JPH03246429A - Distribution type heat sensitive element - Google Patents

Abstract

PURPOSE:To facilitate work and to reduce the cost of the work by placing heat sensitive wires on a base plate having a good heat insulating characteristic in order to eliminate the influence of a difference in the material quality of a ceiling and wall and a difference in the degree of adhesion, thereby detecting room temp. evenly in average. CONSTITUTION:Metallic wires are previously mounted long as the heat sensitive wires 2 along the ceiling surface. The temp. can be calculated when the resistance thereof is measured. The relation between the resistance and the temp. is determined if the diameter and length of the electric wires and the kind of the metal are known and, therefore, the electric wires act as the distribution type heat sensitive element 1. The easier work is assured by previously attaching a tacky adhesive material 5 to the rear of the base plate 3, preventing the tacky adhesion by means of a film 6 prior to the work, peeling the film at the time of the work and sticking the element to the ceiling surface. Since the heat sensitive wire 2 and the ceiling surface are not brought into direct contact with each other in such a manner, there is no influence of the difference in the material quality of the ceiling.

Description

[Detailed description of the invention] (a) Industrial application field The present invention is a distributed heat-sensitive element that detects room temperature not from a point but from a wide area, and in which a portion of the sensor is distributed, and is suitable for use in fire detectors and air conditioning. Regarding what is used.

(B) Prior Art Conventional heat-sensitive elements that detect room temperature at a single point, such as sensors for air conditioning, sometimes show values that are far from the average value of room temperature. In addition, some distributed fire detectors utilize the expansion of air inside copper pipes or have thermocouples lined up in a line, but these are more sensitive than spot type fire detectors because they detect differences in the location of a fire at room temperature. Although copper pipes had the advantage of being less sensitive, installation work was difficult, and even after installation, the hollow pipes were soaked by mechanical shock, rendering them useless.

Thermocouples were also difficult to manufacture, and although both were so-called differential fire detectors, even if the rate of temperature rise was known, the temperature (absolute value)
For example, information such as 21°C could not be obtained. In addition, variations in sensitivity occurred due to differences in heat conduction with the ceiling due to differences in the degree of adhesion to the ceiling surface due to the material of the ceiling and construction method.

(8) Problems to be solved by the invention By taking advantage of the characteristics of the distributed heat-sensitive element, it captures the room temperature uniformly and evenly, is easy to install, has little change in sensitivity depending on the construction method or the material of the ceiling, and has no malfunctions. To provide a heat-sensitive element that is difficult to heat.

(:)Means for solving the problemUsing a metal wire with a uniform content instead of a hollow pipe for easy manufacture. To reduce radio wave interference 2
Use insulated wires twisted together.

The heat-sensitive wire is placed on a substrate with good thermal insulation to eliminate the effects of differences in the material and degree of adhesion of the ceiling and walls.

Add adhesive to the back of the board to make construction easier.

Pure metal wire is used to obtain a high temperature coefficient of resistance. Add a length scale to make it easier to calculate the resistance value.

(Book) Functional metal wires generally increase their resistance as the temperature increases. This feature is especially great for pure metals. Therefore, by attaching a long metal wire as a heat-sensitive wire along the ceiling surface and measuring its resistance, the temperature can be calculated.

If the diameter and length of the wire and the type of metal are known, the relationship between resistance and temperature is determined, so it functions as a distributed heat-sensitive element.

Construction will be easier if you apply adhesive material to the back of the board in advance, use a film to prevent it from sticking before construction, and then peel off the film and stick it to the ceiling surface when construction is done.

Since the heat-sensitive wire does not come into direct contact with the ceiling surface due to the thermal insulation element, there is no effect due to differences in the material of the ceiling.

Kube) Example FIG. 1 is a sectional view of the embodiment, and FIG. 2 is a side view.

In Figure 1, 1 is a heat-sensitive element, 2 is a heat-sensitive wire, and 3 is a substrate.

4 is an adhesive material, 5 is an adhesive material, and 6 is a non-adhesive film pasted on the adhesive material.

In FIG. 2, numeral 7 is a mark indicating the length of the heat-sensitive element l attached on the substrate 3.

Metals with high purity have a high temperature coefficient of resistance.

For example, pure iron is 6.6 X 10-”/”C, aluminum is 4.2X 10-”/”C, and copper is 4.3
x 10-'/'C, = Nogal is 6°7XIO-"
/”It is C.

Among these, nickel wire is the heat-sensitive wire 2 because it has high resistivity, is not very expensive, and has excellent corrosion resistance.
shall be. Use nickel wire with an insulating coating.

If it is spread widely on the ceiling surface, rust noise etc. will increase, so
/N is used by twisting two wires together.

This heat-sensitive wire 2 is fixed with an adhesive 4 onto a substrate 3 made of a material with good thermal insulation properties.

Various thermal insulators can be used as the material for this board 3, but it is easy to bend because it may be bent at right angles during construction.
Use something that is hard to break. For example, something like urethane foam.

This board is about 1 to 5 mm thick and 3 to 5 mm wide.
Make it Ion m.

If the substrate 3 is thermoplastic, the heat-sensitive wire 2 and the substrate 3 may be attached by slightly embedding the heat wire 2 therein using heat, and omitting the adhesive 4.

A mark 7 indicating the length of the heat-sensitive wire is attached to the side or bottom surface of the substrate 3.

