JPH02176897A - Differential thermosensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a differential heat sensor, and more particularly to a differential heat sensor in which a chamber is joined to a mold body to form an inner chamber therebetween.

[Prior Art] This type of differential heat sensor has a mold body supporting a contact point through a spring plate, and this contact point is actuated by the displacement of a diaphragm that constitutes a heat-sensing chamber section to prevent a fire. It is designed to be sensed.

This chamber portion is attached to the mold body to form an inner chamber between the chamber portion and the mold body, as shown in FIG. 7 or 8 in the past.

In FIG. 7, an annular attachment groove 32 is formed in the peripheral edge of the mold body 31, and a joint part 34 on the peripheral edge of the chamber part 33 is inserted and bonded into this attachment groove 32 with an adhesive 35 to connect it to the mold body 31. A flow passage 3 is provided in the mold body 31 to form an inner chamber 36 therebetween and to adjust the air pressure between the inner chamber 36 and the outside.
7 is formed through the hole.

In FIG. 8, an outward seaming part 40 is formed at the joint 39 of the chamber part 38, and this seaming part 40 is connected to the mold body 4.
It is clamped and fixed by a mounting groove 44 made of a recess 42 on the first side and a ring material 43 welded to the mold body 41 so as to cover the recess 42.

An inner chamber 45 is provided between the mold body 41 and the chamber portion 38.
I was trying to form a. In addition, flow passages 46 and 47 for adjusting the air pressure between the inner chamber 36 and the outside are provided in the mold body 41, respectively.
and a recess is provided in the ring material 43 to connect these.

[Problems to be Solved by the Invention] In the conventional differential heat sensor described above, the chamber part 3
3.38 Since the joint part 34.39 of the oka edge was brought into contact with the mold body 31.41 by adhesive 35 or pressure bonding over its entire circumference, the joint part 34.39 was moved from the joint part 34.39 to the mold body 31.41. A heat dissipation phenomenon occurs,
This has the disadvantage that it may affect the sensitivity characteristics of the sensor.

Further, there is the inconvenience of having to separately provide a flow passage 37 or 46.47 for adjusting the air pressure between the inner chambers 36, 45 and the outside.Moreover, in the case of FIG.
This has the drawback that the positioning of the parts must be adjusted and manufacturing is troublesome.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and as a means for solving the problems, the present invention provides a mold body having an annular mounting groove on one peripheral edge, and a mold body having an annular mounting groove on one peripheral edge thereof. It includes a contact supported via a spring plate, and a chamber portion that forms a heat-sensitive chamber therein with at least a heat-sensitive plate and a diaphragm, and displaces the diaphragm to close the contact when the temperature inside the heat-sensitive chamber increases rapidly. , in a differential heat sensor in which a joint portion on the periphery of the chamber portion is joined to the mounting groove to form an inner chamber between the mold body and the chamber portion, the back surface of the mold body within the mounting groove of the mold body; A plurality of protrusions are formed at intervals at side positions, and the plurality of protrusions and the joint part of the periphery of the chamber part are fixed by adhesive or welding, and between the plurality of protrusions m between the plurality of protrusions. It is configured to form a flow path that adjusts the air pressure between the inner chamber and the outside.

r Example] Embodiments of the present invention will be described below based on the drawings.

1 to 6 are diagrams showing an embodiment of the invention.

The differential heat sensor of this embodiment includes a mold body 1, a contact 2, and a chamber part 3.

The mold body 1 is made of synthetic resin, and is provided with a fitting piece 4 on the back side, which is adapted to be fitted to a mounting base (not shown) on a ceiling or the like. There is. Furthermore, a recess 6 for forming an inner chamber 5 between the mold body 1 and the chamber portion 3 is provided in the center of the front surface of the mold body 1 . Furthermore, an annular mounting groove 7 for mounting the chamber section 3 is formed on the peripheral edge of the front surface (the outer periphery of the four sections 6). This mounting groove 7 has convex portions 7a formed at four symmetrical positions. The convex portions 7a are formed at positions on the back side of the mold body 1 within the mounting grooves 7a, and the convex portions 7a are arranged at intervals from each other.

The contact 2 has a fixed contact 8 and a movable contact 9, and the fixed contact 8 and the movable contact 9 are each provided on one end side of a spring plate 10.11, and the other end side of these spring plates 10. 12, the fixed contact 8 is fixed at an appropriate position in the recess 6.
and a movable contact 9 are opposed and supported approximately at the center of the four parts 6. In addition, an adjustment screw 13 is screwed into and protrudes from the rear side of the central position n of the recess 6, so that it can come into contact with the rear side of the spring plate 10, and the position t of the fixed contact 8 is adjusted. 8 and the movable contact 9 can be adjusted.

