JP2009138967A - Open showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an open showcase capable of significantly improving controllability in controlling a showcase temperature. <P>SOLUTION: This open showcase comprises a main cold air trunk 52 forming an air curtain 50 at an opening portion 4, a return cold air trunk 60 having a return fan 92 sucking a part of the cold air forming the air curtain, a warm air trunk 70 having a warm air fan 90 sucking a part of the cold air forming the air curtain, and heating the same by a heater unit 88 to produce warm air, and a control unit 10 for keeping the showcase temperature T<SB>2</SB>roughly constant by starting or stopping the return fan, the warm air fan and the heater unit on the basis of temperatures T<SB>1</SB>, T<SB>2</SB>, T<SB>3</SB>detected by a cold air temperature detecting means 80, a showcase temperature detecting means 82 and a warm air temperature detecting means 84. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an open showcase, and more particularly to an open showcase suitable for managing a plurality of storage rooms at different temperatures.

  Conventionally, this type of open showcase is installed in a store such as a convenience store, and the interior of the showcase body having an opening on the front is a lower storage room that is hotter than the upper storage room and the upper storage room by a partition shelf A two-temperature type that is divided into two is known. The showcase body is formed with cold air passages along the top, bottom and back surfaces of the showcase body. An air curtain is formed in the opening by sucking from a suction port formed on the side.

And as such a two-temperature type open showcase, a fan equipped with a fan for controlling the amount of cold air blown into each of the storage rooms according to the temperature of the upper storage room and the lower storage room ( For example, Patent Document 1), and a heater that is provided in a lower chamber to control the temperature of the lower chamber (for example, see Patent Document 2) are known. According to each of these prior arts, for example, the upper storage room is managed at about 15 ° C. for side dish display, and the lower storage room is managed at about 20 ° C. higher than the upper storage room for cooked rice display. In addition, products such as side dishes and cooked rice can be displayed at an appropriate temperature according to the type.
Japanese Patent Laid-Open No. 11-23133 JP-A-8-254384

  However, in each of the above prior arts, since the fan speed and the heater temperature are adjusted only in accordance with the temperature of the room to be controlled, there remains a problem with improving the control response of the room temperature control. Yes. Specifically, it may be difficult to maintain the storage room temperature properly depending on a sudden change in store temperature or an increase or decrease in the number of products displayed in the storage room. If the temperature of the storage room decreases, the water content of the cooked rice in the lunch box may evaporate and dry, leading to a reduction in product quality.

  This invention is made | formed in view of such a subject, and it aims at providing the open showcase which can improve the controllability of storage room temperature control significantly.

  In order to achieve the above object, an open showcase according to claim 1 includes a showcase body having an opening on a front surface, a partition shelf for partitioning the interior of the showcase body into compartments of different temperatures, and a showcase A main cold air passage formed along the upper surface, the back surface and the bottom surface of the main body, a fan disposed in the bottom surface side cold air passage, and a cooler disposed in the back surface side cold air passage, Air is cooled by a cooler via a fan, and after the cold air is blown out from the air outlet formed at the front end of the upper surface side cold air passage, the air is sucked from the suction port formed at the front end of the bottom surface side cold air passage Is an open showcase that forms an air curtain in the opening, and has a return fan that sucks a part of the cold air that forms the air curtain, and the sucked cold air is stored in a predetermined warehouse of the warehouses. A return cool air passage that bypasses the surface and returns to the cooler, and a hot air fan that sucks a part of the cool air forming the air curtain and heats it with the heater unit to form the hot air, From the hot air passage that is blown out from the hot air outlet formed on the back of the chamber, the chamber temperature detecting means that detects the temperature of the predetermined chamber, the cold air temperature detecting means that detects the temperature of the cold air, and the hot air outlet The hot air temperature detecting means for detecting the temperature of the hot air before being blown, and the return fan, the hot air fan and the heater unit are started or stopped according to the temperature detected by each temperature detecting means, and the storage room And a control unit that holds the chamber temperature detected by the temperature detecting means at a predetermined set temperature substantially constant.

