JPH0696375A - Heat sensor - Google Patents

Abstract

PURPOSE:To reduce the cost of the heat sensor by integrating a heat collecting and sensing function part and making a case frame simple. CONSTITUTION:An integrated circuit 1a where a heat sensing part and a judging circuit are formed is mounted on a heat collection plate 1 made of aluminum, copper, or ceramic to integrate the heat collecting and sending function part, the heat collection plate 1 is coupled with the embedding part 2a of a sensing frame 2 to constitute a single-chamber frame, and the integrated circuit 1a is hermetically protected in the single-chamber frame. Then a bottom plate 3 is fixed to the case frame 2 across studs 3a and metal fittings 4 of electric terminals are fitted and fixed to the projection ends of the studs 3 with nuts 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat detector, and more particularly to an improvement of a heat collecting / heat sensitive function portion which simplifies a case frame and enables cost reduction.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 1-259494 shown in FIG.
In order to improve the assembling workability of the heat sensor having a complicated structure, the rubber packing corresponding to the above-mentioned inner cover is replaced with the inner cover 20 of the molded product, while the semiconductor thermosensitive element 30a is first attached to the printed circuit board. After being soldered to 30, the semiconductor heat sensitive element is projected outward from the central hole 20a of the middle cover 20 so that the printed circuit board 30 is housed between the middle cover 20 and the base 40. Therefore, as the frame structure, a quadruple structure in which a printed board is added to the three divisions of the cover, the inner cover and the base is used as it is.

FIG. 3 shows a conventional example in which a semiconductor thermosensitive element 30a is housed in a titanium protective tube 30b in order to enhance protection and a titanium heat collecting plate 30c is attached to the tip of the protective tube 30b. In this example, which is used in a laboratory or a hot spring bath where corrosive gas exists, the lower end of the titanium protective tube 30b is welded to the central protruding portion 41a of the case frame 41 so that the inside of the case frame 41 is secured. Airtight protection. Therefore, the tip ring portion 10a of the cover 10 is divided and the case frame 41 is
The cover 10 and the cover 10 are integrally molded. Cover the protection tube 30b.
After being fixed by welding to the case frame 41 inside 10, the tip ring portion 10a is joined to the tip of the cover 10.

By assembling the semiconductor thermosensitive element 30a to the printed circuit board 30 first by soldering, the assemblability in this respect was improved, but since the semiconductor thermal detecting element was projected into the cover to form the functional portion, Divided hippo-10, medium hippo-2
0, the base 40 requires a mold for molding, respectively, and the assembly of four parts in which the printed circuit board 30 is added to these three parts still remains. Moreover, in order to hermetically protect the electrical components of the printed circuit board 30, the protective tube 30b and the heat collecting plate 3 are provided.
0c is required, and the assemblability in this case is even worse.
Moreover, since it is a circuit that combines a large number of electronic components, each component becomes thermally separated and a temperature difference occurs between the components, and a temperature compensation circuit for removing this is required for each. , The actual electronic circuit has become quite complicated.

[0005]

In order to raise the technical level of the heat detector and reduce the cost for its widespread use, the semiconductor heat detecting element is projected into the cover or inside a protective tube with a heat collecting plate. While developing electronic technology that promotes the integration of heat-sensitive / protective function parts by eliminating the need to project and store them in multiple parts, multiple molds and multiple parts that are the primary cause of high cost and the mechanical structure that requires assembly of these It is necessary to eliminate division / multiplicity.

[0006]

Means for Solving the Problems A heat detecting element and a comparing portion for comparing and outputting the output from the heat detecting element are formed in an integrated circuit, and the integrated circuit is mounted on a heat collecting plate made of aluminum, copper, ceramics or the like. With the built-in configuration, the heat collecting and heat-sensitive functions are integrated, which simplifies the structure of the case frame.

[0007] It was confirmed by trial manufacture that a heat detecting element was directly mounted on a heat collecting plate made of aluminum, copper, ceramic or the like by soldering or the like to satisfy the fire alarm issuing operation condition. Electronic technology, which was delayed in the field of heat detectors, could not combine the heat collecting / sensing function and the electronic circuit for taking it out, but due to this success, the case frame that relied on the split / multiple structure The structure can be leapt to a single room / single weight structure.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a single-chamber thin type heat sensor.
A heat detecting element and a comparing section for comparing and outputting the output from the detecting element are formed in the integrated circuit 1a. The integrated circuit 1a having a heat sensing unit and an amplifying circuit is mounted on the heat collecting plate 1. In addition, the auxiliary circuit electronic component 1b required to match the alarm system is also mounted on the heat collecting plate 1. The heat collecting plate 1 is preferably made of aluminum, copper or ceramic, and other similar materials having good heat conductivity are used. The shape may be any of a disc, a rectangular plate and a polygonal plate, and the disc is preferable from the viewpoint of directionality and the like.