The chamber part 3 is for heat sensing, and has a heat sensitive chamber inside by joining the curved heat sensitive plate work 4 on the front side and the periphery of the diaphragm mounting frame 28 to which the diaphragm 15 on the back side is attached by soldering etc. 16 is formed. This chamber portion 3 has a peripheral joint portion (a joint portion between the heat sensitive plate 14 and the diaphragm mounting frame 28) 17 connected to the mounting groove 7 of the mold body 1.
It is joined to the convex portion 7a of the mold body l so as to cover the four parts 6 of the mold body l. The joint part 17 has a heat-sensitive plate 14 at its end.
The diaphragm mounting frame 28 is bent outward to form a seaming part 18, and a stepped part 19 is formed by bending the heat-sensitive plate 14 to form a step toward the center at a position adjacent to the seaming part 18. I am trying to set it up. And the joint part 17
When joining the mold body 1 to the mounting groove 7, the joint part 17 is heated by high-frequency induction heating, and is inserted into the mounting groove 7 of the mold body 1 to bring the joint part 17 into contact with the convex part 7a in the mounting i17. As a result, the synthetic resin material of the convex portion 7a is melted and welded. In this case, the molten synthetic resin material flows into the stepped portion 19 and hardens, forming a protrusion 20 for preventing pull-out, thereby ensuring reliable joining. In addition, since most of the molten synthetic resin material flows into the stepped portion 19, it does not flow out to the surface side, giving a good appearance.The outside of the joint portion 17 is flush with the exception of the stepped portion 19. In this high-frequency induction heating, the metal joint 17 near the heating coil is heated to the highest temperature, and only the synthetic resin part that comes into contact can be melted and fused, minimizing deterioration of other parts due to heating. It's funny what you do.

In this way, by welding the joint part 17 and the convex part 7a in the mounting yt7, the contact part between the chamber part 3 and the mold body l is only a part of the joint part 17, and the chamber part 3
The sensitivity characteristics of the sensor are improved by suppressing heat radiation from the mold body to the mold body l. Furthermore, when welding and fixing the convex portions 7a in the mounting groove 7 and the joint portion 17, a flow passage 5a for adjusting the air pressure in the inner chamber 5 and the outside is formed at the same time in the gaps between the plurality of convex portions 7a. I have to. Therefore, there is no need to separately form a flow path.

Further, the chamber part 3 can open and close the contacts 2 by operating the spring plate 11 by the displacement of the diaphragm 15 caused by the expansion of air due to temperature changes in the heat-sensitive chamber 16 and moving the movable contact 9. There is. in this case,
The diaphragm mounting frame 28 is provided with a leak hole 21 that allows air thermally expanded due to a slow temperature rise to escape, and this leak hole 21 allows the diaphragm 15 to be displaced only when the temperature inside the heat sensitive chamber 16 suddenly rises to detect a fire. That's what I do.

In this embodiment, high-frequency induction heating is used as the first stage of welding the convex portion 7a of the mounting groove 7 and the joint portion 17, but the present invention is not limited to this, and means such as ultrasonic welding and high-frequency dielectric heating may also be employed. It is something.

Moreover, instead of the welding means, means for fixing the convex portion 7a of the mounting groove 7 and the joint portion 17 using an adhesive may also be adopted.

[Effects of the Invention] As explained above, the differential heat sensor of the present invention has a plurality of convex portions formed at intervals at the end position of the joint portion of the mounting groove on the peripheral edge of the mold body. Because the protrusion and the joint on the periphery of the chamber are fixed by adhesive or welding, the connection from the chamber to the mold body is faster than when the entire circumference of the joint is fixed to the mounting groove by adhesive or welding. This has the effect that heat radiation can be suppressed and the sensitivity characteristics of the sensor can be improved.

In addition, when fixing the above-mentioned protrusions and joints, we decided to form a flow passage to adjust the internal and external air pressure in the gaps between the plurality of protrusions, so a pressure adjustment flow passage was separately provided. There is no need for positioning for connection of flow channels during manufacturing as in the conventional method, and there is an effect that manufacturing can be performed simply and easily.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an enlarged main part of a differential heat sensor according to an embodiment of the present invention, Fig. 2 is an overall longitudinal sectional view of this embodiment, and Fig. 3 shows a mold body. 4 is an exploded partial cross-sectional view showing the essential parts of this embodiment in an enlarged manner. FIG. 5 is a cross-sectional view of the convex portion in the assembled state, and FIG. 6 is a cross-sectional view of the portion between the convex portions. 7 are partially enlarged sectional views showing a conventional example, and FIG. 8 is a partially enlarged sectional view showing another conventional example. 1.22: %-old body 2: vi point 3.26: Chamber portion 5a, 29.298 + flow path 7.30: Mounting groove 7a, 24: Convex portion 10.11
: Spring plate 14: Thermal plate 15: Diaphragm
16: Heat sensitive chamber 17.27: Joint part

Claims (1)

[Scope of Claims] A mold body having an annular mounting groove on the peripheral edge, a contact point supported by the mold body via a spring plate, and at least a heat-sensitive plate and a diaphragm to form a heat-sensitive chamber therein. a chamber portion that displaces the diaphragm and closes the contact point when the temperature of the mold body suddenly increases; In the differential heat sensor forming a chamber, a plurality of convex portions are formed at intervals on the back side of the mold body within the mounting groove of the mold body, and the plurality of convex portions and the periphery of the chamber portion are joined. The differential heat sensor is characterized in that the plurality of convex parts are fixed by adhesive or welding, and a flow path is formed in the gap between the plurality of convex parts to adjust the air pressure between the inner chamber and the outside.