JP2016017643A - Open show case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fast correction of disturbance in temperature distribution generated within a display room.SOLUTION: This invention relates to an open show case in which cold air generated through a cooler 33 under driving of refrigerator fans 35 is blown out from a cold air blowing-out port 27 toward a cold air suction port 28 to form an air curtain AC. A plurality of refrigerator fans 35 are arranged to be spaced apart in a width direction of a case main body 20. There are provided the same number of temperature sensors 37 for use in detecting refrigerator temperatures individually at a plurality of locations spaced apart in a width direction at a display room 30 and a fan driving control device for individually controlling a rotational speed of each of the refrigerator fans 35 to cause each of the detected temperatures to become substantially a constant value on the basis of the detected temperature of each of the temperature sensors 37.SELECTED DRAWING: Figure 3

Description

  The technique disclosed by this specification is related with an open showcase.

  As an example of a conventional open showcase, one described in Patent Document 1 below is known. This is provided with a case body having an opening on the front surface and an inside as a display chamber, a cool air circulation duct is formed on the peripheral wall of the case body, and a cooler and an internal fan are provided therein, A cold air outlet and a cold air inlet communicating with the cold air circulation duct are formed on the upper edge and lower edge of the front opening, respectively, and are generated through the cooler driven by the internal fan. The cool air thus blown is blown out from the cold air outlet toward the cold air inlet to form an air curtain, which cools the display chamber while shutting off external heat by the air curtain.

JP 2001-263904 A

In such an open showcase, although air curtains are formed, they are more susceptible to external heat than those equipped with doors. For example, some display rooms are exposed to sunlight and lighting. There is a possibility of partial temperature rise. Therefore, if the cooling capacity is increased to reduce the quality of the product displayed in such a temperature rising portion, or conversely to lower the temperature of the temperature rising portion, the other portions may be overcooled, The improvement was anxious.
The technology disclosed in this specification has been completed based on the above situation.

  The technology disclosed in the present specification includes a case main body having an opening on the front surface and having an inside as a display chamber, a cooler and an internal fan, and a cool air flow provided on a peripheral wall of the case main body. A cooling air outlet and a cooling air inlet provided in communication with the cooling air circulation duct at the upper edge and the lower edge of the opening, respectively, and the cooling by driving the internal fan In an open showcase in which an air curtain is formed by blowing cold air generated through a container from the cold air outlet toward the cold air inlet, a plurality of the internal fans are the width of the case main body. The same number of temperature sensors that are arranged at intervals in the direction and that individually detect the internal temperature at a plurality of locations set at intervals in the width direction in the display room, and detection of each temperature sensor A fan drive control device for individually controlling the rotational speed of each internal fan as the detected temperature based on time is substantially constant, a structure in which are provided.

According to the above configuration, the internal temperature is individually viewed for a plurality of regions divided in the width direction in the display room, and the region in which the internal temperature rises or falls due to the influence of external heat or displayed products is When it comes out, the internal fan placed in the same area is accelerated or decelerated, and the cold air in the area of the air curtain corresponding to the same area is increased or decreased, so that the internal temperature in the same area is increased. It is returned to the same as that of other areas.
In other words, when variations occur in the width direction of the cooling temperature (inside the chamber temperature) of the display room, the temperature is corrected quickly and the temperature distribution is made uniform, and the product does not deteriorate in quality throughout the display room. Can be displayed.

Here, the cold air circulation duct is formed across the bottom wall, the back wall and the ceiling wall of the case body, and a rear air outlet is provided on the back surface of the display chamber in communication with the cold air circulation duct. A part of the cold air flowing through the cold air circulation duct may be blown out from the rear outlet toward the display chamber.
When correcting the internal temperature, not only the air curtain but also the cold air blown out from the rear opening is increased or decreased, so that the internal temperature distribution can be made more uniform.

Another disclosed technique includes a case main body having an opening on the front surface and a display chamber inside, a cooler, and an internal fan, and extends across the bottom wall, the back wall, and the ceiling wall of the case main body. The formed cold air flow duct, the rear air outlet opened to the back of the display chamber in communication with the cold air flow duct, and the cold air flow duct communicated with the upper edge portion and the lower edge portion of the opening portion, respectively. A cool air outlet and a cold air inlet provided, and a part of the cool air generated by passing through the cooler by driving the internal fan is directed from the back outlet to the display chamber. In the open showcase in which the remaining part of the cold air is blown out from the cold air outlet toward the cold air inlet to form an air curtain, the display chamber has a plurality of display shelves. Arranged, said back The air outlet is divided into a plurality of positions corresponding to the respective display shelves, a temperature sensor for detecting the internal temperature is provided for each of the display shelves, and the detection of each temperature sensor A fan drive control device that controls the rotational speed of the internal fan based on the temperature is provided.
The internal temperature is monitored at each shelf level, and if there is a change in the internal temperature in the first shelf, the rotation speed of the internal fan is controlled according to the position of the shelf. As a result, the amount of cool air blown from the rear outlet to the display shelf is controlled, and the inside temperature of the display shelf is quickly corrected.