  According to a second aspect of the present invention, in the first aspect, the control unit is set so that the cold air temperature detected by the cold air temperature detecting means is set from the set temperature so as to ensure a predetermined allowable range of the set temperature. It is determined whether or not the temperature is less than the allowable temperature minus the temperature difference. If the cold air temperature is lower than the allowable temperature, the environment temperature where the open showcase is installed is determined as the low temperature mode, and the cold air temperature is set. When the temperature is equal to or higher than the temperature, the environmental temperature is determined as the high temperature mode, and when the cold air temperature is higher than the allowable temperature and lower than the set temperature, the environmental temperature is determined as the medium temperature mode.

Further, in the invention according to claim 3, in claim 2, when it is determined that the environmental temperature is in the low temperature mode, the control unit activates the return fan and the hot air fan, and the heater according to the room temperature. It is characterized by starting or stopping the unit.
Furthermore, in the invention described in claim 4, in the second or third aspect, the control unit starts or stops the heater unit according to the hot air temperature when it is determined that the environmental temperature is in the low temperature mode. It is a feature.

Further, in the invention according to claim 5, in any one of claims 2 to 4, when it is determined that the environmental temperature is in the high temperature mode, the control unit activates the return fan and the hot air fan and turns on the heater unit. It is characterized by stopping.
Furthermore, in the invention described in claim 6, in any one of claims 2 to 5, the control unit stops the return fan, the heater unit, and the heater unit when it is determined that the environmental temperature is in the intermediate temperature mode. It is a feature.

  Furthermore, in the invention described in claim 7, in any one of claims 2 to 6, there is provided environmental temperature detecting means for detecting the environmental temperature, and the control unit is adapted to the environmental temperature detected by the environmental temperature detecting means. It is characterized by switching between a low temperature mode, a medium temperature mode, and a high temperature mode.

  According to the open showcase of the present invention as set forth in claim 1, each temperature detecting means for detecting the temperature of the storage room, the cold air and the hot air, respectively, and the return fan according to the temperature detected by each temperature detecting means And a control unit that starts or stops the hot air fan and the heater unit and maintains the chamber temperature detected by the chamber temperature detecting means at a predetermined set temperature substantially constant. As a result, not only the room temperature, but also the cold room temperature affected by the temperature in the store in the air curtain and the hot room temperature before being blown out from the hot air outlet can be controlled in advance to perform the room temperature control. As a result, the responsiveness of the storage room temperature control can be improved and the controllability can be greatly improved. As a result, the storage room temperature can be properly maintained regardless of the temperature in the store. It is possible to properly manage the quality of products displayed on the market.

  According to the second aspect of the present invention, the control unit is configured to set a temperature difference that is set so that the cold air temperature detected by the cold air temperature detecting means is within a predetermined allowable range of the set temperature from the set temperature. It is determined whether or not the temperature is less than the allowable temperature, and if the cold air temperature is lower than the allowable temperature, the environmental temperature where the open showcase is installed is determined as the low temperature mode, and the cold air temperature is higher than the set temperature. In some cases, the environmental temperature is determined as the high temperature mode, and when the cold air temperature is higher than the allowable temperature and lower than the set temperature, the environmental temperature is determined as the medium temperature mode. As a result, the ambient temperature in which the open showcase is installed is classified according to the cold air temperature, and the optimum chamber temperature control can be performed in each mode, further improving the controllability of the chamber temperature control. Can be improved.

  In particular, as a criterion for mode switching, not only the set temperature of the cold air temperature but also the allowable temperature obtained by subtracting the temperature difference set to ensure a predetermined allowable range of the set temperature from the set temperature, The mode switching can be smoothly performed by suppressing the hunting phenomenon of the mode switching accompanying the fluctuation of the temperature, and the controllability of the chamber temperature control can be further improved.

