JPH05266376A - Heat sensor - Google Patents

Abstract

PURPOSE:To attain comprehensive cost reduction so as to popularize a heat sensor still more by developing an integrated circuit provided with a self- diagnostic function by developing further the summarized electronic techique of a heat collecting/heat sensing function part capable of simplifying even the case frame of the heat sensor hating been of multipartitioned and multiplex construction. CONSTITUTION:The integrated circuit 3 in which circuit elements 3c are arranged around a heat detecting element 3A to be used also as a heat generating element is provided with a means to flow a constant current and the means to flow an overcurrent at the time of inspection. After the heat detecting element 3A is heated by itself by the overcurrent at the time of the operation of the inspecting means, the heat detecting element 3A receiving the constant current issues information by its held heat, and diagnoses itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a heat sensor having a self-diagnosis function, and more particularly to an electronic technology for integrating a self-diagnosis function and a heat collecting / heat-sensing function, and at the same time, the integration is complicated. And the improvement of the frame structure for simplifying the case frame.

[0002]

2. Description of the Related Art In Japanese Utility Model Laid-Open No. 63-118692 shown in FIG. 7, a self-diagnosis means that does not require a separate device is provided for the purpose of checking the presence or absence of deterioration of the function of the heat sensor and checking the heat detection operation normally. It was installed inside the vessel. The structure is such that a projecting frame 6 is projected on the front surface of the sensor case frame 60.
1 is covered with a heat-sensitive fin 50, a temperature-sensitive sensor 70 and a common ring heater 80 are attached along the inner side of the heat-sensitive fin, and two kinds of heat discoloration tapes for high temperature and low temperature for visual check are attached. 81 and 82 are attached to the heat-sensitive fin 50. A switch-type energizing means 90 is attached to the ring heater 80 in order to generate heat during inspection.

Since there is no technical pursuit to reduce the cost of the heat detector, the cost of these additional means 80, 81, 82, 90 provided for energizing at the time of self-diagnosis and inspection increases as it is. As a result of neglecting to pursue cost reduction technology despite the improvement accompanied by the increase in parts, against the cost that is greatly affected by the size, size, difficulty, etc. of the number of molds, the number of assemblies, the amount of materials, the number of parts, storage, etc. Although the self-diagnosis means is built in, the cost becomes high and it is not always useful for the further popularization of the heat detector.

The common ring heater 80 is a print pattern.
Since it is considerably larger than the required current or voltage of the semiconductor element forming the circuit, it is not suitable as a means for improving the function, and there is no content to upgrade the electronic technology. Also,
Since the conventional structure of the heat detector was followed as it is to add the means 80 and 90 necessary for the self-diagnosis function, the improvement of the material technology, the electronic technology and the operation design technology of the heat sensor has not been started yet. The skill level of is virtually unchanged.

[0005]

Recognizing that the electronic technology in the heat sensor will be a technology base for guiding the case frame as thin as possible, a printing / printing device more suitable for heat sensing will be provided. While pursuing the structure of the pattern semiconductor device circuit and incorporating the requirements of the self-diagnosis function in the circuit structure, the technical level of the electronic circuit of the sensor is raised while the electronic circuit is hermetically supported by a simple case frame. We will also improve the mechanical structure of the heat detector, improve the productivity by adding the self-diagnosis function, and further improve the design technology level of the heat detector for further cost reduction.

[0006]

A heating element that generates heat when an electric current is passed is provided in the vicinity of a heat detecting element used in a heat sensor, and these heat generating element and heat detecting element are formed in an integrated circuit. The output of the heat detecting element can be diagnosed by causing the heat to generate.