  Still another disclosed technique is a case main body having an opening on the front surface and the inside of which is a display chamber, a cooler and an internal fan, and a cold air circulation duct provided on a peripheral wall of the case main body. A cold air outlet and a cold air inlet provided in communication with the cold air circulation duct at the upper edge portion and the lower edge portion of the opening, respectively, are provided, and the cooling fan is driven with driving of the internal fan. Cold air generated through the cooler is blown out from the cold air outlet toward the cold air inlet to form an air curtain, and the cooler is heated while driving the internal fan. In the open showcase in which the defrosting operation for performing defrosting can be performed, the cooler and the internal fan are arranged side by side in front of and behind the flow direction of the cold air during the cooling operation, and the internal fan Is 2 Are arranged at intervals in the width direction of the case body, and during the defrosting operation, frost detection means for detecting the presence or absence of frost on the cooler, and the cooler by the frost detection means While it is detected that there is frost formation, the fans in both the cabinets are rotated in the same manner as in the cooling operation, and after it is detected that the cooler has no frost formation, A fan drive control device is provided in which the other internal fan is reversely driven while the internal fan is normally driven.

  According to the above configuration, when the so-called draining time after the frost melting is completed, the left and right internal fans are driven in the opposite direction so that a circulating flow passing through the cooler in the front-rear direction is generated. Done. During the draining time, the cooler becomes relatively hot and the circulation flow becomes warm, but the warm air only circulates before and after the cooler and does not flow to the display room side, so the display room is unnecessary. Temperature rise is avoided.

Here, the fan drive device has a function of reversing the rotation direction of the internal fans forward and backward each time a predetermined time elapses when the internal fans are rotationally driven in opposite directions. It is good also as composition which has.
The warm air circulating flow changes direction every predetermined time and passes through the cooler. Thereby, the draining operation of the cooler is promoted, and the draining time and thus the defrosting operation time can be shortened.

  According to the open showcase disclosed in the present specification, it is possible to quickly correct variations in the temperature distribution generated in the display room.

External perspective view of an open showcase according to Embodiment 1 Front view Longitudinal section showing its internal structure A perspective view with its bottom panel removed Block diagram showing control system for cooling operation Timing chart showing internal fan drive control The schematic plan view which shows the arrangement structure of the internal fan and temperature sensor which concern on Embodiment 2. FIG. Vertical sectional view of an open showcase according to Embodiment 3 Block diagram showing the control system of the internal fan The top view which shows the flow of the wind at the time of the internal structure of the cold air | flow distribution duct which concerns on Embodiment 4, and a defrost operation Block diagram showing the operation control system Timing chart showing internal fan drive control Timing chart showing drive control of internal fan according to embodiment 5 Plan view showing wind flow during defrosting operation The longitudinal cross-sectional view which shows the internal structure of the open showcase which concerns on Embodiment 6.

<Embodiment 1>
The first embodiment will be described with reference to FIGS. As shown in FIGS. 1 to 3, the open showcase of the present embodiment is configured by placing a case body 20 on the upper surface of a machine room 10.
The machine room 10 is formed in a horizontally long rectangular box shape, and is equipped with a refrigeration device 11 including a compressor 12, an air-cooled condenser 13 and the like, and support legs 15 on the bottom surface. Yes.
The case main body 20 is formed of a heat insulating box that has the same width (frontage) as the machine room 10 and has a depth larger than that of the machine room 10, and is generally a front opening. It is placed on the top surface.

In detail, the case body 20 has a front edge of the left and right side walls 21D as an inclined edge that gradually recedes back toward the upper end, while a front edge of the ceiling wall 21C is arranged in the back. Here, the front edge of the ceiling wall 21 </ b> C corresponds to the upper edge of the front opening 24, and the front edge of the bottom wall 21 </ b> A corresponds to the lower edge of the front opening 24.
A bottom panel 23A, a back panel 23B, and a ceiling panel 23C are stretched at intervals on the inner surfaces of the bottom wall 21A, the back wall 21B, and the ceiling wall 21C of the case body 20, and a cold air circulation duct 25 is formed therebetween. Yes. A display chamber 30 is formed by a space surrounded by the cold air distribution duct 25 and the left and right side walls 21D.
In the display chamber 30, display shelves 31 are provided across three levels. Each display shelf 31 is attached in a form protruding from the back panel 23B, and the protruding length is sequentially shortened from the lowermost display shelf 31.

A cooler 33 is installed on the bottom duct portion 26A of the cold air circulation duct 25 at a position slightly behind the center of the depth. The cooler 33 is formed in a horizontally long block shape, and as shown in FIG. 4, the cooler 33 is provided in a form in which both upper and lower surfaces are sandwiched in the most central region in the width direction of the bottom duct portion 26 </ b> A. The cooler 33 is circulated and connected by the refrigeration apparatus 11 in the machine room 10 and the refrigerant pipe 34 to constitute a known refrigeration circuit.
At the position in front of the cooler 33 in the bottom duct portion 26A, as shown in FIG. 4, three internal fans 35 for circulating cold air are arranged in a line at intervals in the width direction. Yes. For example, each internal fan 35 is arranged at a position corresponding to a central width position in each region obtained by dividing the display chamber 30 into three equal parts in the width direction.