As the heat sensing portion of the integrated circuit 1a, a diode having a temperature-electric characteristic in which a voltage changes linearly with temperature is used in this example. In addition, a transistor having a linear temperature-electric characteristic in the temperature detection range can be used, and a thermistor can also be used. The heat released from the monitoring area is received by the heat collecting plate 1, compared with the alarm temperature determined by the integrated circuit 1a, and when the alarm temperature is reached, the heat is output from the amplifier circuit. Since each circuit element part in the integrated circuit has the same temperature environment, it is possible to stabilize the output characteristics without adding a temperature compensation circuit to each part.
The structure of the integrated circuit is as simple as possible.

The result of the test conducted on the aluminum, copper and ceramics of the heat collecting plate 1 is that the thermal conductivity (cal / cmS ° C.) is about 0.05.
It is possible to give a margin to the setting conditions when issuing a notification with the alumina ceramics of, and with the general ceramics of 0.48, copper of 0.94, and aluminum of 0.54. The dish-shaped case frame 2 is manufactured by a mold having a simple shape in which the fitting portion 2a of the heat collecting plate 1 is hollowed out, and the heat collecting plate 1 is welded and fixed to the fitting portion 2a. The flat bottom plate 3 is easily manufactured by injection molding or punching from a plate material.

The assembly is carried out by collecting the heat collecting plate 1 on which the integrated circuit 1a is mounted.
Are fitted in the fitting portion 2a of the case frame 2, and then the joined portion is welded by high-frequency treatment or the like. The heat collecting plate 1 and the case frame 2 form a completely sealed single chamber. Then, the bottom plate 3 is fixed to the case frame 2 with the studs 3a interposed therebetween. It is simple and preferable to connect an electric circuit to the outside by passing an electric wire through the hollow portion of the stud 3a. The fitting 3 of the electric terminal is attached to the protruding end of the stud 3a with the nut 3b and fixed. Fitting 4
Can be installed and electrically connected at the same time by rotating the indoor wiring with respect to the pair of fittings. Single room
The present invention having a single-layer structure has an overall thickness of 1.5 cm,
It is possible to make a small and thin thermal sensor with a width of 10 cm square.

[0012]

From the viewpoint of material technology, it is ideal for the heat sensor to have a small number of molds, a small number of parts, and a thin shape that has no protruding portions and is not damaged by collision. The conventional heat detector technology, which had to be compelled, must be renewed. Regarding this main point, the new electronic technology of the present invention in which the heat sensing unit and the judgment / amplification circuit are configured in one integrated circuit and the heat collecting / heat sensitive function unit is integrated by mounting this on the heat collecting plate is The heat sensor has a streamlined single-layer / single-chamber structure, has an excellent external shape, and inevitably has a sealing protection function that does not deteriorate even when used in any atmosphere. Elimination of waste of materials such as electronics and plastics and elimination of various molds also drastically reduces the assembly cost and opens up the important cost reduction path for the further popularization of heat detectors. Was able to fit.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view of a heat detector according to the present invention.

FIG. 2 is an exploded perspective view of a conventional heat sensor.

FIG. 3 is an exploded partial perspective sectional view of another conventional heat sensor.

[Explanation of symbols]

 1 Heat Collection Plate 1a Integrated Circuit 1b Electronic Component 2 Case Frame 2a Fitting Part 3 Bottom Plate 4 Fitting Metal Fitting 10 Cover 10a Ring Part 20 Middle Cover 30 Printed Circuit Board 30a Semiconductor Thermal Element 30b Protective Tube 30c Heat Collection Plate 40 base 41 case frame

Claims (1)

[Claims] 1. A heat sensor comprising a detection element for detecting heat generated by a fire through a heat collecting plate, wherein at least the detection element and a comparison section for comparing and outputting an output from the detection element are integrated circuits. A heat detector formed inside the heat collecting plate, the integrated circuit being mounted on the heat collecting plate.