  Further, according to the third aspect of the present invention, the control unit activates the return fan and the hot air fan when the environmental temperature is determined to be in the low temperature mode, and activates the heater unit according to the chamber temperature. Or stop. As a result, it is possible to rapidly warm the interior of the storage room with warm air and quickly prevent a decrease in the storage room temperature due to a decrease in the environmental temperature, and it is possible to selectively use hot air and cold air according to the temperature of the storage room. For this reason, it is possible to maintain the interior of the storage room at an appropriate temperature in a state where the control response is enhanced, and it is possible to further improve the controllability of the storage room temperature control.

  Furthermore, according to the invention of claim 4, when it is determined that the environmental temperature is in the low temperature mode, the control unit starts or stops the heater unit according to the hot air temperature. Thereby, since warm air and cold air can be properly used according to the warm air temperature of the warm air before being blown into the warehouse, the interior of the warehouse is kept at an appropriate temperature with further improved control responsiveness. Therefore, the controllability of the chamber temperature control can be further improved.

  According to the invention described in claim 5, when it is determined that the environmental temperature is in the high temperature mode, the control unit starts the return fan and the hot air fan and stops the heater unit. As a result, it is possible to quickly cool the interior of the warehouse with cold air and quickly prevent an increase in the temperature of the warehouse due to an increase in the environmental temperature. It can hold | maintain and the controllability of storage room temperature control can further be improved.

  According to the sixth aspect of the present invention, the control unit stops the return fan, the heater unit, and the heater unit when it is determined that the environmental temperature is in the intermediate temperature mode. As a result, when in the intermediate temperature mode in which the chamber temperature is optimum only by forming the air curtain, the cool air in the return cold air passage and the warm air in the hot air passage are not formed, and the cold air temperature and the amount of cold air are not formed on the front surface of the compartment. Since the air curtain that is substantially constant is formed and the chamber temperature can be maintained substantially constant, the controllability of the chamber temperature control can be further improved.

  Furthermore, according to the invention described in claim 7, the control unit switches the low-temperature mode, the medium-temperature mode, and the high-temperature mode according to the environmental temperature detected by the environmental temperature detecting means. Since the mode can be switched in consideration of the actual environmental temperature variation that is the main cause of the variation, the controllability of the chamber temperature control can be further improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a side sectional view of an open showcase 2 of the present embodiment. The showcase 2 is installed in a store such as a convenience store, for example, and houses a showcase body 6 having an opening 4 on the front surface, a condenser and a compressor constituting a refrigeration circuit (not shown), and will be described later. An refrigeration unit 8 to which a cooler 42 is connected is provided, and an electrical unit (control unit) 10 for managing and controlling the temperature, pressure, drainage status, etc. in the cabinet of the showcase 2 is provided above the showcase body 6. Is provided.

  The showcase main body 6 has its upper surface, bottom surface, and back surface covered with a heat insulating wall 12, and its left and right side surfaces are covered with side plates (not shown). The interior of the showcase body 6 is partitioned into an upper storage room (storage room) 16 and a lower storage room (predetermined storage room) 18 by a movable partition shelf 14, and each storage room 16, 18 has a different temperature. It is managed by. For example, the upper storage room 16 is set to about 15 ° C. for display of prepared foods, while the lower storage room 18 is set to about 20 ° C., which is higher than the upper storage room for displaying cooked rice. A two-temperature showcase 2 that can be displayed while being held at an appropriate temperature is configured. Each storage room 16 and 18 is provided with a product shelf 19 for displaying products.

  The showcase body 6 is formed with cold air passages 20, 30, and 40 along the top surface, bottom surface, and back surface, respectively. The upper surface side cold air passage 20 is formed in a gap between the heat insulating wall 12 and the upper surface plate 22 covering the upper surface side in the showcase body 6, and an air outlet 24 that opens downward from the opening 4 is formed at the front end thereof. A rectifying member 26 having a honeycomb structure is attached to the air outlet 24.