A cold air outlet 27 is provided over substantially the entire width of the front edge portion of the ceiling duct portion 26 </ b> C in the cold air circulation duct 25, that is, the upper edge portion of the front opening 24. The cold air outlet 27 is formed of a honeycomb rectifier, and the direction in which the cold air is blown is directed to the front edge portion of the bottom duct portion 26A.
On the other hand, a cold air inlet 28 is formed over almost the entire width at the front edge of the bottom duct 26A, that is, the upper surface of the lower edge of the front opening 24. The cold air inlet 28 is formed by arranging a large number of slits.

  As shown in FIG. 2, the rear panel 23 </ b> B that forms the back surface of the display chamber 30 has a rear outlet 29 almost over the entire width at each position corresponding to the rear of the product display area in the three-stage display shelf 31. Is formed. Each rear outlet 29 is formed by aligning and opening a large number of slits, and communicates with the rear duct portion 26 </ b> B of the cold air circulation duct 25.

The cooling operation in the open showcase is performed by driving the refrigeration apparatus 11 and the internal fan 35, and the cold air generated by passing through the cooler 33 is cold as shown by the arrow in FIG. After flowing through the distribution duct 25, the air curtain AC is formed from the cold air outlet 27 toward the cold air inlet 28, and a part of the cold air is directed from each back outlet 29 toward the display chamber 30. The inside of the display chamber 30 is cooled while the external heat is shut off.
During this time, as will be described in detail later, the temperature of the display chamber 30 (internal temperature) is detected, and on / off control of the refrigeration apparatus 11 (compressor 12) is controlled based on a comparison between the detected temperature and a predetermined set temperature. As a result, the internal temperature is maintained substantially at the set temperature. On the other hand, since it is necessary to form the air curtain AC, the internal temperature is controlled regardless of whether the refrigeration apparatus 11 (compressor 12) is on or off. The inner fan 35 is continuously driven.

Now, in this embodiment, when cooling the display chamber 30, the distribution of the internal temperature in the width direction of the display chamber 30 is made uniform so that the cooling temperature (internal temperature) in the display chamber 30 does not vary. Measures are taken to do this.
Each of the three internal fans 35 is a variable speed type in which the rotation speed can be switched in three stages (high speed, standard, low speed).
On the other hand, as shown in FIG. 3, temperature sensors 37 are individually provided in the bottom duct portion 26 </ b> A of the cold air circulation duct 25 at positions immediately after the three internal fans 35.
Hereinafter, when distinguishing the three internal fans 35, as shown in FIG. 4, the first internal fan 35A, the second internal fan 35B, and the third internal fan are sequentially arranged from the left side when viewed from the front. This will be described as 35C.
Similarly, when distinguishing the three temperature sensors 37, it demonstrates as the 1st temperature sensor 37A, the 2nd temperature sensor 37B, and the 3rd temperature sensor 37C sequentially from the left side by front view.

  Each of the three temperature sensors 37 functions to individually detect the temperature of the cold air in the region divided into three in the width direction of the air curtain AC. Here, with the temperature of each cold air in the three regions of the air curtain AC, the internal temperature of the region (left region, central region, and right region) divided in the width direction in the display chamber 30 is simulated. As a result, each temperature sensor 37 individually detects the internal temperature of the three areas of the display chamber 30.

In the present embodiment, by individually controlling the rotation speed of each internal fan 35 during the cooling operation, the internal temperature distribution in the width direction of the display chamber 30 is made uniform. A control system as shown in FIG. 5 is formed for the cooling operation including the drive control.
The control system includes a cooling operation control unit 40 that includes a microcomputer and can execute a predetermined program. The cooling operation control unit 40 includes a compressor drive control unit 41 and a fan drive control unit 45.

The first to third temperature sensors 37A, 37B, and 37C are connected to the input side of the cooling operation control unit 40, and the compressor 12 constituting the refrigeration apparatus 11 and the first to third temperature sensors 37A, 37B, and 37C are connected to the output side. Third internal fans 35A, 35B, and 35C are connected.
The compressor drive control unit 41 functions to control on / off of the compressor 12, and includes a first temperature storage unit 42 and a first comparison unit 43. The first comparison unit 43 compares the detected temperatures from the first to third temperature sensors 37A, 37B, and 37C with the set temperature of the internal temperature called from the first temperature storage unit 42, and more details As shown in FIG. 6, the compressor 12 is turned off when all the detected temperatures of the temperature sensors 37 are lowered to the lower limit value of the set temperature, and even one of the detected temperatures of the temperature sensors 37 is set. When the temperature reaches the upper limit value, the compressor 12 is turned on.

