heat detector

Abstract

To provide a heat detector for fire alarm that can obtain good heat-receiving characteristics while thinning the device.SOLUTION: In a fire alarm 1-1, a heat detection unit 5 includes: a lead part 5b that is attached to a circuit board 41 toward a cover 3; and a heat-sensitive part 5a that is provided at the tip of the lead part 5b and located inside the cover 3. A through hole 3c is formed in the cover 3 at a position opposite the heat-sensitive part 5a of a heat detection unit 5, and a through hole 41b and / or a notch is formed in the circuit board 41 at a position around an attachment position of the heat detection unit 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat detector for fire alarm.

[0002] Conventionally, for example, heat detectors in automatic fire alarm systems (hereinafter simply referred to as "heat detectors") have been used. ) and heat detection residential fire alarms (hereinafter simply referred to as "fire alarms"). , a heat detector is used.

[0003] This type of heat detector for fire alarms, whether it is a heat detector or a fire alarm, has a heat-sensitive part. It is equipped with a heat detection unit such as a thermistor, and in the event of a fire, detects the hot air currents generated by the fire. A fire is detected when heat is transmitted to the heat-sensing element and the output value of the heat detection element exceeds a certain value. After detecting a fire, in the case of a heat detector, a fire signal is output to the receiver to notify the occurrence of a fire. In the case of a fire alarm, a sound or buzzer is emitted from a sound output means such as a speaker provided in the device itself. The heat detector will sound a fire alarm. Even in this case, the circuit board is attached to the main body and is removed from the cover that covers the main body. It is provided so that it protrudes to the side, and space is provided around it to enable efficient heat reception. For this reason, the heat-sensing part at the tip is located outside the cover (for example, See Patent Document 1. For an example of a fire alarm, see Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-287374 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-141568 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional heat detectors for fire alarms have the following characteristics: The thickness of the entire device is increased because a protector must be installed on the outside of the cover to protect the hot parts. If the device is made thinner by placing the heat-sensing part inside the cover, the internal The heat of the hot air flow is absorbed by the components, etc., so the temperature of the hot air flow when passing around the heat-sensing part As a result, it is necessary to place the heat-sensitive part outside the cover and provide a protector. The heat receiving characteristics may be worse than those of the conventional type.

[0006] In the case of fire alarms, batteries and speakers are installed inside the device, but not in heat detectors. Since components are also installed, the heat absorbed by the components inside the device is less than that of a heat detector. This may result in a further deterioration of the heat receiving characteristics of the heat sensing part.

[0007] In view of the above circumstances, the present invention provides a thermal sensor that can provide good heat receiving characteristics while making the device thinner. The purpose is to provide a tool.

[0008] Here, the heat receiving characteristic refers to the difference between the actual temperature of the hot air flow and the temperature detected by the heat detection unit, The deterioration of heat reception characteristics means that the difference between the actual temperature and the detected temperature becomes large. Obtaining good heat receiving characteristics means that the difference can be reduced. [Means for solving the problem]

[0009] The first aspect of the present invention is a device comprising a main body, a cover attached to the main body, and a front cover. a circuit board located between the cover and the circuit board; and a heat detection unit attached to the circuit board. the heat detecting portion is attached to the circuit board facing the cover. and a heat-sensing part provided at the tip of the lead part and positioned inside the cover. The cover has a through hole formed at a position facing the heat-sensing part of the heat detection part. The circuit board is provided with through holes and / or is a heat detector characterized by having a notch formed therein.

[0010] In the first aspect of the present invention, the cover has a peripheral surface portion, and the peripheral surface portion is provided with the A through hole is formed at a position on the outer periphery of the space formed between the main body and the circuit board. It is possible.

[0011] In addition, a second aspect of the present invention is a circuit board in which the through holes and / or notches are Instead of being provided with a portion formed on the outer edge, a narrow shape is formed on the outer edge portion and protrudes outward. and a protruding mounting portion to which the lead portion of the heat detecting unit is attached. This is a heat detector that features:

[0012] In a second aspect of the present invention, the circuit board has at least two of the protruding mounting portions, which are opposite to each other. The heat detectors are provided on opposite sides of the outer edge of the device, and the heat detectors are located on the opposite sides of the outer edge of the device. At least two of them may be provided, attached to each of the attachment parts.