The bottom-side cold air passage 30 is formed with a suction port 32 that opens toward the upper side of the opening 4 at the front end thereof, and a fan 34 is provided at the approximate center in the front-rear direction of the bottom-side air passage 30.
The fan 34 is attached to the upper surface of a detachable fan duct 36 that extends in the front-rear direction of the bottom side ventilation path 30, and the rear end of the fan duct 36 communicates with the rear side ventilation path 40. The air sucked from the air and blown from the fan 34 is guided to the cooler 42 installed in the rear side air passage 40 through the fan duct 36.

  In addition, a drainage port 37 penetrating the heat insulating wall 12 is formed in the bottom side cold air passage 30 on the front side of the fan duct 36, and the drainage port 37 is covered with a mesh cover 38 for removing dust. The heat insulation wall 12 from the rear end side of the fan duct 36 to the drain outlet 37 is inclined downward, and a water guide gap 39 is cut out on the front end face of the fan duct 36 that contacts the heat insulation wall 12. The condensed water generated in the vessel 42 and the fan duct 36 flows down through the water guide gap 39 and is discharged from the drainage port 37 to the outside of the showcase body 6.

The back side cold air passage 40 is formed in a gap between the heat insulating wall 12 and the back plate 44 covering the back side in the showcase body 6 and communicates with the upper surface side cold air passage 20. Cooling is generated by the cooler 42, and the cool air is blown out from the outlet 24 through the upper surface side cool air passage 20.
Thus, the cold air blown out from the air outlet 24 is sucked in from the air inlet 32, so that an air curtain 50 is formed in the opening 4 to insulate the inside of the chamber from the outside. In other words, the cold air passages 20, 30, 40 are formed. Constitutes a main cold air passage 52 as a main cold air passage for forming the air curtain 50.

Here, in the showcase body 6, in addition to the main cold air passage 52, a part of the cold air forming the air curtain 50 is bypassed through the opening 4 in the front surface of the lower chamber 18 and is blown out through the cooler 42. A return cold air passage 60 for returning to 24 is formed.
Specifically, the inner partition shelf 14 is positioned slightly inside the imaginary straight line 54 that forms the flow path of the air curtain 50 whose front end substantially connects the air outlet 24 and the suction port 32. The formation of the air curtain 50 by the cold air passage 52 is not hindered.

  In addition, the inner partition shelf 14 has a hollow structure, and a second suction port 62 that opens upward from the opening 4 is formed at the front end thereof. An axial flow type return fan 66 for sucking a part of the cold air forming the air curtain 50 is provided at the center, and the hollow portion 64 communicates with a return duct 67 provided along the back side cold air passage 40.

  The return duct 67 is formed by partitioning the back side cold air passage 40 between the back plate 44 and the heat insulating wall 12, that is, the first partition plate 68 extending over the vertically movable range of the inner partition shelf 14, The lower opening 67a is opened to the bottom surface side cold air passage 30, and the hollow portion 64 and the bottom surface side cold air passage 30 are communicated with each other. Thus, the cool air blown from the return fan 66 is guided to the fan 34, and a part of the cool air forming the air curtain 50, that is, the air leaking from the air curtain 50 is bypassed through the opening 4 in the front surface of the lower chamber 18. Then, the air is returned to the air outlet 24 via the cooler 42, thereby forming a return cold air passage 60.

By the way, the main cold air passage 52 and the return cold air passage 60 are formed as shown by the solid arrow in FIG. 1, and the hot air is sent from the back surface 18 a of the lower chamber 18 as shown by the dotted arrow in FIG. 1. A hot air passage 70 for blowing out is formed.
In the hot air passage 70, the cool air sucked from the third suction port 72 formed inside the storage chamber 32 from the suction port 32 at the front end of the bottom side cold air passage 30 is turned into warm air by the heater unit 73 and is adjacent to the product in the vertical direction. The air is blown out from a hot air outlet 74 formed at a substantially middle position of the shelf 19.