  The fan drive control unit 45 functions to individually control the rotational speeds of the three internal fans 35 and includes a second temperature storage unit 46 and a second comparison unit 47. As shown in FIG. 6, the second temperature storage unit 46 includes a set temperature of the above-described internal temperature, a rotation acceleration temperature Tu that is higher than the set temperature by a predetermined temperature, and a rotation suppression temperature Td that is lower than the predetermined temperature. Is stored. The set temperature of the internal temperature, the rotation acceleration temperature Tu, and the rotation suppression temperature Td are collectively referred to as a reference temperature.

  The second comparison unit 47 individually compares the detected temperatures of the first to third temperature sensors 37A, 37B, and 37C with the reference temperature called from the second temperature storage unit 46, and responds based on the comparison result. It functions to output drive signals to the internal fans 35A, 35B, and 35C. Specifically, if the detected temperature of one temperature sensor 37 is equal to or higher than the rotation acceleration temperature Tu, the corresponding internal fan 35 is driven at a high speed, and when the detected temperature reaches the set temperature (lower limit value / upper limit value) The internal fan 35 is driven as a standard, and when the detected temperature falls below the rotation suppression temperature Td, the internal fan 35 is driven at a low speed.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG. In FIG. 6, the chart for the third internal fan 35 </ b> C is omitted in order to simplify the description.
The cooling operation is started by driving the compressor 12 and the three in-compartment fans 35, and at the same time, the in-compartment temperatures of the three regions of the display chamber 30 are detected by each temperature sensor 37. Initially, since the temperature detected by the total temperature sensor 37 is equal to or higher than the rotation acceleration temperature Tu, the internal fan 35 is driven at high speed. As a result, the air curtain AC is formed with a high flow rate and cool air, and the cool air is blown into the display chamber 30, whereby the inside of the display chamber 30 is rapidly cooled.

During this time, the internal temperature of each area in the display chamber 30 is observed by each temperature sensor 37. When the detected temperature reaches the lower limit value of the set temperature, the corresponding internal fan 35 is lowered to the standard drive, When the thermal load is different for each region, the temperature detected by each temperature sensor 37 reaches the lower limit value of the set temperature while causing a time lag, and the internal fans 35 are sequentially lowered to the standard drive. Become. When all the detected temperatures reach the lower limit value of the set temperature, the compressor 12 is turned off. On the other hand, the standard drive of all the fans 35 is continued.
After a lapse of time, when the detected temperature in one region rises to the upper limit value of the set temperature, the compressor 12 is turned on, and thereafter, the compressor 12 is repeatedly turned on and off while the standard drive of the internal fan 35 is continued. Thus, the inside of the display room 30 is maintained near the set temperature.

  During the cooling operation, the display room 30 may partially rise in temperature when sunlight or lighting is applied to a part of the display room 30 or when a warm product is put. As a result, the internal temperature of one area of the display chamber 30 rises, and when the detected temperature of one area rises to the rotation acceleration temperature Tu as shown at timings t1 and t2 in the timing chart of FIG. The inner fan 35 is switched from the standard drive to the high speed drive. As a result, the amount of cool air is increased in the area of the air curtain AC corresponding to the same area of the display chamber 30, and the amount of cool air flowing in from the rear outlet 29 is also increased, thereby rapidly cooling the area. When the detected temperature in the same area reaches the lower limit value of the set temperature, the corresponding internal fan 35 is returned to the standard drive.

  On the other hand, when the internal temperature of the display chamber 30 is lowered for some reason and the detected temperature decreases to the rotation suppression temperature Td as at timing t3, the corresponding internal fan 35 is changed from the standard drive to the low speed drive. Can be switched. As a result, the amount of cool air is reduced in the area of the air curtain AC corresponding to the same area of the display chamber 30, and the amount of cool air flowing in from the rear outlet 29 is also reduced, so that the temperature of the area increases. When the detected temperature in the same region reaches the upper limit value of the set temperature, the corresponding internal fan 35 is returned to the standard drive.

As described above, according to the present embodiment, the internal temperature is individually observed for the three regions divided in the width direction in the display chamber 30, and the internal temperature is affected by the external heat and the displayed products. When an area that exceeds or falls below the set temperature appears, the internal fan 35 disposed corresponding to the area is accelerated or decelerated, and air in the area of the air curtain AC corresponding to the area is cooled. The cold air blown out from the back surface to the same area is increased or decreased, so that the internal temperature of the same area is returned to the vicinity of the set temperature.
In short, when the cooling temperature (internal temperature) of the display chamber 30 varies in the width direction, it is quickly corrected and the temperature distribution is made uniform. As a result, the quality of the entire display chamber 30 is improved. Products can be displayed without causing deterioration.

  In addition, about the dispersion | variation in the inside temperature in the display room 30, since it is thought that there are many cases where temperature rises partially, and the time of temperature rise has a large influence on the quality of goods, this situation When stagnated, the standard and high-speed two-stage switching type is applied to the internal fan 35, and the internal fan 35 is always driven as a standard, and if there is a partial temperature rise, the corresponding internal fan You may make it take the control aspect of driving the fan 35 at high speed.

