JPS6080740A - Detector for clogging of filter - Google Patents

Abstract

PURPOSE:To detect clogging of filter securely by arranging a light emitting element and photodetector both having flat faces facing oppositely to each other on one side of a filter so as to form an optical path parallel to the surface of a filter having many gas permeating pores. CONSTITUTION:An optical coupler 3 is provided directing toward the center of a filter 1 to the outside of a lower frame of the filter 1 supported by a frame body 2 so as to form an optical path parallel to the surface of the filter 1. A terminal 4 is provided to the frame body 2 and detection is executed by energizing through a connector provided to a part of a filter holder 5. Further, an optical coupler 3 is constituted of a light emitting element 6 and a photodetector 7 separated by a fixed distance and held facing oppositely. Both have physically almost flat optical surfaces and are housed in each case 13 with slits 9, 9 made of moulded bodies provided with convex lenses 8. By this constitution, secure detection of clogging of the filter is possible with high reproducibility.

Description

DETAILED DESCRIPTION OF THE INVENTION A) Field of Industrial Application The present invention relates to a filter clogging detector that can detect clogging with good reproducibility and reliability.

B) Prior Art In a conventional air conditioner with a 77-inch air conditioner as shown in FIG. 1, various filters 0υ are used in the intake holes. If this filter c3l) becomes clogged, the cooling/heating capacity will be reduced, or the power consumption will increase, and if the filter c3l is clogged, accidents such as fire may occur. Therefore, whether the user is asked to clean the filter regularly or whether it gets dirty varies depending on the actual conditions.The all-season type is always in use and gets in trouble when not in operation, so it is time for the user to clean the filter. I often forget. Some equipment that is constantly energized outside uses an energization timer to determine when it should be cleaned, but this is not sufficient because it has no direct relationship with the actual dirt on the filter. In addition, with methods that use electrodes for detecting electrical leakage, it is possible to detect dirt and scratches from the first time, but washing the electrodes creates the same conditions as electrical leakage, and cleaning with other methods does not allow for stains that have damaged the electrodes to be detected. Foreign objects in the dust become clogged, and the detection ability decreases each time from the second time onwards.

C) Purpose of the Invention The present invention improves the above-mentioned points and detects filter contamination and clogging with good reproducibility and reliability.

2) Structure of the Invention The present invention has an optical coupler having an optical path substantially parallel to the plane of the filter.The present invention will be described in detail below based on embodiments.

E) Embodiment FIG. 2 is a side view of a blind spot detector according to an embodiment of the present invention, and FIG. 3 is a perspective view of the main parts thereof. In the figure, (1) is a filter that is supported by a frame (2) and has a large number of ventilation holes, and is installed in the intake holes of air conditioners and the like. (3) is an optical coupler arranged toward the center of the VC filter outside the lower frame of the filter (1), and is arranged so that its optical path is approximately parallel to the surface of the filter (1). The terminal (4) is provided on the frame (2), and when the filter (1) is set in an air conditioner or the like, it is energized through the connector provided on a part of the filter holder (5). Detected. Therefore, it is possible to simultaneously check whether the filter txt has been set normally.

This optical coupler (3) consists of a light-emitting element (6) and a light-receiving element (7) that are held facing each other at a certain distance apart, for example, 5P
I204/I214 (both product names, Sanyo Electric). The pixel element is a molded body having a convex lens (8),
Case with slit +97 [91 (Although it is stored in [3, Surin]) (91F91 is the light emitting element (6)
It is filled with black resin σ-9, etc., which is transparent to the emitted light (for example: 90 onm infrared light), and its optical surface is flush with the case (13, that is, physically approximately flat and optically It has a condensing structure with a convex lens (8) and a slit [93f9J.

