JP7798477B2 - heat detector - Google Patents

Description

This invention relates to a heat detector used as a fire detector.

Heat detectors are used as fire detectors that detect heat and detect fires. They are installed on the ceilings, walls, etc. of buildings to protect them.

In this type of heat detector, when the heat-sensitive element is exposed from the front of the main body, a protector is provided on the front side of the main body to protect the heat-sensitive element from external forces. Protectors come in a variety of configurations, including one with multiple support posts that protect the heat-sensitive element from the sides and a top plate attached to the tips of the support posts to protect the heat-sensitive element from the front (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2019-159866

In cases where a protector with multiple support posts as described above is installed, gaps are provided between the support posts, and these gaps ensure that hot air can flow toward the heat-sensitive element inside. However, on the other hand, the problem is that the support posts with gaps are visible, which detracts from the aesthetic appearance. In particular, in the case of embedded heat detectors that are installed by embedding them into a ceiling or wall, with only the front part of the main body where the protector is installed exposed, the support posts with gaps become noticeable, further detracting from the aesthetic appearance.

In consideration of the above circumstances, this invention aims to improve the aesthetic appearance of embedded heat detectors.

This invention is an embedded type heat detector comprising a main body, a flat flange provided on the front side of the main body, and a protector provided directly on the front side of the flange to protect a heat-sensitive element, the main body being embedded in a ceiling, wall, etc. with only the front side portion from the flange forward, including the protector, exposed; the heat-sensitive element is a lead-type thermistor provided upright facing forward on a circuit board housed inside the main body, with the tip end portion having a heat-sensitive element exposed forward from the main body via the flange; the protector is provided on the front side of the flange, upright facing forward, and the tip end portion of the thermistor is exposed from the side; and a top plate portion provided at the tip ends of the plurality of support portions to protect the tip end portion of the thermistor from the front, wherein each of the plurality of support portions is located within the range of the vertical projection area of the top plate portion along its entire length, and an angle θ formed between an imaginary line extending axially from the base ends of the plurality of support portions toward the top plate portion and an imaginary line extending from the base ends of the plurality of support portions toward the top plate portion and passing through the outer peripheral edge of the top plate portion is 10 to 50 degrees, the main body has approximately equal lengths in width and height, and the width of the top plate is approximately equal to or longer than the width of the main body .

In the present invention, the angle θ can be set to 15 to 45 degrees .

According to this invention, for example, when a heat detector is mounted on a ceiling or the like, the multiple support posts can be hidden by the top plate from the view of people standing below. Therefore, even in a recessed type where the support posts with gaps in the protector are normally installed in a conspicuous manner, the support posts can be made less visible and less conspicuous, making the aesthetic appearance less likely to be perceived as poor. In other words, the aesthetic appearance of the recessed type heat detector can be improved.

1 shows an example of an embodiment of a heat detector of the present invention, and is a side view of the entire heat detector when the angle θ is 15 degrees. The ceiling side portion is shown with a dashed line to also show the positional relationship with the ceiling side portion when the heat detector is attached to the ceiling. 1 in the case where the angle θ is 45 degrees. 2 is a bottom view (front side of the detector) of the heat detector of FIG. 1. [0023] FIG.

An embodiment of the present invention will now be described with reference to Figures 1 and 2.

Here, terms indicating orientation or position, such as "front" and "rear," used to explain this invention, are used in accordance with the orientation or position of each component relative to the space to be protected, such as inside a building, when installed. Specifically, for example, the side of each component that faces the space to be protected when installed is referred to as the "front," and the opposite side as the "rear."

[Basic configuration]
1 and 2, the heat detector 1 includes a housing 2 (an example of a main body), a flange 3 provided on the front side of the housing 2, and a protector 4 provided on the front side of the flange 3. A circuit board (not shown) is housed inside the housing 2. A heat-sensing element, for example, a lead-type thermistor 6 (see FIG. 3), is attached to and fixed on the circuit board so that it stands upright forward and has its tip end, where the heat-sensing element is located, exposed forward from the housing 2 via the flange 3.