<Embodiment 2>
A second embodiment will be described with reference to FIG. In the first embodiment, the number of the internal fans 35 and the temperature sensors 37 are three, but the numbers are not necessarily the same.
For example, as shown in FIG. 7, three internal fans 35 are arranged in the same manner as in the first embodiment, whereas two temperature sensors 37 are arranged at a position between adjacent internal fans 35. The

  As an example of fan control, the difference between the detected temperatures of the two temperature sensors 37 is observed, and the rotation speed of each internal fan 35 is switched depending on the magnitude of the temperature difference. Specifically, if the temperature difference between the detected temperature of the left temperature sensor 37 and the detected temperature of the right temperature sensor 37 is equal to or greater than a set value, the left and center internal fans 35 are switched to high speed driving, and the same When the temperature difference falls below the set value, the drive control of the internal fan 35 is performed such that only the left internal fan 35 is kept at high speed drive, so that the inside of the display room 30 can be quickly and without over-cooling. The temperature difference can be eliminated.

<Embodiment 3>
Embodiment 3 will be described with reference to FIGS. In the third embodiment, it is intended to eliminate the variation in the cooling temperature (internal temperature) for each display shelf 31 of each stage. Hereinafter, differences from the first embodiment will be mainly described, and portions and members having the same functions as those of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted or simplified.
In this embodiment, as shown in FIG. 8, a temperature sensor 37 that directly detects the internal temperature is provided for each of the three-stage display shelves 31 (31X, 31Y, 31Z) arranged in the display room 30. Yes. Specifically, the display shelf 31 is mounted at the center width position at the upper front edge. Hereinafter, when the three temperature sensors 37 are distinguished from each other, they will be described as an upper temperature sensor 37X, an intermediate temperature sensor 37Y, and a lower temperature sensor 37Z sequentially from the top.
Similarly, the internal fan 35 is a variable speed type of three stages (high speed, standard, low speed). The number of the internal fans 35 may be one or a plurality of two or more. However, in the case of a plurality, the rotational speeds of the internal fans 35 can be switched together. .

In order to perform drive control of the internal fan 35, a fan drive control unit 50 is provided as shown in FIG. 9, and on the output side, the upper and lower display shelves 31X, 31Y, 31Z are mounted. Middle temperature sensors 37X, 37Y, and 37Z are connected, and an internal fan 35 is connected to the output side.
The fan drive control unit 50 includes a temperature storage unit 51 and a comparison unit 52. The temperature storage unit 51 stores a set temperature of the internal temperature and a cooling acceleration temperature that is higher than the set temperature by a predetermined temperature. The set temperature and the cooling acceleration temperature are collectively referred to as a reference temperature.

The comparison unit 52 individually compares the detected temperatures of the upper, middle, and lower temperature sensors 37X, 37Y, and 37Z with the reference temperature called from the temperature storage unit 51, and the internal fan 35 is based on the comparison result. It functions to issue a drive signal.
Specifically, when the temperature detected by the lower temperature sensor 37Z rises above the cooling acceleration temperature, the internal fan 35 is switched from the standard drive to the low speed drive. On the other hand, when the temperature detected by the upper temperature sensor 37X or the intermediate temperature sensor 37Y rises to the cooling acceleration temperature or higher, the internal fan 35 is switched from the standard drive to the high speed drive.

  The operation of this embodiment is as follows. During normal cooling operation, the internal fan 35 is driven as standard, and the compressor 12 is turned off when the temperature detected by the three temperature sensors 37 drops to the lower limit of the set temperature. When the temperature detected by the temperature sensor 37 rises to the upper limit value of the set temperature, the compressor 12 is repeatedly turned on, so that the inside temperature of the display chamber 30 is maintained substantially at the set temperature.

  Here, for example, when a product having a relatively high temperature and a volume is put in the lower display shelf 31Z, it is difficult to cool them, so that the interior temperatures of the other display shelves 31X and 31Y become the set temperature. Despite being lowered, the internal temperature of the lower display shelf 31Z does not readily fall to the set temperature. Since the compressor 12 is turned off only when the detection temperatures of all the three-stage temperature sensors 37 are all lowered to the set temperature as described above, the internal temperature of the lower display shelf 31Z is lowered to the set temperature. The compressor 12 is kept on. As a result, the running cost is high, and the products displayed on the other upper and middle display shelves 31X and 31Y tend to be cooled too much.

  As the above countermeasure, when the temperature detected by the lower temperature sensor 37Z of the lower display shelf 31Z rises to the cooling acceleration temperature, the internal fan 35 is switched from the standard drive to the low speed drive. As a result, the amount of cold air flowing in the cold air circulation duct 25 decreases, the cold air does not rise above the duct 25, and the cold air is blown out mainly from the lower rear outlet 29Z, and the products on the lower display shelf 31Z Cooling early, the internal temperature also falls to the set temperature early, and as a result, the compressor 12 is also turned off early. Therefore, the on-time of the compressor 12 can be shortened, which can contribute to the reduction of running cost. In addition, overcooling of the products on the other upper and middle display shelves 31X and 31Y can be avoided.