Further, a semiconductor element that generates heat by passing an overcurrent is used as a heat detecting element, the heating element is formed in an integrated circuit, and means for supplying a constant current to the heating element and a current exceeding the constant current during inspection are provided. And a self-diagnosis means for causing the heat detecting element to self-heat by the operation of the checking means, and then the heat detecting element which receives a constant current outputs a required output by its own heat.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 6, when a voltage change with respect to a temperature change is traced for a diode 15 of 0.6 V connected to a constant current circuit 14, dV / dT = -2 mV / ° C.
Is obtained (FIG. 5). This linear change can be used as a heat sensing output and also as a heat sensor in terms of accuracy. When a similar electronic device is examined by using this example, a relatively large number of temperature-electric characteristics in which a thermal change is stably repeated can be recognized, and therefore, it is formed in an integrated circuit depending on conditions. When the temperature-electric characteristic value showing the repeated stability is small, it is formed in an integrated circuit in combination with an amplifier circuit.

As shown in FIG. 4, the contents of the integrated circuit depend on what kind of fire detection / warning system the heat detector is used for. For example, for the output of the heat detection unit 8 having a heat detection element, Then, the judging section 7 of the comparison circuit for comparing the reference value determined corresponding to the monitored temperature with this output, the amplifying section 6 for amplifying the output of this judging section 7 to a required level, and energizing these circuit sections. Together with the control unit 5 for checking the level of the amplification unit 6 and sending a signal to the system, four circuit units are formed as one integrated circuit. By using one IC circuit, a simple circuit configuration in which the thermal influence on the heat detection unit 8-judgment unit 7-amplification unit 6-control unit 5 is unitarily determined. This point is important. That is,
In the conventional technology of combining these four circuit parts with independent parts,
Since the temperature correction circuit is added to each part to eliminate the difference in temperature influence, and the circuit has a large accommodation space, the IC circuit fundamentally upgrades the conventional electronic technology. The case frame containing the IC circuit is manufactured in a simple shape according to this size. In order to allow the heat detection part of the IC circuit to catch the heat released from the monitoring area, the IC circuit, which has become smaller and has a much smaller thermal capacity, is carried on the heat collecting plate 1 made of aluminum, copper, ceramic or the like (FIG. 1). ).

FIG. 2 shows a circuit element arrangement pattern of the heat detecting section 8-determining section 7-amplifying section 6-control section 5 which is formed in one integrated circuit 3. The heat detecting element 3a of the heat detecting unit 8 is arranged at substantially the center of the integrated circuit 3, the heat generating element 3b is arranged around it, and the required circuit element 3c is arranged around it. A representative example of the heating element 3b is shown in FIG. It is easy to form the transistor 11, the diode 12, the resistor 13, and the heating element 17 in the integrated circuit 3. The heating element 17 forms the electric passage 17b having a small area so as to narrow the area with respect to the large area 17a of the electric conductor having a large area, and can energize the electric surface 17a to generate heat as designed.

FIG. 3 shows another circuit element arrangement pattern.
The heat detecting element 3A also serves as a heat generating element. Therefore, the heat generating element 3b of FIG. 2 is not provided, and only the required circuit element 3c is provided around the heat detecting element 3A. FIG. 6 shows an example of this heat detecting element 3A. In this example, a diode 15 is connected to the constant current circuit 14, and a voltage change due to the temperature of the diode 15 is connected in parallel to the input side of the diode 15. The load 16 is taken out.

The control circuit 5 shown in FIG.
The heating circuit 10 of the heating element 3b is connected via the. When the inspection circuit 9 is turned on, the heating element 3 of the heating circuit 10 is turned on.
When b is heated to a predetermined temperature, the heat detecting element 3a surrounded by the heat generating element 3b performs an output operation at that temperature and self-diagnoses. Further, the heat detecting portion 8 using the heat detecting element 3A which also functions as a heat generating element turns off the check circuit 9 after a relatively large current flows due to the check circuit 9 being turned on to generate heat to a predetermined temperature.
Causes a normal constant current to flow. The heat detecting element 3A that has generated heat due to overcurrent receives a normal constant current after that, performs an output operation, and performs self-diagnosis. In the case of a system having a large number of heat detectors, a constant current and an overcurrent are supplied from the control unit 5 without using the inspection circuit 9, and for example, a self-diagnosis signal is supplied from the center by time sharing. If the heat is generated in the first half of the signal, the operation is output in the second half, and this output is received, the self-diagnosis for each maintenance cycle can be accurately performed.