[0013] Furthermore, the third aspect of the present invention is a type having the lead portion as the heat detecting portion. Instead of providing the above, a chip type with a built-in heat-sensing part is provided on the surface of the circuit board. and the through hole and / or the notch are formed in the circuit board. Instead of providing the above-mentioned chip-type heat detection unit, the chip-type heat detection unit is surface-mounted and attached. The through hole of the cover is provided with: At a position facing the chip-type heat detection unit attached to the flexible substrate unit The heat detector is characterized by being provided with:

[0014] In the third invention, the flexible board portion of the circuit board is disposed at an outer edge of the rigid board portion. The flexible wiring board may be provided so as to protrude toward the outer periphery. The flexible substrate portion has a narrow protrusion formed on the outer edge of the rigid substrate portion. The circuit board may be provided by being connected to the flexible substrate. At least two of the cable substrate portions are located on either side of the outer edge of the cable, opposite each other. The chip-type heat detection unit is attached to each of the flexible substrates. At least two of the circuit boards may be provided. The flexible substrate portion is an extension portion that is bent and extends toward the through hole of the cover. and the chip-type heat detecting unit is attached to the extension portion of the heat detecting unit. can. [Effects of the Invention]

[0015] In any of the first to third inventions, the heat-sensing part of the heat detection unit is located inside the cover. By adopting this configuration, the device can be made thinner.

[0016] In the first aspect of the present invention, the circuit board is arranged around the mounting position of the heat detection unit. In the second invention, a through hole and / or a notch is provided. , and a protruding mounting portion having a narrow width on the outer edge to which the heat detection unit is attached is provided. In the third aspect of the present invention, the circuit board is made thin and narrow, and the heat detection unit can be attached to the circuit board. In any of these inventions, the flexible substrate portion has a thickness of It is possible to improve the flow of hot air that flows into the inside of the device and flows around the heat-sensing part of the heat detection unit. This makes it possible to obtain good heat receiving characteristics.

[0017] Therefore, according to the present invention, the entire device can be made thinner while still achieving good heat receiving characteristics. A heat detector can be provided. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of the entire device of the first embodiment. Note that in the drawing, the cover side is shown as the top and the base side as the bottom, but when installed on a ceiling surface, for example, the top and bottom are reversed. [Figure 2] FIG. 2 is a top view of the entire device according to the embodiment of the present invention. [Figure 3] FIG. 2 is a top view of a portion of a circuit board according to the embodiment of the present invention; [Figure 4] FIG. 10 is a view corresponding to FIG. 1 of the second embodiment. [Figure 5] FIG. 3 is a view corresponding to FIG. 2 of the embodiment. [Figure 6] FIG. 10 is a view corresponding to FIG. 1 of the third embodiment. [Figure 7] FIG. 4 is a view corresponding to FIG. 3 of the embodiment. [Figure 8] FIG. 10 is a view corresponding to FIG. 1 of the fourth embodiment. [Figure 9] FIG. 3 is a view corresponding to FIG. 2 of the embodiment. [Figure 10] FIG. 10 is a view corresponding to FIG. 1 of the fifth embodiment. [Figure 11] 1A and 1B are a top view and a side view, respectively, of a circuit board portion of the embodiment of the present invention. [Figure 12] FIG. 10 is a view corresponding to FIG. 1 of the sixth embodiment. [Figure 13] FIG. 3 is a view corresponding to FIG. 2 of the embodiment. [Figure 14] FIG. 13 is a view corresponding to FIG. 11 of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following describes an embodiment of the present invention, taking as an example a case where the invention is applied to a heat detection type residential fire alarm. However, the present invention is not limited to such a fire alarm. It can also be applied to other heat detectors, such as heat detectors in automatic fire alarm systems. In the following description, terms indicating positions and directions such as "upper" and "lower" are used in the drawings. It is used according to the position and direction above.

[0020] [First embodiment (corresponding to the first invention)] First, a fire alarm 1-1 according to a first embodiment will be described with reference to FIGS. 1 to 3. do.

[0021] ·Basic configuration As shown in FIGS. 1 and 2, the fire alarm 1-1 includes a main body 2 and a The cover 3, the circuit board 41 located between the main body 2 and the cover 3, and the circuit board 41 attached to the cover 3. The fire alarm 1-1 is equipped with a heat detection unit 5 that can be attached to a mounting base. Although not shown in the drawings, the base 6 is fixed to an installation surface such as a ceiling surface by screws or the like. The fire alarm 1-1 is fixed to the ceiling, and the main body 2 is attached to the base 6. It is installed on the installation surface such as the surface of a well.