  On the other hand, when the heat load on the upper or lower display shelves 31X and 31Y increases and the temperature detected by the upper temperature sensor 37X or the intermediate temperature sensor 37Y rises to the cooling acceleration temperature, the internal fan 35 switches from the standard drive to the high speed drive. It is done. As a result, the amount of cold air flowing in the cold air circulation duct 25 is increased, and the amount of cold air blown from the corresponding upper rear outlet 29X or middle rear outlet 29Y is also increased, thereby cooling early. Alternatively, the inside temperature of the middle stage is lowered to the set temperature at an early stage. As a result, the compressor 12 is turned off early, and the running cost is reduced. In this case, there is a concern that the amount of cool air blown out from the rear air outlet 29 for all stages will cause the heat load to be overcooled with respect to normal products. Since it is off, excessive cooling is minimized.

  A mechanism for automatically opening and closing each rear outlet 29 is provided, and as described above, when the interior temperature of the upper or middle display shelf 31 is lowered to the set temperature at an early stage, the rear outlets 29 of other stages are opened. If the degree is decreased, the amount of cool air blown out to the corresponding display shelf 31 can be further increased, and the cooling rate can be increased. On the other hand, it is possible to reliably prevent the other display shelves 31 from being overcooled.

<Embodiment 4>
A fourth embodiment will be described with reference to FIGS. In the fourth embodiment, it is intended to prevent the temperature in the display chamber 30 from unnecessarily rising during the defrosting operation.
The structure of the open showcase of the present embodiment has been slightly modified based on the structure illustrated in the first embodiment, and will be described below.
Specifically, the number and arrangement structure of the internal fans 35 and temperature sensors 37 are changed. As shown in FIG. 10, a pair of left and right internal fans 35 (a left internal fan 35L and a right internal fan 35R) are arranged in the width direction at a position in front of the cooler 33 in the bottom duct portion 26A of the cold air circulation duct 25. Are arranged side by side at intervals. For example, the internal fans 35L and 35R are respectively disposed at positions corresponding to the central width positions in the respective regions obtained by dividing the display chamber 30 into two equal parts in the width direction.
On the other hand, a single temperature sensor 37 is provided behind the internal fans 35L and 35R and is positioned between the internal fans 35L and 35R.

The cooling operation will be described with reference to the block diagram of FIG. 11 and the timing chart of FIG.
The cooling operation is executed by a cooling operation control unit 61 provided in the operation control unit 60 shown in FIG. The cooling operation is performed when the compressor 12 is turned on and the left and right internal fans 35L and 35R are driven to rotate forward and pass through the cooler 33 as indicated by the arrow in FIG. After the cool air generated in this way flows through the cool air circulation duct 25, the cool air is blown out from the cool air outlet 27 toward the cold air inlet 28 to form an air curtain AC, and a part of the cool air is supplied to each rear outlet. 29 is blown out toward the display room 30, thereby cooling the inside of the display room 30 while blocking external heat.
During this time, the internal temperature of the display chamber 30 is detected by the temperature sensor 37, and based on a comparison between the detected temperature and a predetermined set temperature, that is, when the detected temperature rises to the upper limit value of the set temperature, the compressor 12 When the detected temperature falls to the lower limit value of the set temperature, the compressor 12 is turned off. By repeating the operation, the display chamber 30 is maintained substantially at the set temperature, while the air curtain AC Since the formation is necessary, both the internal fans 35L and 35R are continuously driven to rotate forward regardless of whether the compressor 12 is on or off.

In the present embodiment, the defrosting operation can be executed automatically or manually during the above cooling operation, and in particular, the drive control of the internal fan 35 during the defrosting operation is devised. This will be described below.
The operation control unit 60 is provided with a defrosting operation control unit 62. On the input side, a defrosting switch 65 that is turned on automatically by a 24-hour timer or the like or by manual operation is connected and output. A heater 66 provided in the cooler 33 is connected to the side. When the defrost switch 65 is turned on, the compressor 12 is turned off and the heater 66 is energized, and the fans 35 in both the compartments are basically continuously driven.

The defrosting operation control unit 62 includes a fan drive control unit 62A that controls driving of the internal fan 35. The fan drive control unit 62A is provided with a frost detection unit 63 and a timer 64. ing. As shown in FIGS. 10 and 11, the cooler 33 is equipped with a defrost detection temperature sensor 38 (defrost temperature sensor 38) for detecting the temperature of the cooler 33, and is connected to the input side. Yes. In addition, the location where the defrost temperature sensor 38 is mounted is preferably a location where frost is most likely to remain.
And if the detection temperature rises to predetermined defrost temperature based on the detection temperature of the defrost temperature sensor 38 after defrost operation start, the frost detection part 63 will consider that there is no frost in the cooler 33. A defrosting completion signal is output. When the defrosting completion signal is output, energization to the heater 66 is stopped. At the same time, it functions to switch the right internal fan 35R from forward rotation to reverse rotation. The left warehouse fan 35L continues to be driven forward.
The timer 64 starts timing when a defrosting completion signal is issued, and when a predetermined time (water draining time) is timed (time up), a defrosting operation end signal is output. Yes. When the defrosting operation end signal is output, the compressor 12 is turned on and the cooling operation control described above is resumed after the right internal fan 35R is returned from the reverse rotation driving to the normal rotation driving. ing.

