JPH028071Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of an automatic door switch that always operates normally even in extremely cold regions such as snowy regions.

Conventionally, when opening and closing an automatic door using a light switch using visible light or infrared rays, for example, as shown in FIG. 1A, light L from a light emitting section 1 is received by an opposing light emitting section 2. It is detected that the light L is blocked by a passerby 3, and the automatic door is opened and closed depending on whether the light L is received or blocked. In another example, as shown in FIG. This reflected light is detected by the light receiving section 2, and in this case as well, the door is automatically opened and closed when the light emitting section 2 detects that the light L is blocked by a passerby.

In the case of Japanese architecture, the door 12 is installed on the inside (inside the house) of the entrance and exit pillars 10 and 11, as shown in Figure 2, and the light emitting part for the automatic door is installed inside the house. 13 and a light emitting section 14 are provided outside the pillars 10 and 11 (outside the house), respectively.

Therefore, the light emitting section 13 and the light emitting section 14 are directly affected by the outside air environment, and in extremely cold regions, snow falls or falling rain turns into ice, causing snow to form on the surface of the light emitting section 14 or the light emitting section 13. The problem is that the door 12 cannot be opened and closed automatically and reliably at all times because the light transmitting part is blocked by the adhesion of water and ice.

Therefore, the object of this invention is to provide an automatic door switch structure using a light switch that does not have the above-mentioned drawbacks.

This idea will be explained below.

This invention relates to the structure of an automatic door switch for use in extremely cold regions.A heating element (e.g., a positive temperature coefficient thermistor; barium titanate) is fixed to a thermally conductive casing with a built-in light switch for automatic doors using a highly thermally conductive resin. (based on semiconductors) is buried. That is, FIG. 3 shows an assembly diagram of the automatic door switch of this invention, in which an elliptical hole 21 is bored in the upper surface of a rectangular parallelepiped-shaped housing 20 made of a thermally conductive material such as aluminum or brass. cage, housing 20
A circular hole 22 is bored in the front side of the holder. A sensor (for example, a photodiode) 30 is inserted into the housing 20 and is engaged with a decorative metal 40, and a pedestal 41 of the decorative metal 40 is inserted into the housing 2.
It is designed to engage with the hole 22 of 0. Also,
A disc-shaped projection 42 provided on the top surface of the decorative metal 40 is adapted to be screwed into a hole 51 provided in the center of the switch mounting plate 50, and the mounting holes 52 and 53 are used to attach the automatic door switch. It is designed to be installed at a desired location on the pillar near the door. Furthermore, a POSISTOR 60 as a heating element is buried through the hole 21, and this PTC thermistor 60 is fixed to the inner wall of the housing 20 using a high heat conductive resin such as epoxy resin. Terminals 61 and 62 of positive temperature coefficient thermistor 60
A heating voltage is applied to the
The voltage applied to the sensor 30 and the positive temperature coefficient thermistor 60 is supplied from the outside via lead wires 23 and 24.

Figure 4 shows a cross section of the internal structure of the automatic door switch of this invention, and shows the positive temperature coefficient thermistor 6.
0 has a terminal 61 in the hole 21 with high heat conductive resin 63.
and 62 are fixed so as to be taken out. The light receiving element 31 of the sensor 30 is included in the cylindrical portion 43 of the decorative metal 40, and receives light from the light emitting portion through a light receiving hole 44 formed in the center of the decorative metal 40. I'm starting to do that. Furthermore, the protrusion 4 of the decorative metal 40
2 is provided with a groove 45 that passes through the top and bottom,
It is designed to promote drainage effects.

In an automatic door switch having such a structure, for example, as shown in FIG. An automatic door switch is being installed.

In such a structure and installation, the positive temperature coefficient thermistor 60 embedded in the high heat conductive resin 63 is
It is driven with a constant voltage via terminals 61 and 62. Here, as shown in FIG. 6, the resistance R of the positive characteristic thermistor 60 changes rapidly with the temperature _T0 as a boundary, so if the temperature is lower than the temperature _T0 , the resistance R changes rapidly due to the low resistance. The positive temperature coefficient thermistor 60 is heated, and the heat is transferred to the high heat conductive resin 63 and the housing 2.
0 and is conducted to the decorative metal 40. Therefore,
Even if the automatic door switch is installed in a cold region and ice or snow adheres to the surface of the decorative metal 40 and blocks light, it will be melted by the conducted heat, and the melted water droplets will form the grooves 45. The water is then drained to the outside. In this way, there is no chance of ice or snow accumulating on the automatic door switch and causing the automatic door to malfunction. Note that the temperature of the positive characteristic thermistor 60 is the temperature
If T exceeds ₀ , the positive characteristic thermistor 6
Since the resistance R at 0 suddenly increases, the flowing current decreases, causing the positive temperature coefficient thermistor 60
The exothermic temperature will also drop rapidly. Therefore, the PTC thermistor 60 is always heated at a constant temperature, and the sensor 30 and the like will not be overheated and damaged.

In the above embodiment, the protrusion 42 of the decorative metal 40 is provided with a drainage groove 45, but as shown in FIG. 7, the surface of the protrusion 42 may be tapered to dissolve water droplets. . Also, a housing 20, a sensor 30, a decorative metal 40, a switch mounting plate 5
The structure and shape of the PTC thermistor 60 can be changed arbitrarily, and the point is that the heat generated by the PTC thermistor 60 is conducted through the housing 20, and snow, ice, etc. adhering to the holes 44 of the decorative metal 40 can be melted and drained. It's fine if it's something like that. Furthermore, although the structure of the light receiving section has been described above, a similar effect can be obtained by embedding a positive temperature coefficient thermistor in the light emitting section.

On the other hand, as shown in FIG. 8, two light emitting parts 81 and 82 are provided on one pillar near the automatic door, and two light receiving parts 83 and 84 are provided on the other pillar.
3 and 84 both receive light from the light emitting parts 81 and 82, even if one of the light emitting parts or the light receiving part becomes blocked by snow, ice, etc. This can prevent automatic doors from malfunctioning. In this case, the distance d between the light receiving sections 83 and 84 must be such that it does not affect passersby.

[Brief explanation of the drawing]

Figures 1A and B are diagrams showing the schematic configuration of a conventional automatic door switch using light, Figure 2 is a diagram to explain how the light emitting part and light receiving part are installed on the door, and Figure 3 is a diagram showing the automatic door switch of this invention. An assembly diagram showing how the door switch is assembled, FIG. 4 is a partial sectional view showing the schematic structure of the automatic door switch of this invention, and FIG. 5 is a diagram showing how this invention is installed on a pillar.
Figure 6 is a characteristic diagram of the heating element used in this invention, Figure 7
The figure is a perspective view showing another structural example of the decorative metal used in this invention, and FIG. 8 is a diagram showing an example of application of this invention. 1, 3... Light emitting section, 2, 14... Light receiving section, 1
0,11,70...Column, 20...Casing, 30...
Sensor, 40... Decorative metal, 44... Light receiving hole, 50... Switch mounting plate, 60... Positive temperature coefficient thermistor, 63... High thermal conductive resin, 81, 82
... Light emitting section, 83, 84 ... Light receiving section.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An automatic door switch for use in extremely cold regions, characterized in that a heating element fixed with high thermal conductive resin is embedded in a thermally conductive casing containing a built-in light switch for automatic doors. 2. The automatic door switch for extremely cold regions according to claim 1, wherein the heating element is composed of a positive temperature coefficient thermistor.