Generally, filters (11) are more likely to be contaminated in areas where there is a large amount of air from the fan, and therefore the center is more likely to be contaminated than the ends, but if the position and size of the intake holes are incorrectly designed, the difference will not be large. Therefore, as described below, there is a margin in the amount of light received (output) by the optical coupler (3), so even if the optical coupler (3) is located at the end of the filter (1),
If it is open facing the center, there will be no problem with detection. Furthermore, since the optical coupler (3) is small even including its optical path, it is easy to handle, and the emission wavelength can be infrared, which can be exposed to external light.

The mutual spacing between the light emitting element (6) and the light receiving element (7) of the optical coupler (3), that is, the optical path length, is 4 to 20 ff.
Since there are 3 mag.
It is. This is longer than the vent hole of the filter (13), but considering the reproducibility described later, it is preferable that the vent hole has an effective optical path length of 24 or less.Also, the optical path does not intersect with the filter, but is sufficiently close (the filter surface (The distance between the lens and the optical axis is preferably within 1-1), so there is no problem in detecting the amount of dust.

Figure 4 shows a filter (t,b) using a filter with a ventilation hole of 1 yus1 and an effective optical path length of 5, and the filter (
1) and optical coupler (3) as a function of the passage of time.
This shows the output of the light-receiving element (7) of the filter (1), which is visually determined to be the amount of accumulated dust that is obstructing ventilation (the eyes of the filter (1) are almost covered with white dust at 9:00). The amount of received light begins to saturate before it reaches the visual limit (hereinafter referred to as the amount of light that can be visually detected). Therefore, when the airflow rate starts to decrease ((:/), it is better to notify the filter (11) rather than prompting it to be cleaned, but this is due to a change in the amount of light received, so there is a margin. Since there is a margin in the notification detection level (design value) for the amount, it is easy to design the airflow amount by considering the distribution of the ventilation amount depending on the fan conditions and the variation in the characteristics of the optical coupler (3).

In the above example, the most important factor to improve reproducibility, that is, to notify you of filter contamination many times before it becomes noticeable, is to ensure that the dust in the effective optical path is removed when cleaning the filter (1). It is to be removed. For this reason, although the optical coupler (3) has a substantially U-shape, it may be made into a shape that is easy to clean, such as by making only the outer shape into a V-shape. However, as described above, if all the outer surfaces of the optical coupler (3) are physically flat, it is unlikely that dust will remain in the effective optical path during cleaning. Rather, it is necessary to clean the clogged filter 111 on the back side of the case lI3 of the optical coupler (3). Although it does not affect the detection, it feels unclean, so the filter 111 is also used to fix the optical coupler (3). It is preferable to partially inject resin from the back side of (1) to close the ventilation hole and also fill the gap between the optical coupler (3) and the filter.

F) Effects of the Invention As described above, the present invention comprises a filter having a large number of ventilation holes, and a light emitting element and a light receiving element arranged oppositely on one side of the filter so as to form an optical path substantially parallel to the surface of the filter. Since the filter is equipped with a blockage detector, blockages can be reliably detected and the reproducibility is good.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an air-conditioning/heating machine, FIG. 2 is a side view of a filter blind detector according to an embodiment of the present invention, FIG. 6 is a perspective view of the main part thereof, and FIG. 4 is a characteristic diagram thereof. (11... Filter, (2)... Frame, (3)...
・Optical coupler, (4j... terminal, (5)... filter holder, (6)... light emitting element, [7)... light receiving element, (8)... convex lens, f9Jt9 doors/slit,
13...Case, 1 old...black resin.

Claims (1)

[Claims] 1) A filter having a large number of ventilation holes, and a light-emitting element and a light-receiving element arranged oppositely on one side of the filter so that an optical path is substantially parallel to the surface of the filter. Features a filter clogging detector. 2) The patent Ruta's blind eye detector, characterized in that the length of the optical path is longer than the eye size of the ventilation hole and sufficiently shorter than the filter size. 5) The filter blind detector according to claim 1, wherein the optical surfaces of the light emitting element and the light receiving element are physically substantially flat.