The operation of the fourth embodiment will be described again with reference to the timing chart of FIG.
As described above, the cooling operation is performed by turning on and off the compressor 12 after the left and right internal fans 35L and 35R are continuously driven to rotate forward, thereby forming the air curtain AC. The inside of the display chamber 30 is cooled to almost the set temperature with the circulation of iso-cooled air.
When the defrost switch 65 is turned on during the cooling operation (timing ta), the defrost operation is started. Specifically, the compressor 12 is turned off and the heater 66 is energized to heat the cooler 33 and the frost attached thereto is gradually melted. During this time, the internal fans 35L and 35R are driven forward. Is continued, frost melting is promoted.

  After the frost has been melted, the wind is continuously applied to drop the water droplets remaining in the cooler 33. Although the wind drawn by the internal fan 35 is applied to the cooler 33, since the frost itself becomes a cooling source while the frost remains in the cooler 33, the display chamber 30 side has a low temperature. While the wind is circulated and circulating, the temperature of the circulating flow rises when the frost disappears from the cooler 33, so that the internal temperature of the display chamber 30 rises unnecessarily.

Therefore, in the present embodiment, during the defrosting operation, when the detection temperature of the defrosting temperature sensor 38 rises to a predetermined defrosting temperature (timing tb), it is considered that the cooler 33 has no frosting and the defrosting completion signal is output. As a result, the energization of the heater 66 is stopped. At the same time, the forward rotation drive of the left internal fan 35L is continued, while the right internal fan 35R is switched from the forward drive to the reverse drive.
Although the heat generation of the heater 66 is stopped, the remaining heat tends to increase the temperature of the cooler 33, but the left and right internal fans 35L and 35R are rotationally driven in opposite directions. In addition, as shown by the arrow in FIG. 10, the warm air circulation flow in the clockwise direction in a plan view in which the wind toward the far side of the left side of the cooler 33 returns to the front side of the right side of the cooler 33. This effectively functions to drop the water droplets remaining in the cooler 33, while the warm air only circulates before and after the cooler 33 and does not flow to the display chamber 30 side. Necessary temperature increases can be avoided.

  When a predetermined dewatering time has elapsed (timing tc) after the defrosting completion signal is output and the left and right internal fans 35L and 35R are driven in opposite directions, a defrosting operation end signal is output. As a result, the compressor 12 is turned on, the right internal fan 35R is returned from the reverse rotation drive to the normal rotation drive, and the left and right internal fans 35L and 35R are aligned to be in the normal rotation drive state. Thus, the cooling operation control described above is resumed.

  According to the present embodiment, when the drainage time after the completion of frost melting is entered, the left and right internal fans 35L and 35R are rotationally driven in opposite directions so that the circulating flow passes through the cooler 33 in the front-rear direction. Occurs and draining is performed. In the draining time, the cooler 33 becomes relatively hot and the circulation flow becomes warm air. However, the warm air is circulated before and after the cooler 33 and does not circulate to the display chamber 30 side. It is avoided that the temperature rises unnecessarily.

<Embodiment 5>
A fifth embodiment will be described with reference to FIGS. The fifth embodiment is obtained by further improving the fourth embodiment.
Briefly, during the defrosting operation, after the temperature detected by the temperature sensor 37 rises to a predetermined defrosting temperature and a defrosting completion signal is issued, the left and right internal fans 35L and 35R rotate in opposite directions. When driven, as shown in the timing chart of FIG. 13, the rotation direction of the internal fans 35L, 35R is reversed every predetermined time. As a result, as shown in FIG. 14, the warm air flow W1 in the clockwise direction in the plan view and the warm air flow W2 in the counterclockwise direction alternately flow through the cooler 33 every predetermined time.
Thereby, the draining operation from the cooler 33 is promoted, and the draining time and thus the defrosting operation time can be shortened.

<Embodiment 6>
FIG. 15 shows a sixth embodiment. When a plurality of internal fans 35 are arranged in the cold air circulation duct 25 at intervals in the width direction, as shown in FIG. 15, the bottom duct portion 26A and the rear duct portion 26B are included in the cold air duct 25. You may make it arrange | position the fan 35 in a store in the diagonal position to the corner | angular part which crossed.
The distribution of the cold air in the cold air distribution duct 25 can be performed more smoothly.