[Installation method (embedded)]
The heat detector 1 is a recessed type and is mounted by embedding it into a ceiling, wall, or the like. Figures 1 and 2 also show the positional relationship with the ceiling T when the detector is mounted to the ceiling T. As shown in the figures, for example, the housing 2, which is the main body, is embedded in a mounting hole H (dashed line) provided in the ceiling T (dashed line) from below to above, with only the front portion including the protector 4 forward of the flange 3 exposed to the space to be protected. Although detailed explanations are omitted, in the illustrated example, the mounting state in the mounting hole H is maintained by the elastic force of a mounting spring 7 (see Figure 3) provided on the side of the main body 2. For convenience, the mounting spring 7 is shown in the figures as being in a substantially free state, not an attached state.

[Protector]
The protector 4 has a structure that protects the thermistor 6 from external forces while ensuring the inflow of hot air toward the thermistor 6 (see FIG. 3 ) located inside, specifically, on the inner periphery of the support posts 4 b. Specifically, the protector 4 has a plurality of support posts 4 b that stand upright toward the front of the flange 3 and are arranged at predetermined intervals (gaps 4 b c , which will be described later) around the thermistor 6 to protect the thermistor 6 from the sides. The protector 4 also has a flat top plate 4 a that is provided at the tip ends 4 b a of the support posts 4 b to protect the thermistor 6 from the front. Gaps 4 b c are provided between the support posts 4 b, which function as inflow ports for the hot air toward the thermistor 6. The top plate 4 a also has a central through-hole 4 a aa (see FIG. 3 ), which penetrates toward the thermistor 6 and functions as an inflow port for the hot air toward the thermistor 6. The gap 4bc and the through hole 4aa ensure that hot air can flow into the thermistor 6.

In the protector 4, each of the multiple support columns 4b is positioned within the vertical projection area of the top plate 4a (inside the outer peripheral edge 4ab of the top plate 4a) along its entire length. In other words, as shown in Figure 3, when facing directly to the front of the heat detector 1, each of the multiple support columns 4b is positioned so that it is completely hidden by the top plate 4a.

As a result, when the heat detector 1 is mounted facing downwards above the space to be protected, such as when it is mounted on a ceiling T, the top plate 4a can hide the multiple support posts 4b from the line of sight of people standing below the mounted heat detector 1. Therefore, even if the heat detector 1 is a recessed type in which the multiple support posts 4b are normally mounted conspicuously, the support posts 4b can be made less visible and less conspicuous, making the aesthetic appearance less likely to be perceived as poor. In other words, the aesthetic appearance can be improved.

The dimensions of each part of the protector 4 will now be explained. The height (length) of the support pillar 4b is preferably set to a length that ensures the inflow of hot air without compromising the aesthetic appearance. For example, it can be set to a length shorter than the height of the housing 2. The thickness of the top plate 4a can be approximately the same as the thickness of the support pillar 4b, or thinner than the thickness of the flange 3. Furthermore, the outer diameter of the top plate 4a can be set to a width that is approximately the same as or shorter than the outer diameter of the housing 2, or approximately half the width of the outer shape of the flange 3.

- Positional relationship between the base end of the support and the outer periphery of the top plate (angle θ)
The extent to which the top plate 4a can hide the support columns 4b is determined by the relationship between the height (length) of the support columns 4b and the size (outer diameter) of the front surface of the top plate 4a. This relationship can be expressed as the angle θ between an imaginary line L1 extending axially from the base ends 4bb of the support columns 4b to the top plate 4a, and an imaginary line L2 extending from the base ends 4bb of the support columns 4b toward the top plate 4a and passing through the outer peripheral edge 4ab of the top plate 4a.

