JPH1099167A - Control device of open showcase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an open showcase control system to control temperatures close to a temperature detected by a temperature sensor in a normal condition, using a substitute sensor eve in the event of the failure of the temperature sensor. SOLUTION: In the event of the failure of either of sensors 1a to 1d due to disconnection or a short circuit, a temperature control mechanism 5 detects it, feeding the kind of the failed sensor and the kinds of a showcase to a temperature data shift control mechanism 14. Depending on the data fed, the temperature data shift control mechanism 14 reads from a type-dependent temperature shift data storage mechanism 16 a substitute sensor and the amount of temperature shit for correcting temperature to the temperature near the place of installation of the failed sensor, and feeds them to a sensor input switching mechanism 3. The data is received by a temperature control mechanism 5, which in turn feeds predetermined temperature regulating and defrosting control outputs respectively to temperature regulating valves 12a, b and a defrosting heater 13 via an output switching mechanism 6. Therefore, control can be performed at almost the same temperature whether the sensor is in trouble or in a normal condition, preventing decrease in the freshness of products and formation of ice banks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a cold air circulation type open showcase.

[0002]

2. Description of the Related Art Conventionally, an open showcase is provided with a temperature control sensor such as a temperature control sensor (hereinafter referred to as a temperature control sensor), a defrost sensor, and a sensor in a refrigerator. On the other hand, for example, when the temperature control sensor is abnormal, temperature control is performed by a cycle operation that turns on and off the cool air supply valve at regular intervals so that the operation can be continued even if an abnormality such as disconnection or short circuit occurs in these sensors. When the frost sensor is abnormal, so-called safe-time defrosting is performed in which the defrosting is restored after a certain period of time. In addition, there is a device that performs a defrost recovery control based on the temperature data by using a temperature control sensor instead of the defrost sensor when the defrost sensor is abnormal.

[0003]

The conventional open showcase control device has the following problems. As described above, when the cycle operation is performed at the time of the sensor abnormality, only the cold air supply valve is turned on and off at predetermined time intervals, and the temperature inside the showcase is not taken into consideration, so that accurate temperature control cannot be performed. Therefore, this control is not suitable for, for example, products that require accurate temperature control to maintain freshness.

When the defrost recovery control is performed based on the temperature data of the substitute temperature control sensor when the defrost sensor is abnormal, the detection temperature is also different because the temperature control sensor and the defrost sensor are usually installed at different locations. The frost return time is different from when using the normal defrost sensor. As a result, if the return time is too early, the temperature control is started before the frost is sufficiently melted, so that a so-called ice bank is easily generated. Conversely, if the return time is too slow, the temperature inside the refrigerator may increase, and the freshness of the product may be reduced.

[0005] Further, regarding safe time defrosting, although the inside temperature rise gradient is different because the structure of the showcase differs for each model, the safe time is set to the same value, so that the temperature inside the refrigerator is too high. The product freshness sometimes dropped. An object of the present invention is to make it possible to perform control at a temperature close to the temperature detected when the control temperature sensor becomes abnormal when the control temperature sensor becomes abnormal.

[0006]

An open showcase control device according to the present invention is an open showcase control device for controlling operation based on temperature data from a plurality of temperature sensors. Input means for inputting temperature data from a predetermined sensor other than the abnormal sensor as a substitute for the temperature data of the abnormal sensor when the sensor is abnormal, and correcting means for correcting the temperature data from the substitute sensor to an approximate temperature of the abnormal sensor installation location And

Accordingly, when the temperature sensor is abnormal, the temperature input data required for the temperature control and defrosting control is corrected by the correction means to the normal detected temperature, so that the control is performed at a temperature close to the normal temperature of the sensor. Is performed. In addition, for the combination of the abnormal sensors, a storage unit that stores a substitute sensor and its temperature correction value for each model of the showcase is provided. When the sensor is abnormal, the correction unit stores the temperature correction value of the substitute sensor by the storage unit. It may be read and corrected.

[0008] With this, when a sensor abnormality occurs, control can be performed by using a predetermined substitute sensor and a temperature correction value corresponding to the model of the showcase, so that control is performed at a temperature close to the detected temperature when the sensor is normal. Further, a data input unit may be provided for inputting and storing the substitute sensor and its temperature correction value for each combination of the abnormal sensors for each showcase model in the storage unit.

Thus, even when the model of the showcase is changed or the temperature in the refrigerator is changed, the data for the sensor abnormality can be easily changed.

[0010]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention. 1a, 1b, 1c, 1d
Are an internal temperature sensor, a temperature control sensor, a defrost sensor, and an external temperature sensor, respectively. This sensor is usually input from a plurality of show cases, but only one set is shown in the figure. The temperature data detected by each sensor is input to the sensor input switching mechanism 3 via the sensor input mechanism 2. The input temperature data is data in which the installation location and use of each sensor are identified by the model type setting mechanism 4 corresponding to the model of the showcase.

Reference numeral 5 denotes a temperature control mechanism for controlling the entire apparatus, which receives the identification data from the sensor input switching mechanism 3, performs temperature control and defrost control based on this data, and switches the control output to an output. Send to mechanism 6. Output switching mechanism 6
Assigns the purpose of the control output in accordance with the model of the showcase identified by the model type setting mechanism 4 and sends it to the output units 7a, 7b and 7c, respectively. The temperature control valves 12a and 12b and the defrost heater 13 are controlled by the allocated signals.

A temperature display mechanism 8 is connected to the temperature control mechanism 5. This temperature display mechanism 8 is provided with a temperature sensor 1
Based on the detected temperature data of a, 1b, 1c and 1d, display temperature data such as the inside temperature of the showcase is generated. A display output destination of the temperature data is selected by the display selection output mechanism 10, and is displayed on the selected display output destination 11a or 11b.