<Other embodiments>
The technology disclosed in this specification is not limited to the embodiments described with reference to the above description and drawings, and includes the following embodiments, for example.
(1) In the first embodiment, it may be of a type in which only an air curtain is formed without providing a rear opening.
(2) In Embodiment 3, the mounting position of the temperature sensor is not limited to the illustrated position, or is hung from the lower side of the front edge of the display shelf, from the display shelf or the ceiling panel above each display shelf, or If it is a small one that does not interfere with the display of merchandise, it can be mounted at other appropriate positions such as the center of the upper surface of the display shelf.
(3) In the fourth and fifth embodiments, a pair of internal fan fans including left and right internal fan fans are arranged side by side in the set width direction, and the cooler is moved in the front-rear direction during the draining time. A circulating circulation of warm air that passes through the two may be formed side by side in a plurality of flow width directions.
(4) In the fourth and fifth embodiments, the case where the heater is used during the defrosting operation is illustrated. However, the heater may be used and the defrosting may be performed only by applying the wind after stopping the compressor. The drive control of the internal fan is the same.

  DESCRIPTION OF SYMBOLS 20 ... Case main body 21A ... Bottom wall 21B ... Back wall 21C ... Ceiling wall 24 ... Front opening 25 ... Cold air distribution duct 27 ... Cold air outlet 28 ... Cold air inlet 29, 29X, 29Y, 29Z ... Back outlet 30 ... Display Chamber 31, 31X, 31Y, 31Z ... Display shelf 33 ... Cooler 35, 35A, 35B, 35C, 35L, 35R ... Inside fan 37, 37A, 37B, 37C, 37X, 37Y, 37Z ... Temperature sensor 40 ... Fan drive Control unit 46 ... second temperature storage unit 47 ... second comparison unit 50 ... fan drive control unit 51 ... temperature storage unit 52 ... comparison unit 60 ... operation control unit 62 ... defrost operation control unit 62A ... fan drive control unit 63 ... Frosting detection part 64 ... Timer 65 ... Defrost switch 66 ... Heater AC ... Air curtain

Claims (5)

A case body having an opening on the front surface and the inside of which is a display room;
A cool air circulation duct provided on the peripheral wall of the case body with a cooler and an internal fan provided therein;
A cold air outlet and a cold air inlet provided in communication with the cold air circulation duct at the upper edge and the lower edge of the opening, respectively,
In the open showcase in which the air curtain is formed by blowing the cold air generated by passing through the cooler by driving the internal fan from the cold air outlet toward the cold air inlet,
A plurality of the internal fans are arranged at intervals in the width direction of the case body,
The same number of temperature sensors that individually detect the internal temperature of a plurality of locations set at intervals in the width direction in the display room;
And a fan drive control device for individually controlling the rotational speed of each internal fan so that each detected temperature becomes substantially constant based on the detected temperature of each temperature sensor. Case. The cold air circulation duct is formed across the bottom wall, the back wall and the ceiling wall of the case body, and a rear air outlet is provided on the back surface of the display chamber so as to communicate with the cold air circulation duct. 2. The open showcase according to claim 1, wherein a part of the cold air flowing through the flow duct is blown out toward the display room from the back outlet. A case body having an opening on the front surface and the inside of which is a display room;
A cooler and an internal fan, a cold air flow duct formed across the bottom wall, back wall and ceiling wall of the case body;
A rear outlet that is in communication with the cold air distribution duct and is opened at the back of the display chamber;
A cold air outlet and a cold air inlet provided in communication with the cold air circulation duct at the upper edge and the lower edge of the opening, respectively,
A part of the cold air generated by passing through the cooler by driving the internal fan is blown out from the back outlet toward the display chamber,
In the open showcase in which the remaining part of the cold air is blown out from the cold air outlet toward the cold air inlet to form an air curtain,
In the display room, display shelves are arranged in a plurality of stages,
The rear outlet is divided into a plurality of positions corresponding to the respective display shelves, and
A temperature sensor for detecting the internal temperature is provided for each display shelf,
And the open showcase characterized by the fan drive control apparatus which controls the rotational speed of the said internal fan based on the detected temperature of each said temperature sensor being provided. A case body having an opening on the front surface and the inside of which is a display room;
A cool air circulation duct provided on the peripheral wall of the case body with a cooler and an internal fan provided therein;
A cold air outlet and a cold air inlet provided in communication with the cold air circulation duct at the upper edge and the lower edge of the opening, respectively,
During the cooling operation, the cool air generated by passing through the cooler with the driving of the internal fan is blown out from the cold air outlet toward the cold air inlet to form an air curtain,
In the open showcase in which the defrosting operation for heating and defrosting the cooler with the driving of the internal fan can be performed,
The cooler and the internal fan are arranged side by side in the cooling air flow direction during the cooling operation, and two internal fans are arranged at intervals in the width direction of the case body. And
Frost detection means for detecting the presence or absence of frost on the cooler during the defrosting operation;
While it is detected by the frost detection means that the chiller is frosted, the fans in both the cabinets are rotated in the same manner as in the cooling operation, and the chiller has no frost. After this is detected, an open showcase is provided, wherein a fan drive control device is provided to drive one of the internal fans in the normal direction while rotating the other internal fan in the reverse direction. The fan driving device has a function of reversing the rotation direction of the internal fans forward and backward every time a predetermined time elapses when the internal fans are rotationally driven in opposite directions. The open showcase according to claim 4, wherein:

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