JPS5994041A - Apparatus for detecting frost - Google Patents

Abstract

PURPOSE:To accurately detect the adhesion of frost to a fin plate in a simple manner, by providing a light emitting element and a light receiving element at a position spaced apart from the fin plate end edge of a heat exchanger over a predetermined distance. CONSTITUTION:A light emitting element 8 and a light receiving element 9 are provided at a position in parallel to the arrangement direction of fin plates 6 so as to be spaced apart from the end edges of the fin plates 6 of a heat exchanger 5 and the irradiation light of the element 8 is blocked by frost of each fin plate 6 and frost adhesion is detected through the element 9. As mentioned above, by providing constitution wherein it is unnecessary to drill the hole for forming the light path to the fin 6, frost adhesion can be accurately detected without hindrance for disturbing the cooling action of the fin plate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for detecting that a predetermined amount or more of frost has formed on a heat exchanger of a refrigerator or the like.

Conventional configurations and their problems In heat exchangers for refrigerators and freezers, moisture inside the refrigerator often turns into frost and adheres to fin plates, etc. during use, and heat exchange efficiency is affected by a large amount of frost adhering to the heat exchanger. will decrease. For this reason, it is necessary to constantly detect the state of frost adhesion to the fin plate, and when a predetermined amount or more of frost has adhered, the cooling operation must be temporarily stopped to defrost the fin plate.

A frost detection device that has been conventionally used for this purpose is, for example, the one shown in FIG. A light source 3 and a light receiving element 4 are provided, and when a large amount of frost adheres to the fin plate 1 and the hole 2 is blocked, the light from the light source 3 will not reach the light receiving element 4. This detects whether a large amount of frost has accumulated.

However, in a general heat exchanger, only one fin plate 1 is used, as shown in FIG. . Therefore, it is difficult to arrange the light source 3 and the light receiving element 4 above and below the hole 2. In particular, if the light source 3 is placed close to the fin plate 1, the heat generated there will cause frost to form in the hole 2. The adhesion state has changed,
Accurate detection becomes impossible. Furthermore, even if only one fin plate 1 is extended laterally for detection, the state of frost adhesion on the detection area will be significantly different from that on other areas, making accurate detection impossible. There was a drawback.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an apparatus that can overcome the above-mentioned conventional drawbacks and accurately detect the state of frost on a heat exchanger having a plurality of fin plates.

Structure of the Invention In order to achieve the above object, the frost detection device of the present invention includes a heat exchanger having a plurality of fin plates arranged one on top of the other with a predetermined interval, and the edges of the plurality of fin plates A light source and a light receiving element for receiving light from the light source are provided at a position apart from the edge by a predetermined distance and parallel to the arrangement direction of the fin plates, and frost attached to the fin plates prevents the light from being received from the light source. This is so that light to the element is blocked.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to FIGS. 2 and 3. In the figure, 15 is a heat exchanger such as a refrigerator, which has a plurality of fin plates 6 arranged one above the other in the vertical direction at predetermined intervals. 7
is the refrigerant pipe. In order to detect frost, a light source 8 and a light receiving element 9 are vertically positioned relative to each other at a position a predetermined distance away from the edge of the plurality of fin plates 6 and parallel to the arrangement direction of the fin plates 6. With this configuration, as shown in FIG. 3, when no frost 1o is attached to the fin plate 6, the light from the light source 8 is directly received by the light receiving element 9, and the frost is removed. 10
It is detected that there is no adhesion. On the other hand, the third
As shown by the broken line in the figure, when a large amount of frost 1o adheres to the fin plate 6, a part of it starts to protrude laterally from the edge of the fin plate 6, and when more than a predetermined amount of frost 1o adheres, When the light from the light source 8 is blocked, the light receiving element 9
light will no longer reach. Therefore, this light receiving element 9
The adhesion of frost 10 is detected by the interruption of light reception at .

Effects of the Invention In this way, according to the frost detection device of the present invention, it is possible to easily detect the state of frost adhesion in a heat exchanger in which a large number of fin plates are stacked. Moreover, there is no need to bring the light source closer to the fin plate than necessary or to extend only a specific fin plate, so the cooling effect of the fin plate is not disturbed, and the fin plate remains in the predetermined shape. It is possible to accurately detect the adhesion state of.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional frost detection device, FIG. 2 is a perspective view of a frost detection device according to an embodiment of the present invention, and FIG. 3 is a side view thereof. 6... Heat exchanger, 6... Fin plate, 7... Refrigerant pipe, 8... Light source,
9... Light receiving element, 1o... Frost.

Claims (1)

[Claims] A heat exchanger having a plurality of fin plates arranged one on top of the other at a predetermined interval, and located at a position a predetermined distance away from the edges of the plurality of fin plates and parallel to the direction in which the fin plates are arranged. A frost detection device comprising a light source and a light receiving element that receives light from the light source at a position, and light from the light source to the light receiving element is blocked by frost attached to the fin plate.