In the example shown in FIG. 2, five landmarks from 10.1 m to io and 5 m are placed vertically on the center line.

This value may be the length of one heat-sensitive wire 2 instead of the total length of the two heat-sensitive wires 2, or it may be the value of two wires, but the former is more convenient for construction designers to prepare layout drawings. It would be very convenient.

This value of mark 7 is repeated every 300m. This is because the total length is usually from several tens of meters to over 100 meters, so if the repetition is too short, it will be difficult to calculate the total length.

Although one end of the sensing wire is not shown, it is attached to two terminals for resistance measurement, respectively.

The other ends are electrically joined together by soldering or the like to form a loop.

Now, the mark 7 of the heat sensitive wire 2 where it exits the resistance measurement terminal is 562
m, and the other end is 215.6 m, the total length is 215.6 - 56.2 = 159.4 m. Since the material and diameter of the heat-sensitive wire 2 are predetermined and manufactured at the factory, once the length is known, the resistance of the heat-sensitive wire 2 at a standard temperature can be calculated just by knowing the length.

For example, the resistance per unit of a 0.2 mm diameter nickel wire at 20°C is 1 m x 2 x 7.24 x 10-”Ω・m /
<tr x 0.0001 m'') = 4.61 Ω, where 7.24 x 10-'' Ω·m is the resistivity.

Therefore, the resistance value of the heat-sensitive wire 2 with a total length of 159.4 m at 20°C is 4.61 x 159.4 = 735 Ω.

Assuming that the current resistance value of the heat-sensitive wire 2 is 760Ω, 760-735=25Ω is the increase in resistance due to temperature rise. The temperature coefficient of resistance of nickel is 6.
Since it is 7X 10-”℃, the temperature increase is 25Ω/
(735Ω×6.7×10−”°C)=5.08°C.

That is, the temperature of the heat-sensitive wire 2 is 20°C+5.08°C=25.08°C. In this way, the average temperature of the heat-sensitive line 2 can be easily determined.

When applied as a distributed fire detector, the total length of the heat-sensitive wire 2 must be kept to the national standard so that it can be distinguished between cases where the entire heat-sensitive wire 2 is gradually heated by heating, etc. and cases where a portion of the heat-sensitive wire 2 suddenly rises in temperature due to a fire. It is being The method of distribution when pasting on the ceiling of a room is also specified in detail.

Attach adhesive material 5 to the bottom for attaching to the ceiling (
. A film 6 is attached on top of it to prevent it from sticking until construction work. During construction, this film 6 is peeled off and pasted on the ceiling just before construction begins.

FIG. 3 shows yet another invention.

In FIG. 3, 8 is a mechanically strong metal wire such as piano wire.

The heat-sensitive element 1 shown in Fig. 1 uses a mechanically weak metal wire such as pure nickel wire as the heat-sensitive wire 2, so it is easily bent when passing through a long, narrow hole such as when penetrating a wall. Construction is difficult.

The metal wire 8 is provided to increase the mechanical strength of the heat-sensitive element 1 and make it difficult to bend in such a case.

The metal wire 8 allows the heat-sensitive element 1 to maintain a straight line, thereby facilitating construction work such as when penetrating a wall.

As the metal wire 8, a material with high tensile strength and high elastic limit, such as piano wire, is suitable.

The metal wire 8 may be embedded within the substrate 3, or may be embedded within the substrate 3.
It may be connected to the outside of the top, side, bottom, etc.

(G) Effects of the Invention The heat-sensitive element of the present invention exhibits the following various effects compared to conventional ones.

Since the element itself is inexpensive and the construction is easy, the construction cost is low.

Because it measures the average room temperature, it is also suitable for air conditioning, and as a fire detector, there is less variation in sensitivity due to differences in the location of the fire compared to the spot type.

Maintenance is easy because the mechanism is durable.

The actual total length of the heat-sensitive wire can be easily calculated upon completion of construction.

There is little sensitivity change due to differences in thermal conductivity due to ceiling and wall materials.

There is also little change in sensitivity due to differences in the degree of contact with the ceiling surface.

The heat-sensitive element has good mechanical linearity and is easy to construct.

As described above, the present invention is very effective in practice.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a side view with a part thereof omitted, and FIG. 3 is a sectional view showing another embodiment of the invention. 1... Heat-sensitive element, 2... Heat-sensitive wire, 3... Substrate 4... Adhesive material, 5... Adhesive material. 7...Mark 8...Metal wire 6...Film

Claims (5)

[Claims] (1) A distributed heat-sensitive element comprising a heat-sensitive wire made by twisting two metal wires together and a substrate made of a thermally insulating material to which the heat-sensitive wire is fixed. (2) The distributed heat-sensitive element according to claim 1, wherein a layer of adhesive material is formed on the back surface of the substrate. (3) In the distributed heat-sensitive element according to claim 1 or 2,
A distributed heat-sensitive element, characterized in that the substrate is marked with a mark indicating the length of the heat-sensitive element. (4) The distributed heat-sensitive element according to claim 1, 2 or 3, wherein the heat-sensitive wire is formed of a pure nickel wire. (5) The distributed heat-sensitive element according to claim 1, 2 or 3, wherein a metal wire with high mechanical strength is attached to the outer surface or inside of the substrate.