The test results for aluminum, copper and ceramic of the heat collecting plate 1 carrying the integrated circuit 3 shown in FIG.
It is possible to give a margin to the setting conditions for the alumina ceramic with a thermal conductivity (cal / cmS ° C) of about 0.05 and the general ceramics of 0.48, copper of 0.94, and aluminum of 0.54. The heat collecting plate 1 is fixed to the case frame 2 by welding, the bottom plate 4 is joined via the stud 4a, and the connector metal fitting 4b for electrical connection is attached to the protruding end of the stud 4a to integrate with the external electric circuit. Connect to the circuit. In addition, the individual required circuit element chips 3d necessary for connection with various systems may be used in combination with the integrated circuit 3. The present invention, which has a single-chamber / single-weight structure, makes it possible to make a small and thin thermal sensor having an overall thickness of 1.5 cm and a width of 10 cm square.

[0014]

From the viewpoint of material technology, the ideal heat sensor is a thin type which can be manufactured with a small number of molds and a small number of parts and has no protruding portion and no collision damage portion. The conventional heat detector technology, which had to be bulky and multi-divided / multi-structured, must be renewed. Regarding this main point, the new electronic technology of the present invention in which the heat detection unit and the judgment / amplification unit are configured in an integrated circuit and the heat collection / heat sensitive function unit is integrated by mounting the heat detection unit on the heat collection plate is a case frame The heat sensor has a new structure that is rationalized into a single-weight, single-chamber structure all at once, and inevitably has a sealed protection function that does not deteriorate even if used in any atmosphere. Cost reduction by eliminating waste of materials and elimination of various types of molds for electronics, plastics, etc. will also significantly reduce the assembly cost, and the cost reduction method indispensable for the further popularization of heat detectors. The present invention, which has an important result of opening up the heat sensor and has a self-diagnosis function without causing a high cost, contributes to further popularization of the heat sensor.

[Brief description of drawings]

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

FIG. 2 is a circuit element arrangement pattern of an integrated circuit according to the present invention.
FIG.

FIG. 3 is an explanatory view illustrating another circuit element arrangement pattern.

FIG. 4 is an explanatory diagram showing a configuration example of an integrated circuit.

FIG. 5 is a graph showing temperature-electrical characteristics of the diode.

FIG. 6 is a circuit element diagram showing four examples of heat generating elements and one example of heat detecting elements.

FIG. 7 is a sectional view of a conventional heat sensor with a self-diagnosis function.

[Explanation of symbols]

 1 Heat Collection Plate 2 Case Frame 3 Integrated Circuit 3a Heat Detection Element 3b Heat Generation Element 3c Circuit Element 3A Heat Generation Element Combined Heat Detection Element 4 Bottom Plate 5 Control Section 6 Amplification Section 7 Judgment Section 8 Heat Detection Section 9 Inspection Circuit 10 Heat Generation Circuit 15 Diode 17 Heating element 50 Thermal fin 61 Protruding frame 70 Temperature sensor-80 Ring heater 81 Thermal discoloration tape 82 Thermal discoloration tape 90 Switch type energizing means

Claims (2)

[Claims] 1. A heat sensor including a detection element for detecting heat generated by a fire, wherein a heating element that generates heat by passing an electric current is provided in the vicinity of the detection element, and at least the heating element and the detection element are integrated. A heat sensor, which is formed in a circuit and causes the heating element to generate heat to diagnose the detection element. 2. A heat sensor comprising a detection element for detecting heat generated by a fire, wherein the detection element is an element that generates heat by passing an overcurrent, and at least the heating element is formed in an integrated circuit. A means for supplying a constant current to the heating element and an inspection means for supplying a current exceeding the constant current at the time of inspection, the heating element is self-heated when the inspection means is activated, and self-heated by the retained heat after the operation of the inspection means. A heat detector characterized by making a diagnosis.