  In addition to the heater unit 73, the warm air passage 70 draws a part of the cold air forming the air curtain 50 from the third suction port 72, that is, the temperature at which the air leaking from the main cold air passage 52 is sucked into the heater unit 73. A wind fan 75 is arranged. The heater unit 73 and the warm air fan 75 are accommodated in the warm air fan duct 76, and the warm air fan duct 76 is disposed on the upper side of the fan duct 36 and communicates with the third suction port 72. Further, the hot air fan duct 76 communicates with a hot air duct 77 provided along the back side cold air passage 40, and the hot air formed from the hot air fan 75 via the heater unit 73 passes through the hot air duct 77. To the hot air outlet 74.

The hot air duct 77 is formed by partitioning the inner side of the back plate 44 with a second partition plate 78 extending over the vertically movable range of the middle partition shelf 14, and the second partition plate 78 has the above-described temperature. An air outlet 74 is formed.
Here, in this embodiment, the 1st thermistor (cold air temperature detection means) which is provided in the warm air fan duct 76, detects the temperature of the cold air sucked from the 3rd inlet 72 and used for formation of warm air. 80, a second thermistor (warehouse temperature detecting means) 82 that is provided on the back surface 18a of the lower compartment 18 and detects the temperature in the lower compartment 18; a hot air duct 77; And a third thermistor (warm air temperature detecting means) 84 for detecting the temperature of the hot air before being blown out from the air. A fourth thermistor 86 is provided for detecting the temperature.

  In addition to these thermistors 80 to 86, although not explicitly shown, a heater 88 that is a heating part of the heater unit 73 and a hot air fan motor 90 that is a driving part of the hot air fan 75 (hereinafter referred to as hot air FM). A return fan motor 92 (hereinafter referred to as a return FM) that is a drive unit of the return fan 66 is electrically connected to the electrical unit 10. And in the electrical equipment unit 10, in order to hold | maintain the temperature in the lower chamber 18 appropriately by starting or stopping each FM90,92 and the heater 88 according to the temperature detected by each thermistor 80-86. The storage room temperature is controlled.

Hereinafter, with reference to the flowchart shown in FIG. 2, the control routine of the compartment temperature control performed in the electrical unit 10 will be described in detail.
First, when the temperature control is started, the process proceeds to S1 (hereinafter, S represents a step).
In S1, the third suction port 72 is cold air temperature _{T 1} of the cold air sucked from the set temperature _{T S1} detected in the first thermistor 80 (e.g. 20 ° C.), securing a predetermined tolerance of the set temperature _{T S1} It is determined whether or not the temperature difference T _DEF1 (for example, 2 ° C.) set to be equal to or lower than an allowable temperature (T _S1 −T _DEF1 ). If the determination result is true (Yes) and it is determined that T ₁ ≦ (T _S1 −T _DEF1 ) is established, the process _{proceeds to S} 2, and the determination result is false (No) and T ₁ ≦ (T _S1 −T _{DEF 1} ). If it is determined that is not established, the process proceeds to S3.

When the process proceeds to S2, the FMs 90 and 92 are started, the heater 88 is stopped, and the process proceeds to S4.
In S4, from the lower chamber compartment refrigerator compartment temperature T ₂ within 18 whose set temperature T _S2 detected at the second thermistor 82 _(e.g. 22 ° C.), it is set so as to ensure a predetermined tolerance range of the set temperature T _S2 It is determined whether the temperature difference is equal to or less than the allowable temperature (T _S2 −T _DEF2 ) _obtained by subtracting the temperature difference T _DEF2 (for example, 2 ° C.). If it is determined that T ₂ ≦ (T _S2 −T _DEF2 ) is true when the determination result is true (Yes), the _{process proceeds} to S5, and the determination result is false (No) and T ₂ ≦ (T _S2 −T _DEF2 ). When it is determined that is not established, the process returns to S1 and enters the next cycle of the present control routine.

When the process proceeds to S5, the heater 88 is activated while the FMs 90 and 92 are activated, and the process proceeds to S6.
If the routine moves to step S6, it is determined whether a third hot air temperature T ₃ is the set temperature T _S3 in warm air duct 77 to be detected in the thermistor 84 _(e.g. 40 ° C.) or higher. If it is determined that T ₃ ≧ T _S3 is satisfied when the determination result is true (Yes), the process returns to S2 and only the heater 88 is stopped. If the determination result is false (No) and T ₃ ≧ T _S3 is not satisfied. again a determination of the cold storage compartment temperature T ₂ back to step S4 if it is determined.

