JPH0546154Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a structure for maintaining the air pressure within a differential heat sensor for detecting fire to be the same as the outside air.

[Background Art] As shown in FIG. 9, a conventional heat sensor includes a heat-sensitive block 2 composed of a heat-sensitive plate 4, a seal plate 6, and a diaphragm 5. Diaphragm 5 due to expansion and contraction of air in heat-sensitive chamber 7 formed in 5
The contact 9 is opened and closed by a displacement of There is a so-called differential type in which the diaphragm 5 is pushed upward and the contacts 9 are closed only when the temperature rises rapidly.

In this differential heat sensor, the contact 9
is fixed to the contact spring 15, and the contact spring 15 is driven by the displacement of the diaphragm 5 to open and close the contact 9.
is arranged in a contact storage chamber 23 formed between the heat-sensitive block 2 and the body 1.

In such a differential heat sensor, in order to enable good differential heat sensing operation, it is necessary to maintain the air pressure inside the differential heat sensor at the same state as the outside air.

Therefore, conventionally, as shown in FIGS. 10 and 11, an insertion hole 21 is formed in the body 1 that communicates with the contact storage chamber 23, and through this insertion hole 21, the air pressure inside the differential heat sensor can be adjusted to the same level as the outside air. I try to keep it at that. In addition, in the case of the above-mentioned differential heat sensor, there is a protrusion 20 on the bottom surface of the body 1 (mounting surface to the ceiling, etc.).
is formed, and the insertion hole 21 is bored in this protrusion 20.

However, if the insertion hole 21 is provided on the lower surface side of the body 1 in this manner, water leaking from the ceiling or the like may enter the interior through the insertion hole 21, and the differential heat sensor may be damaged.

In addition, as another method, as shown in FIG.
There is a method of providing a gap 22 and allowing air to escape through this gap 22. However, in this case, the gap 22 becomes large, and there is a fear that dirt and dust may enter through the gap 22 and cause malfunction.

[Purpose of the invention] The present invention was made in view of the above points, and its purpose is to create a differential heating system that is free from the risk of water intrusion and also has little risk of dust and dust entering. The purpose is to provide a sensor.

[Disclosure of the invention] (Example) An embodiment of the invention is shown in FIGS. 1 to 8.
The differential heat sensor of this embodiment has the same basic configuration as described above, and a heat-sensitive block 2 is composed of a heat-sensitive plate 4, a diaphragm 5, and a seal plate 6. A contact storage chamber 23 is formed between the heat-sensitive block 2 and the body 1 to house the contact spring 15 and the contact 9. There is.

The characteristic feature of this embodiment is that the heat-sensitive block 2 is not attached directly to the body 1, but a ring-shaped fixing member 3 is used, and the fixing member 3 and the body 1 are in contact with each other. The point is that a small gap is partially formed in the portion to communicate the contact storage chamber 23 with the outside.

The configuration of this embodiment will be explained in further detail below.

The heat-sensitive plate 4 and seal plate 6 constituting the heat-sensitive block 2 are seamed and combined into one body as shown in FIG. 5, and the seamed portion is held between the body 1 and the fixing member 3. The heat-sensitive block 2 is fixed to the body 1 by means of the heat-sensitive block 2. Incidentally, the heat-sensitive plate 4 is coated with melanin baking coating to improve its thermal response.

The body 1 is formed into a circular shape as shown in FIG. 1, and has a mounting portion 24 for mounting the fixing member 3 on the outer periphery of the upper surface to which the heat-sensitive block 2 is mounted.

This mounting part 24 is shown in FIG.
As shown in FIG. 2, which is an enlarged view of the part, there is a protrusion 10 circumferentially provided slightly inside the outermost periphery of the body 1, and the inner circumferential side of this protrusion 10 is lowered one step as shown in FIG. The contact portion 13 is formed by lowering the inner peripheral side of the step portion 12 by one step.

A rib 11 for partially welding the fixing member 3 is formed on the stepped portion 12. and,
With the heat sensitive block 2 placed on the body 1,
The seaming part of the heat-sensitive block 2 is the contact part 13
placed on top. Further, grooves 16 are partially formed in this mounting portion 24. Incidentally, FIG. 3 shows a view of the groove 16 forming portion of the body 1 viewed from the outside.

The inside of the mounting portion 24 of the body 1 is formed lower, and two contact springs 15 each having a contact 9 fixed to its tip end are attached to this portion (see FIG. 9). Here, the contact springs 15 are attached using fixing screws 14, and each contact spring 15 is
are attached so that the contacts 9 face each other.

By the way, the part related to this embodiment corresponds to a so-called sensor head that senses heat, and a sensor base containing a built-in sensing circuit is installed on the ceiling, and the sensor head can be attached to and removed from the sensor base. Can be installed freely. Therefore, for attachment to the sensor base, a connecting terminal 19 is provided on the lower surface of the body 1, and this connecting terminal 19 is also fixed together with the contact spring 15 using the fixing screw 14. Note that mechanical and electrical connection to the sensor base is made through the connection terminal 19.

The fixing member 3 is made of synthetic resin, and its outer shape is sized to approximately match the mounting portion 24 of the body 1. A protrusion 17 is formed at a position corresponding to the stepped portion 12 of the body 1 of the fixing member 3, and a protrusion 18 having a triangular cross section is further formed along the center of the protrusion 17.

The assembly of the differential heat sensor of this example consists of body 1
The heat-sensitive block 2 is temporarily fixed by being sandwiched inside the stepped portion 12 of the heat-sensitive block 2, and in this state, the fixing member 3 is pressed and fitted to the outer periphery of the heat-sensitive block 2. As a result, the seaming portion of the heat-sensitive block 2 is held between the abutting portion 13 and the inner peripheral portion of the protrusion 17 of the fixing member 3 corresponding to the abutting portion 13.