[0022] Main unit The main body 2 has a disk-shaped middle plate 2a. The circuit board 41 is supported on the middle plate 2a. On the middle plate 2a, various components such as a battery storage section and a speaker are mounted, as will be described in detail later. is further provided.

[0023] ·cover The cover 3 has a disk-shaped upper surface portion 3a and a cylindrical peripheral surface portion 3b that is continuous with the periphery of the upper surface portion 3a. The cover 3 is cylindrical in shape and is attached to the main body 2, and together with the main body 2, the cover 3 is connected to the circuit board. A housing is formed in which various components such as the plate 41 are housed.

[0024] The upper surface 3a is provided with a vertically extending heat-sensitive portion 5a of the heat detection unit 5, which will be described later. The peripheral surface portion 3b is provided with a vertical hole 3c formed as a through hole. 1 At a position corresponding to the upper internal space, a circumferentially slit-shaped through hole and a horizontally oriented through hole are provided. and an upper slit 3d formed as above, at a position corresponding to the internal space below the circuit board 41, The lower slit 3e is formed as a circumferentially slit-shaped through hole in the horizontal direction. These vertical holes 3c, upper slits 3d, and lower slits 3e are all It functions as a flow area for hot air when it is generated.

[0025] In this embodiment, the vertical hole 3c has a tapered shape from the edge of the hole toward the center. It is formed to protrude in a shape similar to that of a protective film for the heat-sensitive part 5a of the heat detection part 5, which will be described later. There are provided a plurality of protruding pieces 3ca that function as a heat exchanger. Even if the diameter of the vertical hole 3c is made larger to improve the thermal measurement, the protrusion 3ca The vertical hole 3c can protect the heat-sensing part 5a of the heat detection part 5. The vertical hole 3a is formed around the position where the vertical hole 3a faces the vertical hole 3a. The hot airflow flowing in from the center is guided to the center by the protruding piece 3ca, and the heat sensing of the heat detection unit 5 The flow can be directed toward the portion 5a.

[0026] Although not shown in the figure, the upper slit 3d and the lower slit 3e are formed by a columnar structure in the height direction. The plurality of members are partitioned by the members and are provided in the circumferential direction over the entire circumference, and The upper slit 3d is partitioned by a blade-shaped member in the circumferential direction, and is divided into a plurality of vertical slits (see FIG. In the example shown, two slits (top and bottom) are provided. , can be changed as appropriate.

[0027] Heat detection unit (lead type) The heat detection unit 5 is a heat detection element having a lead portion 5b and a heat-sensing portion 5a provided at the tip side of the lead portion 5b. The heat detection unit 5 is, for example, a heat detection element such as a lead-type thermistor. In this embodiment, there is one heat detection unit 5, and the lead unit 5b covers the 3, and the heat-sensing part 5a is positioned inside the cover 3. The base end of the board portion 5b is electrically connected to the circuit board 4 and is attached to the circuit board 4. do.

[0028] Here, as described above, the heat-sensing part 5a is located inside the cover 3. There is no need to provide a protector that protrudes outward (to the front side) from the upper surface portion 3a of the cover 3. The upper surface 3a of the fire alarm 1-1 can be made flat. The device can be made thinner.

[0029] In this embodiment, the lead portion 5b of the heat detection unit 5 is vertically disposed on the circuit board 41. However, it may be mounted at an angle.

[0030] Circuit board The circuit board 41 has a rectangular flat plate shape and is located between the main body 2 and the cover 3 as described above. The circuit board 41 is supported on the middle plate 2a of the main body 2 in the above-described position. The heat detection unit 5 is attached at the center of the heat detection unit 5. The mounting position corresponds to the center position of the upper surface 3a of the cover 3. The vertical hole 3c, which the heat-sensing part 5a faces, is provided at the center of the upper surface part 3a of the cover 3.

[0031] Cutouts / Through holes 3, the circuit board 41 is provided with a heat detecting section 5 around the mounting position. At this position, a notch 41a and a through hole 41b are provided.