On the other hand, when a transition to step S3 from S1 decides whether or not the cold air temperatures T ₁ is the set temperature T _S1 more. If the determination result is true (Yes) and it is determined that T ₁ ≧ T _S1 is satisfied, the process proceeds to S7, and if the determination result is false (No) and it is determined that T ₁ ≧ T _S1 is not satisfied, The process proceeds to S8.
When the process _proceeds to S7, it is determined whether or not T ₂ ≦ (T _S2 −T _DEF2 ) is satisfied, similarly to the determination in S4. If it is determined that T ₂ ≦ (T _S2 −T _DEF2 ) is true when the determination result is true (Yes), the _{process proceeds} to S 9, and the determination result is false (No) and T ₂ ≦ (T _S2 −T _{DEF 2} ). When it is determined that is not established, the process proceeds to S8.

When the process proceeds to S9, each FM 90, 92 is activated, the heater 88 is stopped, and the process proceeds to S10.
In S10, the refrigerator compartment temperature _{T 2} is equal to or its set temperature _{T S2} less either. If the determination result is true (Yes) and it is determined that T ₂ ≦ T _S2 is satisfied, the process returns to S1 to enter the next cycle of this control routine, and the determination result is false (No) and T ₂ ≦ T _S2 is satisfied. If it is determined not to do so, the process proceeds to S8.

When the process proceeds from S3, S7, and S10 to S8, the FMs 90 and 92 and the heater 88 are stopped, and then the process returns to S1 to enter the next cycle of this control routine.
Thus, in the storage room temperature control, the storage room temperature T ₂ is adjusted so as to satisfy (T _S2 −T _DEF2 ) ≦ T ₂ ≦ T _S2 regardless of the in-store temperature.
In the present embodiment, in response to cold temperatures T _1, the low temperature mode store temperature, high temperature mode, is determined to be either mesophilic mode, S1, S3 step, cold air temperature T ₁ is the It is positioned as a branch point that fluctuates across the set temperature T _S1 and its allowable temperature (T _S1 -T _DEF1 ), and each mode is switched every period of this control routine.

Specifically, if T ₁ ≦ (T _S1 −T _DEF1 ) is established in _S1 , it is determined that the in-store temperature is in the low temperature mode, and in this case, steps S2, S4 to S6 are executed. by, with starting each FM90,92, when to start or stop the heater 88 in accordance with the refrigerator compartment temperature _{T 2,} the hot air temperature _{T 3} rises to the set temperature _{T S3} above, kill the heater 88 is doing.

On the other hand, if T ₁ ≦ (T _S1 −T _DEF1 ) is not satisfied in _{S1, and} if T ₁ ≧ T _S1 is satisfied in S3, it is determined that the in-store temperature is in the high temperature mode. the, by performing the steps of S7 to S10, the heater 88 is stopped with starting each FM90,92, then Kurashitsu temperature _{T 2} is switched to the larger the intermediate temperature mode than the set temperature _{T S2.}

The medium temperature mode is selected when T ₁ ≦ (T _S1 −T _DEF1 ) does not hold at _{S1 and} T ₁ ≧ T _S1 does not hold at S3 in addition to switching from the high temperature mode. Only the step of S8 is executed, and the FMs 90 and 92 and the heater 88 are stopped.
As described above, in the present embodiment, as described, not only the refrigerator compartment temperature T _2, the influence of in-store temperature in air curtain 50, and the cold air temperature T ₁ of the cold air to be used further for the formation of hot air, warm air blowing port since the hot air temperature T ₃ of hot air before being blown out of 74 can be performed considering to cold storage compartment temperature control in advance, and improving the responsiveness of the cold storage compartment temperature control, significantly improve the controllability can do. Therefore, for example, in the case of excessive cooling in the store in winter or summer, for example, even if the store temperature is a low temperature of 15 ° C. or less, which is the set temperature of the upper chamber 16, for example, regardless of the store temperature, lunch which is possible to hold the refrigerator compartment temperature T ₂ of the lower chamber compartment 18 to approximately 20 ° C. which is the set temperature T _S2 can be displayed on the commodity shelf 19 of the lower chamber chamber 18 by blowing of cold air and thus the low temperature It is possible to prevent the moisture of the cooked rice from evaporating and drying, and to properly manage the quality of the products displayed on the product shelf 19.

