JPH01159575A - Temperature control system in refrigerating or freezing showcase - Google Patents

Abstract

PURPOSE: To prevent articles to be cooled from being excessively cooled by altering a set value of temperature of a show case in response to the amount of light of a refrigerator illumination light. CONSTITUTION: A switching circuit 3 is driven by an output of an optical detection device 2 for detecting a light amount of a refrigerator illumination light, and is closed to shortcircuit a resistor 4 when the refrigerator illumination light is extinguished with completion of a business. Reference voltage for setting chamber temperature from a tap of the resistor 5 of a voltage division circuit is lowered by the shortcircuitting of the resistor 4, and hereby a set value of the refrigerator temperature is altered to a higher value. Hereby, when a refrigerator illumination light of a show case is extinguished upon completion of a business, the chamber temperature is automatically kept at a higher value so that an article to be refrigerated is prevented from being overcooled.

Description

[Detailed Description of the Invention] [Summary] A light receiving element is provided to detect the amount of light from an interior lighting lamp installed in a refrigerating or freezing showcase, and the showcase is set by an output corresponding to the amount of light detected by this light receiving element. The temperature was changed to reduce power consumption during non-business hours.

[Industrial Field of Application] The present invention relates to a temperature control system for open showcases installed in, for example, supermarkets for refrigerating or freezing foods.

[Conventional technology] Conventionally, during business hours, air curtains are used to reduce the flow and flow of heat from the openings of oven showcases, but during non-business hours, it is necessary to set a night cover. The conditions for heat outflow and inflow change,
Problems such as overcooling may occur.

In addition, during non-business hours of the store, it is required to raise the set temperature of refrigeration and freezing in the showcase to a level that does not adversely affect the quality of the refrigerated and frozen products in the store, thereby reducing power consumption. It is now possible to do so.

[Problems to be solved by the invention] The above-mentioned problems with conventional refrigerated or frozen showcases are such that the showcases cannot be refrigerated or refrigerated at the end of business hours.
This problem can be solved by increasing the set value of the freezing temperature, but the set value is often not manipulated because it is inconvenient or simply forgotten.

The present invention aims to eliminate this problem by automatically changing the set temperature.

Means for Solving Problems] As shown in the embodiment shown in the attached drawings, there is a light receiving element 2 that detects the amount of light from an interior lighting lamp installed in a refrigerator or freezer showcase, and a Means 3 for changing the set value of the temperature of the showcase according to the output according to the amount of light is provided.

The detailed functions and operations of the refrigerating/freezing temperature setting means 3 in the illustrated embodiment will be described later.

[Function] If the interior lighting lights installed in a refrigerator or freezer showcase are turned on, they will be easily noticed by employees due to their brightness, and they will not forget to turn them off at the end of business hours.

In the present invention, the light-receiving element 2 detects the lighting state of the interior lighting, and when the interior lighting is turned off, the means 3 for changing the showcase temperature setting is controlled by the output of the light-receiving element. The above problem was solved by increasing the set temperature of the showcase.

[Embodiment] In the attached drawings showing an embodiment of the present invention, 1 is a temperature detection element such as a thermistor that detects the temperature inside the showcase, and 2 is a light receiving element such as a phototransistor that detects the amount of light from a lighting lamp inside the refrigerator. 3 is a switching circuit as a means for changing the set value of the temperature driven by the output of this light receiving element, 4.5 and 10 are resistors for dividing the power supply voltage, 6 is a comparison circuit, and 7 is for controlling the refrigerator. A drive circuit for the relay 8, 9 is a power supply section.

The other components except for the light receiving element 2 and the switching circuit 3 added according to the present invention constitute a normal refrigerator temperature control device, and the temperature detection element 1 converts the refrigerator temperature into an analog voltage. Analog voltage is connected to resistor 4. 5. The comparator circuit 6 compares the temperature with a reference voltage for setting the internal temperature from the tap of the resistor 5 of the voltage dividing circuit 10.

If the temperature inside the refrigerator is higher than the set value and the analog voltage from the temperature detection element 1 is lower than the reference voltage, the output from the comparison circuit 6 is sent to the contact of the refrigerator control relay 8 via the relay drive circuit 7. is closed to start the refrigerator and lower the temperature inside the refrigerator. Also, when the temperature inside the refrigerator is lower than the set value and the analog voltage from the temperature detection element 1 is higher than the reference voltage, this comparison circuit 6 Since no output is generated, the refrigerator is not driven.

The light-receiving element 2, such as a phototransistor, which detects the light intensity of the interior lighting lamp of the showcase added according to the present invention, opens the switching circuit 3 by its output when the interior lighting lamp is turned on. The normal temperature control described above is performed.

When the interior lighting is turned off due to the end of business hours, etc., the light-receiving element 2 will no longer generate an output, so the output of the light-receiving element will close the switching circuit 3, which was in an open state, and short-circuit the resistor 4. As a result, the reference voltage for setting the temperature inside the refrigerator from the tap of the resistor 5 of the voltage dividing circuit decreases, and the set value of the temperature inside the refrigerator is changed to a higher value.

As a result, when the analog voltage from the temperature detection element 1 becomes lower than when the above-mentioned interior light is on, that is, the temperature inside the refrigerator is lower than when the interior light is on. When the temperature rises and the resistance value of the temperature detection element 1 further decreases, the refrigerator is started to be driven.
The temperature inside the showcase is maintained at a higher temperature than when the interior lighting lamp is turned on.

[Effects of the Invention] According to the present invention, by turning off the interior lighting of the showcase at the end of business hours, the temperature inside the refrigerator is automatically maintained at a high value. Since it is practically impossible to forget to turn off the lighting, it is possible to solve the problem of overcooling refrigerated items, which is the case when manually changing the temperature setting as in the past.

In particular, if power is supplied to the showcase temperature control device and refrigerator from the power line, and power to the interior lighting is supplied from the power line, it is necessary to operate the devices connected to the power line. It is safe because there are no wires, and the special effect of simplifying the wiring of these power supplies can be achieved.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention. 2... Light-receiving element that detects the amount of light from the interior lighting lamp, 3...
- A switching circuit as a means for changing the temperature set value of the showcase according to the output according to the amount of light detected by this light receiving element. Patent applicant: Saginomiya Seisakusho Co., Ltd.

Claims (1)

[Claims] A light-receiving element that detects the light intensity of an interior lighting lamp installed in a refrigerator or freezing showcase, and a set value of the temperature of the showcase is changed by an output corresponding to the light intensity of the interior lighting lamp detected by this light-receiving element. 1. A temperature control system in a refrigerated or frozen showcase, characterized by comprising means.