[0032] In this embodiment, both the notch 41a and the through hole 41b are provided in the circuit board 41. However, it is also possible to provide only one of them. The cutouts 41a and through holes 41b are provided on all four sides around the mounting position of the part 5. However, it may be provided on at least one of the peripheries.

[0033] Here, in the fire alarm 1-1, the notch 41a and the through hole 41 b is provided, which will be explained later, so that the heat flowing into the housing and the heat detection unit 5 The flow of hot air that hits the heating portion 5a and flows around it can be improved, resulting in good heat reception. characteristics can be obtained.

[0034] In this embodiment, the notch 41a is formed at a position from the outer edge of the circuit board 41 to the center of the heat detection unit 5. The cutouts on the opposing long sides of the circuit board 41 extend to the vicinity of the mounting position. The two, one on each side, extend along the short side and are located on the side of the mounting position of the heat detection unit 5. The ends of the heat detecting unit 5 are arranged to face each other. The through hole 41b has a straight, elongated shape with an arc-shaped end on the mounting position side. The heat detection units 5 are to be installed in two positions in the middle, aligned in the long side direction. The notch 41a and the through hole 41b are the same in shape and are circular. The number and shape of 1b can be changed as appropriate.

[0035] Thermal air flow When a fire occurs, if the source of the fire is directly below the fire alarm 1-1, the hot air current rising from the source of the fire will As shown by the arrow in FIG. 1, a vertical hole 3c is provided at the center of the upper surface 3a of the cover 3. At this time, the hot airflow hits the heat-sensing part 5a of the heat detection part 5. The flow will be downwards along the side of the road (same A1), but ahead of the road, there will be a cut-off Since the notch 41a and the through hole 41b are located, the notch 41a and the through hole 41b are The air flows smoothly and passes through the cutout portion 41a and the through-hole 41b (arrow A2).

[0036] That is, in the fire alarm 1-1, the circuit board 41 has a notch 41a or a through hole 4 By providing the vertical hole 3c, the heat-sensitive portion of the heat detection unit 5 is cooled. 5a, improving the flow of hot air (arrow A1) flowing downward along the side. This makes it possible to obtain good heat receiving characteristics.

[0037] Furthermore, in this embodiment, the internal space below the circuit board 41 of the peripheral surface portion 3b of the cover 3 is A lower slit 3e is provided at a position corresponding to the gap, and functions as a hot air flow passage. The hot air current that has passed through the cutout portion 41a and the through hole 41b flows toward the lower slit 3e. The fire alarm 1 flows smoothly and flows out of the housing smoothly (arrow A3). In the case of -1, the heat flows into the housing through the vertical hole 3c and hits the heat-sensitive part 5a of the heat detection part 5. This improves the flow of hot air (arrow A1) flowing downward along the side, resulting in good reception. Thermal properties can be achieved.

[0038] In the fire alarm 1-1, the lead portion 5b of the heat detecting portion 5 is perpendicular to the circuit board 41. However, as mentioned above, it can also be installed at an angle. In this case, although not shown, a notch 4 provided in the circuit board 41 can be used. The position of the through hole 41b and / or the through hole 41a is set to a position that overlaps with the heat-sensing portion 5a of the heat detection unit 5 in a plan view. By doing so, the air that flows into the housing through the vertical hole 3c can be prevented from flowing into the housing. , the heat-sensitive portion 5a of the heat detection unit 5 is hit, and the flow of the hot air flowing downward along the side of the heat detection unit 5 is improved. This makes it possible to obtain good heat receiving characteristics.

[0039] [Second embodiment (corresponding to the second invention)] Next, a fire alarm 1-2 according to a second embodiment will be described with reference to FIGS. do.

[0040] This fire alarm 1-2 differs from the fire alarm 1-1 in that the circuit board The point is that a protruding mounting portion for mounting the heat detection unit is provided on the outer edge of the In addition, the same components as those of the fire alarm 1-1 are explained using the same reference numerals. The details are omitted.

[0041] Protruding mounting part That is, as shown in FIGS. 4 and 5, the fire alarm 1-2 has a circuit board 42 and The lead 5b of the heat detecting part 5 is attached to the thin-shaped portion that protrudes from the edge toward the outer periphery. In this embodiment, the protruding mounting portions 42c are Two, one on each side of the outer edge of the opposite Two heat detection units 5 are attached, one to each of the protruding attachment portions 42c. It is considered to be.