Further, it is determined in accordance with the cold air temperatures T ₁ detected by the first thermistor 80, store temperature low mode, the high temperature mode, or whether the one of the intermediate temperature mode through the time of switching between these modes it allows store temperature grasped through the cold air temperatures T ₁ is divided into the mode, it is possible to perform an optimum cold storage compartment temperature control in each mode, further improving the controllability of the cold storage compartment temperature control be able to.

In particular, in the steps of S1 and S7, by using the allowable temperature (T _S1 -T _DEF1 ) and (T _S2 -T _DEF2 ) as the determination criteria for mode switching, the variation in the cold air temperature T ₁ and the chamber temperature T ₂ is changed. Therefore, the mode switching can be smoothly performed by suppressing the hunting phenomenon of the mode switching, and the controllability of the chamber temperature control can be further improved.
Specifically, when the store temperature is determined to be in the low temperature mode, each with FM90,92 is activated, since the heater 88 according to the refrigerator compartment temperature T ₂ is started or stopped, the lower compartment chamber The interior 18 can be rapidly warmed with warm air to quickly prevent the store room temperature T ₂ from decreasing due to a decrease in store temperature, and hot air and cold air can be used separately according to the store room temperature T _2. Can do.

Further, when in the low temperature mode, when the hot air temperature T ₃ rises to the set temperature T _S3 or higher, the heater 88 is stopped, so that the warm air temperature T of the hot air before being blown into the lower chamber 18 is reached. it is possible to selectively use the warm air and cold air in accordance with _3, these, the lower compartment chamber 18 can be maintained in a proper temperature in a state of enhanced control response, the controllability of the cold storage compartment temperature control Further improvement can be achieved.

Furthermore, when it is determined that the in-store temperature is in the high temperature mode, the FMs 90 and 92 are activated and the heater 88 is stopped. it is possible to prevent an increase of the cold storage compartment temperature T ₂ with increasing temperature quickly, can hold the lower compartment chamber 18 to a proper temperature in a state of further enhanced control response, cold storage compartment temperature Controllability of control can be further improved.

Also, store temperature mesophilic mode, i.e., when the refrigerator compartment temperature T ₂ is determined is the optimum temperature, in addition to the heater 88, the FM90,92 also stopped, the cold air in the return Reifuro 60, and Yutakakazero 70 Does not form hot air in Thereby, the air curtain 50 in which the cold air temperature and the amount of cold air are substantially constant is formed on the front surface of the lower chamber 18, and the chamber temperature T ₂ can be kept substantially constant as it is. The property can be further improved.

The description of one embodiment of the present invention is finished above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the two-temperature open showcase 2 has been described. For example, the position of the partition 14 can be changed in three or more stages, or a plurality of returns can be provided by providing a plurality of partitions 14. The cool air passage 60 may be formed, or the hot air passage 70 capable of forming warm air in a plurality of temperature zones may be formed to partition the interior into three or more, and the temperature may be individually controlled. In this case as well, by performing the storage room temperature control, the temperature of each storage room can be appropriately maintained regardless of the in-store temperature.

In the above embodiment, the cold air temperature T ₁ detected by the first thermistor 80 determines whether the in-store temperature is in the low temperature, medium temperature, or high temperature mode, but is detected by the fourth thermistor 86. the actual store temperature (environmental temperature) T ₄ in consideration of the may be performed to switch the modes that, in this case, considering the variation of the in-store temperature T ₄ which is a main cause of the variation of the cold air temperatures T ₁ Since the mode can be switched, the controllability of the chamber temperature control can be further improved.