The above is the operation of the conventional showcase control device when each sensor is normal. In the present invention, a temperature data shift control mechanism 14, a temperature shift input mechanism 15, and a model type-specific temperature shift amount data storage mechanism 16 having the functions described below are further added. Next, the operation of the showcase control device according to the present invention will be described.

When the temperature control mechanism 5 detects an abnormality of the temperature control sensor 1b or the defrost sensor 1c, for example, disconnection or short circuit of the sensor, the type of the showcase and the type of the abnormal sensor (hereinafter referred to as abnormal sensor information data) ) Is sent to the temperature data shift control mechanism 14. When this data is received by the temperature data shift control mechanism 14, based on the received abnormal sensor information data, the substitute sensor and the temperature shift amount corresponding to the model are read out from the model type temperature shift amount data storage mechanism 16. , The temperature shift amount is added to the temperature data of the substitute sensor. Further, the added temperature data (temperature processing value) is transmitted to the sensor input switching mechanism 3. This temperature processing value is received by the temperature control mechanism 5,
As described above, temperature control or defrost recovery control is performed.

FIG. 2 shows an example of data stored in the above-described temperature shift amount data storage mechanism 16 for each model type. That is, the type of the sensor (substitute sensor) used for each of the temperature control, the defrosting control, and the display in the refrigerator corresponding to the sensor in which the abnormality has occurred (the abnormality sensor) and the temperature shift amount described above are shown. ing. Here, as described above, since the installation location of each sensor differs depending on the model of the showcase, it is necessary to determine the temperature shift amount for each model of the showcase in consideration of this.

FIGS. 4, 5, and 6 are views showing examples of locations where the sensors are installed for the models A, B, and C. FIG. For example, model B
In this case, the temperature control sensor 1b and the defrost sensor 1c are close to each other, but are separated in the model A. Therefore, the temperature shift amount of the temperature control sensor 1b used when the defrost sensor 1c is abnormal is slightly higher in the model A. In the case of model B, the settings are almost the same. FIG.
Shows numerical examples of the respective temperature shift amounts shown in FIG. 2 for each of the above showcase models A, B, and C. These data are stored in the type-specific temperature shift amount data storage mechanism 16.

Further, in the present invention (FIG. 1), for example, data of a new model can be additionally registered in the temperature shift amount data storage mechanism 16 for each model type, or the model can be changed so that the inside temperature can be further changed to an appropriate temperature. A temperature shift input mechanism 15 for inputting each corresponding temperature shift amount is provided. By the above operation, when the control temperature sensor becomes abnormal, control is performed by a processing value obtained by adding or subtracting the temperature shift amount to or from the substitute sensor, so that control can be performed at a temperature close to the detected temperature when the sensor is normal.

[0018]

According to the present invention, when a temperature sensor is abnormal, even if a substitute sensor is used, the temperature data necessary for the temperature control and the defrosting control can be corrected by the correction means to a temperature close to the temperature detected when the sensor is normal. , Cooling and defrosting can be performed with relatively high accuracy even when the sensor is abnormal.

If the substitute sensor and the temperature correction value are stored for each model of the showcase with respect to the combination of the abnormal sensors, the internal temperature of each model can be maintained at substantially the same temperature as when the sensor is normal. Therefore, even when the sensor is abnormal, there is no possibility that the freshness of the product is reduced. Also, as for the defrost recovery control, since the defrost recovery control can be performed at a temperature close to the defrost temperature when the sensor is normal, there is no risk of occurrence of an ice bank or a reduction in freshness of a product.

Further, if a data input means is provided for inputting and storing the substitute sensor and its temperature correction value for each showcase model for the abnormal sensor in the storage means,
Data can be easily changed when the model of the showcase is changed or when the temperature in the refrigerator is changed.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a substitute sensor and a temperature shift amount for an abnormal sensor;

FIG. 3 is a diagram illustrating a temperature shift amount for each model;

FIG. 4 is a view showing a sensor installation location of a model A;

FIG. 5 is a diagram showing a sensor installation location of a model B;

FIG. 6 is a diagram showing a sensor installation location of a model C;

[Explanation of symbols]

1a: Internal temperature sensor, 1b: Temperature control sensor, 1c: Defrosting sensor, 1d: External temperature sensor, 2: Sensor input mechanism, 3 ...
Sensor input switching mechanism, 4 model type setting mechanism, 5 temperature control mechanism, 6 output switching mechanism, 7a output sections 1 and 7b
... Output units 2, 7c ... Output units 3, 8 ... Temperature display mechanism, 9 ...
Display data output mechanism, 10 ... Display selection output mechanism, 11
a, 11b: display, 12a, 12b: temperature adjustment valve, 13: defrost heater, 14: temperature data shift control mechanism, 15: temperature shift input mechanism, 16: temperature shift amount data storage mechanism by model type.

Claims (3)

[Claims] An open showcase control device for performing operation control based on temperature data from a plurality of temperature sensors, wherein when one or more sensors are abnormal, the temperature data from a predetermined sensor other than the abnormal sensor is output. An input means for inputting the temperature data of the abnormal sensor as a substitute, and a correcting means for correcting the temperature data from the substitute sensor to an approximate temperature of the installation location of the abnormal sensor. . 2. The control device according to claim 1, further comprising: storage means for storing a substitute sensor and a temperature correction value for each combination of the abnormality sensors for each model of the showcase. Is a control device for an open showcase, wherein a temperature correction value of a substitute sensor is read out and corrected by a storage means. 3. The control device according to claim 2, further comprising data input means for inputting and storing, in the storage means, a substitute sensor and its temperature correction value for each combination of the abnormal sensors for each showcase model. And open showcase control device.