[0042] The upper surface 3a of the cover 3 is provided with a heat detecting unit 5 attached to each of the protruding attachment parts 42c. A vertical hole 3f is provided at a position on the outer periphery facing the heat-sensitive portion 5a. Specifically, the vertical hole 3f has an elongated shape with arc-shaped ends and a slightly curved shape. , and is disposed in a direction intersecting the protruding mounting portion 42c in a plan view.

[0043] In this embodiment, the lead portion 5b of the heat detection unit 5 is attached to the protruding attachment portion of the circuit board 42. It is supposed to be attached vertically to 42c, but it can also be attached diagonally. The two protruding attachment portions 42c may be provided at positions symmetrical in the radial direction. However, they may be provided at positions offset from each other.

[0044] Thermal air flow In this fire alarm 1-2, if the fire source is directly below, the hot air current rising from the fire source As shown by the arrows in FIG. 4, a vertical hole 3f is provided on the outer periphery of the upper surface 3a of the cover 3. At this time, the hot airflow hits the heat-sensing part 5a of the heat detection part 5. The flow will flow downward along the side of the river (same as A4), but there will be a protruding river ahead of the river. Although the mounting portion 42c is provided, the protruding mounting portion 42c has a narrow shape. The air flows smoothly downward in the space to the side of c (arrow A5).

[0045] That is, in the fire alarm 1-2, the protruding mounting portion 42c is provided, so that the vertical The heat flows into the housing through the straight hole 3f, hits the heat-sensitive part 5a of the heat detection part 5, and flows downward along the side of the part. This improves the flow of hot air (arrow A4) flowing in the direction of the arrow, resulting in good heat receiving characteristics. It can be done like this.

[0046] Relationship with other internal components In addition to the circuit board 42, the housing formed by the main body 2 and the cover 3 also contains a speaker 7. The battery compartment 8, the switch section 9, and other components are also housed as built-in components. Components can block the flow of hot air entering the enclosure and can dissipate heat. As described above, the protruding mounting portion 42c protrudes from the outer edge of the circuit board 42 toward the outer periphery. By providing the protruding mounting part at a position away from the other built-in components, In other words, the heat detection unit 42c can be located at a position away from the other built-in components. 5 can be attached. Furthermore, as described above, the protruding attachment portions 42c can be attached to the opposite sides of the At least two on each side of the outer edge By doing so, at least two heat detection units 5 can be provided.

[0047] These also enable the fire alarm 1-2 to obtain good heat receiving characteristics. It is possible.

[0048] [Third embodiment (corresponding to the third invention)] Next, a fire alarm 1-3 according to a third embodiment will be described with reference to FIGS. 6 and 7. do.

[0049] The difference between this fire alarm 1-3 and the above fire alarms 1-1 and 1-2 is that The flip-top type heat detector is attached to the flexible board of the circuit board. The overall layout is similar to that of the fire alarm 1-1. The same components as those of the above-mentioned fire alarms 1-1 and 1-2 are described with the same reference numerals. The details are omitted.

[0050] Heat detection unit (chip type) That is, the fire alarm 1-3, as shown in FIGS. 6 and 7, has a circuit as a heat detection unit 5'. The thermal detection element is a chip type with a built-in heat-sensing part, which is surface-mounted on the circuit board. The sensor 5' may be a heat detecting element such as a chip-type thermistor.

[0051] The heat detecting section 5' is attached to a flexible substrate section 43d of a circuit board 43, which will be described later. The cover 3 is attached to the upper surface 3a of the cover 3 at a position corresponding to the center of the upper surface 3a. On the upper surface 3a, a heat detecting unit 5' is provided at a position facing the heat detecting unit 5', similar to the fire alarm 1-1. A hole 3c is provided.

[0052] In order to prevent deterioration due to the environment, the heat detection unit 5' is coated with a coating material, It can be covered by sticking a film material, etc. In that case, the coating material It is preferable to use a material with high thermal conductivity for the film material.

[0053] Flexible PCB section Furthermore, as shown in FIGS. 6 and 7, the fire alarm 1-3 includes a circuit board 43. A thin and narrow flexible substrate portion 43d on which a top-type heat detection portion 5' is surface-mounted is provided. Equip yourself with what you have.