It is side surface sectional drawing of the open showcase which concerns on one Embodiment of this invention. It is the flowchart which showed the control routine of the chamber temperature control performed with the electrical equipment unit of FIG.

Explanation of symbols

2 Open showcase 4 Opening 6 Showcase body 10 Electrical unit (control unit)
14 Partition shelf 16 Upper storage room (storage room)
18 Lower room (predetermined room)
18a Rear surface 24 Air outlet 32 Air inlet 50 Air curtain 52 Main cold air passage 60 Return cold air passage 70 Hot air passage 74 Hot air outlet 80 First thermistor (cool air temperature detecting means)
82 Second thermistor (room temperature detection means)
84 Third thermistor (hot air temperature detection means)
88 Heater (Heater unit)
90 Hot air fan motor (hot air fan)
92 Return fan motor (return fan)

Claims (7)

A showcase main body having an opening on the front surface, a partition shelf for partitioning the interior of the showcase main body into a storage room having different temperatures, and a main cold air passage formed along the top surface, the back surface, and the bottom surface of the showcase main body And a fan disposed in the bottom-side cold air passage, and a cooler disposed in the back-side cold air passage, and the air in the bottom-side cold air passage passes through the fan by the cooler After being cooled and blown out from the air outlet formed at the front end of the upper surface side cold air path, the air curtain is sucked into the opening by being sucked from the suction port formed at the front end of the bottom surface side cold air path. An open showcase that forms a
A return fan for sucking a part of the cold air forming the air curtain, and returning the sucked cold air to the cooler by bypassing the front surface of a predetermined chamber among the chambers;
A hot air blowout port is provided that has a hot air fan that draws a part of the cold air forming the air curtain and heats it with a heater unit to form hot air, and the hot air is formed on the back of the predetermined chamber A hot air passage that blows out from
Chamber temperature detecting means for detecting the temperature of the predetermined chamber;
Cold air temperature detecting means for detecting the temperature of the cold air;
Hot air temperature detecting means for detecting the temperature of the hot air before being blown out from the hot air outlet;
The return fan, the hot air fan, and the heater unit are started or stopped according to the temperatures detected by the temperature detection means, and the warehouse temperature detected by the warehouse temperature detection means is set to a predetermined value. An open showcase comprising a control unit that holds the temperature substantially constant.   Whether the cold air temperature detected by the cold air temperature detecting means is equal to or lower than an allowable temperature obtained by subtracting a temperature difference set to ensure a predetermined allowable range of the set temperature from the set temperature. If the cold air temperature is equal to or lower than the allowable temperature, the environmental temperature in which the open showcase is installed is determined to be a low temperature mode, and the cold air temperature is equal to or higher than the set temperature. The environmental temperature is determined as a high temperature mode, and when the cold air temperature is higher than the allowable temperature and lower than the set temperature, the environmental temperature is determined as an intermediate temperature mode. Open showcase.   When it is determined that the environmental temperature is in the low temperature mode, the control unit activates the return fan and the warm air fan and activates or stops the heater unit according to the chamber temperature. The open showcase according to claim 2, wherein the open showcase is characterized.   4. The open show according to claim 2, wherein the control unit starts or stops the heater unit according to the hot air temperature when it is determined that the environmental temperature is in the low temperature mode. 5. Case.   5. The control unit according to claim 2, wherein when the environmental temperature is determined to be in the high temperature mode, the control unit starts the return fan and the hot air fan and stops the heater unit. Open showcase described in crab.   6. The control unit according to claim 2, wherein the control unit stops the return fan, the heater unit, and the heater unit when it is determined that the environmental temperature is in the intermediate temperature mode. Open showcase. Environmental temperature detection means for detecting the environmental temperature,
7. The control unit according to claim 2, wherein the control unit performs mode switching between the low temperature mode, the medium temperature mode, and the high temperature mode according to the environmental temperature detected by the environmental temperature detection means. Open showcase described in.

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