Then, ultrasonic waves are applied to the protrusions 18 of the fixing member 3 that are in contact with the ribs 11 formed on the step portion 12 to melt them, thereby welding the ribs 11 and the protrusions 18 together. In other words,
The protrusion 18 functions as a so-called energy director. In this state, the fixing member 3 is brought into close contact with the mounting portion 24 of the body 1.

When the fixing member 3 is welded to the body 1 in this way, the seaming part of the heat-sensitive block 2 is attached to the fixing member 3.
and the body 1 and are fixed.

By the way, as described above, the fixing member 3 is brought into close contact with the attachment part 24 of the body 1 to keep the inside airtight, but in the case of this embodiment, the groove 16 is formed in the attachment part 24 as described above. , so the contact storage chamber 2 is formed in the groove 16 of the mounting portion 24.
3 to the outside is formed, and through this small gap, the air in the contact storage chamber 23 can escape to the outside as shown by the broken line arrow in FIG.

When the contact storage chamber 23 is communicated with the outside in this manner, there is no fear that water leaking from the ceiling will enter, and furthermore, dust and dust can be prevented from entering the contact storage chamber 23. Moreover, in the case of this embodiment, since the small gaps are formed in a step-like manner, the effect of preventing dirt and dust from entering into the contact storage chamber 23 is enhanced.

In the case of this embodiment, the fixing member 3 and the body 1 are sandwiched and fixed, and a contact storage chamber 23 is provided inside.
Although the seaming portion between the heat-sensitive plate 4 and the sealing plate 6 is used as the protrusion for forming the protrusion, it goes without saying that the protrusion may be formed individually.

[Effects of the invention] As described above, the present invention includes a heat-sensitive block composed of a heat-sensitive plate and a diaphragm, a body to which the heat-sensitive block is attached, a fixing member for fixing the heat-sensitive block to the body, and the heat-sensitive plate and diaphragm. A contact spring is driven by the displacement of a diaphragm due to the expansion and contraction of air in the heat-sensitive chamber formed by the heat-sensitive block, and a contact is opened and closed by the drive of the contact spring. A heat-sensitive block is placed around the body so as to protrude outward, and the contact spring and the contact are arranged in a contact storage chamber formed inside the protrusion, and the heat-sensitive block is placed on the body. A stepped part that covers the outer periphery of the protruding part with the heat-sensitive block placed thereon is provided on the outer periphery of the abutting part of the body that the protruding part of the heat-sensitive block comes into contact with, and the protruding part of the heat-sensitive block is placed between the protruding part of the heat-sensitive block and the abutting part of the body. The fixing member is attached to the body by welding it to the stepped part while being held between the heat-sensitive blocks, and continuous grooves are formed between the protrusion of the heat-sensitive block and the abutting part of the body, and between the fixing member and the stepped part of the body. Since the groove forms a small gap that communicates the contact storage chamber with the outside, the contact storage chamber is communicated with the outside air through the small gap, and the air pressure inside the differential heat sensor can be changed to follow the outside air. This allows the differential heat sensor to operate well, and since a small gap is formed at the contact area between the fixing member and the body, water leaking from the ceiling etc. will not enter. Also, since the gap is small, it is possible to prevent dirt and dust from entering, and it is possible to prevent dust and dirt from becoming inoperable.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the body of an embodiment of the present invention, Fig. 2 is an enlarged perspective view of section A in Fig. 1,
Figure 3 is a side view of section A in Figure 1 seen from the outside;
Figure 4 is a partially cutaway side view of the heat-sensitive block.
5 is an enlarged sectional view of part B in FIG. 4, FIG. 6 is a plan view of the fixing member, and FIG. 7 is an enlarged sectional view of section A in FIG.
An enlarged sectional view taken along line A', Fig. 8 is a sectional view showing the function of the small gap, Fig. 9 is a sectional view showing the configuration of a conventional differential heat sensor, and Fig. 10 is a conventional contact storage. FIG. 11 is an enlarged cross-sectional view of the same essential parts as above, and FIGS. 12a and 12b are explanatory diagrams of another conventional structure for communicating a contact storage chamber with the outside. 1 is a body, 2 is a heat-sensitive block, 3 is a fixing member, 4 is a heat-sensitive plate, 5 is a diaphragm, 7 is a heat-sensitive chamber, 9 is a contact, 15 is a contact spring, 16 is a groove, 23
is the contact storage chamber.

Claims (1)

[Scope of utility model claims] Expansion and contraction of air in a heat-sensitive chamber formed by a heat-sensitive block composed of a heat-sensitive plate and a diaphragm, a body to which the heat-sensitive block is attached, a fixing member that fixes the heat-sensitive block to the body, and the heat-sensitive plate and the diaphragm. a contact spring driven by the displacement of a diaphragm, and a contact that opens and closes by the drive of the contact spring, and a protrusion is provided around the outer periphery of the surface facing the body of the heat-sensitive block, protruding toward the body and outward. , the contact spring and the contact are arranged in a contact storage chamber formed inside the protrusion by placing the heat-sensitive block on the body, and a step is provided to cover the outer periphery of the protrusion with the heat-sensitive block placed on the body. A fixing member is provided on the outer periphery of the abutting part of the body that the protruding part of the heat-sensitive block comes into contact with, and the fixing member is welded to the stepped part in such a way that the protruding part of the heat-sensitive block is sandwiched between the protruding part of the heat-sensitive block and the abutting part of the body. A continuous groove is formed between the protrusion of the heat-sensitive block and the abutting part of the body, and between the fixing member and the stepped part of the body, and this groove creates a small gap that communicates the contact storage chamber with the outside. A differential heat sensor characterized by comprising: