds the first relay 24 by itself and maintains the same state for a certain time (the time measured by the timer 23). Even if the delay timer 23 expires, if the temperature inside the storage chamber is higher than a certain set temperature, the second relay 25 is energized due to the operation of the temperature control unit 34, and the a-contact that interlocks with the second relay 25. 25A closed, b contact 2
Since 5B remains open, it remains in direct cooling. After that, when the temperature in the storage chamber drops and falls below a predetermined temperature, the second relay 25 is disconnected, the b contact 25B is closed, and the drive device 36 causes the flow path switching device 33 to be in an indirectly cooled state (cold air outside). It is moved to the side of the passage 32).

According to the above configuration, the temperature in the storage chamber can be maintained at a desired temperature by repeating the cooling process of (1) to (3), and the temperature rise due to opening and closing of the door can be performed by (4). It can be suppressed to a minimum.

As described above in detail, according to the present invention, although the temperature in the storage chamber rises due to an increase in heat load due to external air inflow or disturbance accompanying the opening / closing operation of the heat insulating door, it is detected that the door is opened,
The flow path switching device is moved regardless of the temperature in the refrigerator to guide the cool air to the inner passage so that the cool air flows into the storage chamber. As a result, the invasion of outside air into the storage chamber can be reduced, and the temperature rise can be suppressed to a minimum.

In addition, even if the goods (stored goods) are put in and out of the storage room and the door is closed, the flow path switching device does not operate immediately, and the self-holding by the delay timer and the temperature for controlling the internal temperature After both the set values (time and temperature) of and are satisfied by the control thermo, they are activated to guide cold air to the outside passage to indirectly cool and keep cool. After the product is put in or taken out, there is a large amount of invasion of outside air and the heat load of the product, and it is necessary to perform rapid cooling by direct cooling.

From the above, the intrusion of heat load when opening and closing the door is reduced, the temperature rise inside the warehouse and the temperature rise of the goods are suppressed, and the direct cooling and indirect cooling after opening and closing are automatically controlled with respect to time and temperature. It is possible to rapidly cool the storage chamber and goods (stored goods), which is performed in 1.

〔The invention's effect〕

As described above in detail, according to the present invention, although the temperature in the storage chamber rises due to an increase in heat load due to external air inflow or disturbance accompanying the opening / closing operation of the heat insulating door, it is detected that the door is opened,
The flow path switching device is moved regardless of the temperature in the refrigerator to guide the cool air to the inner passage so that the cool air flows into the storage chamber. As a result, the invasion of outside air into the storage chamber can be reduced, and the temperature rise can be suppressed to a minimum.

For this reason, the intrusion of heat load when opening and closing the door is reduced, the temperature rise inside the warehouse and the temperature rise of the goods are suppressed, and direct cooling and indirect cooling after opening and closing are automatically performed with time and temperature control. , It is possible to rapidly cool the storage chamber and goods (storage).

[Brief description of drawings]

Each drawing shows one embodiment of the present invention, FIG. 1 is a front view of a low temperature compartment in a partially cutaway state showing a cold air circulation path during indirect cooling, and FIG. 2 is a cold air circulation path during direct cooling. Figure 1 correspondence diagram,
FIG. 3 is a plan view of the low temperature cabinet with the top plate of the heat insulation outer box removed.
FIG. 4 is a sectional view taken along the line AA of FIG. 1, FIG. 5 is an enlarged view of a B portion of FIG. 1, FIG. 6 is an enlarged view of a C portion of FIG. 2, and FIG. 7 is a low temperature chamber for indirect cooling. 8 is a timing chart showing an operating state and a temperature change when the door is opened, and FIG. 8 is a circuit diagram of the control unit. 1 ... Low temperature chamber, 2 ... Insulated outer box, 3 ... bottom wall, 4 ... bottom wall, 5 ... left side wall, 6 ... right side wall, 8 ... insulation door, 10 ...
… Storage room, 11 …… Cold air circulation space, 12 …… Cooler, 13 ……
Blower, 14 ... Cooling device, 20 ... Control unit, 33 ... Flow path switching device.

Claims (1)

[Claims] 1. A heat-insulating outer box, a ceiling wall and a bottom wall made of a good heat conductor, which are spaced apart from each other inside the outer box, and left and right side walls having a large number of air passage openings facing each other, which are connected to each other. A cold air circulation space, a storage chamber formed by each wall and an outer box, a cooling device having a cooler and a blower arranged in the cold air circulation space, and an openable and closable arrangement in the outer box. A heat-insulating door for loading and unloading articles, a flow-path switching device for switching the cool air that has flowed out of the cooler between a flow path that passes through the storage chamber and a flow path that does not pass through the storage chamber, and the heat-insulating door is opened. A low-temperature storage comprising a control unit for forcibly switching the flow path by the flow path switching device to a flow path that passes through the storage chamber.