Even when the angle θ is set to 0 degrees, the top plate 4a can obscure the line of sight of a person directly below the heat detector 1. However, this narrows the range of line of sight that can be obscured. Increasing the angle θ can broaden the range of line of sight. The angle θ can be increased by shortening the length of the support columns 4b, but a certain length is necessary to ensure good inflow of hot airflow through the gaps 4bc between the support columns 4b. The angle θ can be increased by increasing the outer diameter of the top plate 4a without shortening the length of the support columns 4b. In other words, the angle θ can be increased while ensuring good inflow of hot airflow. However, if the angle θ is set too large, the outer diameter of the top plate 4a will become too large, which will actually detract from the aesthetic appearance. Therefore, it is considered preferable to set the angle θ to an appropriate angle, for example, between 10 and 50 degrees, or between 15 and 45 degrees. Figure 1 shows an example where the angle θ is set to 15 degrees. Figure 2 shows the case where the outer diameter of the top plate portion 4a is increased and the angle θ is set to 45 degrees.

In the illustrated example, the multiple support columns 4b stand vertically in front of the flange 3, but they may also stand at an angle. Also, while the top plate 4a is circular in plan view (see Figure 3), it may have other shapes, such as a polygonal shape in plan view.

[Small and thin (without cover)]
More specifically, in the illustrated example of the heat detector 1, the flange 3 has a flat plate-like shape, and the protector 4 is provided directly on the front side of the flat flange 3, with no cover covering the front side of the flange 3 between the flange 3 and the protector 4. This allows the front portion exposed from the ceiling T or wall to be made smaller and thinner. In this case, the area occupied by the multiple support columns 4b is larger than the entire exposed front portion, so the multiple support columns 4b would normally be more noticeable. However, as described above, in the heat detector 1, the top plate 4a can obscure the multiple support columns 4b, making them less noticeable and less aesthetically unpleasing. In other words, in the illustrated example, not only can the aesthetic appearance of the heat detector 1 be improved, but it can also be made smaller and thinner.

In the illustrated example, the flange portion 3 is circular in plan view, but like the top plate portion 4a, it may have other shapes, such as a polygonal shape in plan view.

[Configuration change example]
The above describes an embodiment of the present invention with reference to the drawings, taking as an example a case where the present invention is applied to a heat detector. However, the specific configuration is not limited to the above embodiment, and also includes designs within the scope that do not deviate from the gist of the present invention.

1: Heat detector 2: Housing (main body) 3: Flange 4: Protector 4a: Top plate 4aa: Through hole 4ab: Outer rim 4b: Support 4ba: Tip 4bb: Base 4bc: Gap 6: Thermistor 7: Mounting spring T: Ceiling H: Mounting hole

Claims (1)

A built-in heat detector includes a main body, a flat flange provided on the front side of the main body, and a protector provided directly on the front side of the flange to protect a heat-sensitive element, and the main body is embedded in a ceiling, wall, or the like with only the front side portion including the protector forward of the flange exposed,
the heat-sensitive element is a lead-type thermistor that is provided upright toward the front on a circuit board housed inside the main body, and a tip end portion where a heat-sensitive portion is located is exposed forward from the main body via the flange portion,
the protector has a plurality of support columns provided on the front side of the flange portion and standing upright toward the front to protect the tip end portion of the thermistor from the sides, and a top plate portion provided on the tip end portions of the plurality of support columns and protecting the tip end portion of the thermistor from the front, each of the plurality of support columns being located within a vertical projection area of the top plate portion over its entire length, and an angle θ formed by an imaginary line extending from the base ends of the plurality of support columns toward the top plate portion along the axial direction and an imaginary line extending from the base ends of the plurality of support columns toward the top plate portion and passing through the outer circumferential edge of the top plate portion is 10 to 50 degrees,
The main body has a length that is approximately equal to its width and height,
A heat detector characterized in that the width of the top plate is approximately equal to or longer than the width of the main body .