[0054] Specifically, the circuit board 43 has two rigid board portions 43e, The front panel is positioned in the center between the two rigid board portions 43e and connects them. The circuit board 43 has the flexible board portion 43d. The rigid boards 43e are arranged side by side at a distance from each other on the left and right, and the flexible board section 4 is arranged between them. 3d is extended and positioned, and is supported on the middle plate 2a of the main body 2. There are.

[0055] The circuit board 43 has the fire alarm 1- 1, a space 43f like the notch 41a of the circuit board 41 is provided. The two rigid board parts 43e are provided with the circuit boards of the fire alarm 1-1. A through hole 43g like the through hole 41b of the plate 41 is provided. The substrate 43 has the above-mentioned around the heat detection unit 5' attached to the flexible substrate portion 43d. The space between the notch 41a and the through hole 41b of the circuit board 41 in the fire alarm 1-1 A portion 43f and a through hole 43g are provided.

[0056] Thermal air flow In this fire alarm 1-3, if the fire source is directly below, the hot air current rising from the fire source As shown by the arrow in FIG. 6, the housing 1 is inserted through a vertical hole 3c formed in the upper surface 3a of the cover 3. The heat detector 5' is a chip type and is located in front of the flow direction. The flexible board portion 43d is provided for mounting the chip-type heat sink. After hitting the detection unit 5' and the flexible board unit 43d, the air flows downward along the side of the flexible board unit 43d. At this time, since the flexible board portion 43d is narrow and thin, In addition, a space 43f and a through hole 43g are provided on the side of the This also reduces the amount of heat taken away from the hot air current.

[0057] This allows the fire alarm 1-3 to have good heat receiving characteristics. can be done.

[0058] [Fourth embodiment (same as above)] Next, a fire alarm 1-4 according to a fourth embodiment will be described with reference to FIGS. 8 and 9. do.

[0059] This fire alarm 1-4, like the above-mentioned fire alarm 1-3, has a chip-type heat detection unit. It is supposed to be attached to the flexible board part of the circuit board, but the overall layout structure is as follows: Similar to the fire alarm 1-2, the protruding mounting part is a flexible board part. In addition, the same components as the above fire alarms 1-1 to 3 are the same. The description will be omitted and only reference numerals will be used.

[0060] - Protruding mounting part (flexible board part) That is, the fire alarm 1-4 has a circuit board 44 and other components as shown in FIGS. The flexible substrate is formed as a thin and narrow part that protrudes from the edge to the outer periphery. A protruding mounting portion 44c is provided on which a heat detecting unit 5' of the type is surface-mounted. 44c are opposite to each other, similar to the protruding mounting portion 42c of the circuit board 42 in the fire alarm 1-2. Two, one on each side of the outer periphery of the opposite side, shall be provided. Two detecting units 5' are also attached, one to each of the protruding attachment portions 44c. The number of the protruding attachment parts 44c and the heat detection parts 5' can be changed as needed. In addition, in the circuit board 44, the protruding mounting portion 44c may be provided on the other side. The part is formed as a rigid board part.

[0061] Thermal air flow In this fire alarm 1-4, if the fire source is directly below, the hot air current rising from the fire source As shown by the arrows in FIG. 8, a vertical hole 3f is provided on the outer periphery of the upper surface 3a of the cover 3. The heat flows into the housing from the direction indicated by the arrow A7. The protruding mounting portion 44c is a flexible substrate portion to which the hot air nozzle 5' is attached. The airflow hits the chip-type heat detecting portion 5' and the protruding mounting portion 44c, and flows downward along the side thereof. At this time, the protruding attachment portion 44c is attached to the thin and narrow flexible substrate. The plate portion can reduce the amount of heat taken away from the hot air flow.

[0062] This allows the fire alarm 1-4 to have good heat receiving characteristics. can be done.

[0063] [Fifth embodiment (same as above)] Next, a fire alarm 1-5 according to a fifth embodiment will be described with reference to FIGS. 10 and 11. explain.

[0064] This fire alarm 1-5 is a chip-type heat detector, similar to the above-mentioned fire alarms 1-3 and 1-4. The sensor is attached to the flexible board of the circuit board, but the overall layout The structure is similar to the fire alarm 1-3, but the flexible board part is: An extension portion is provided that is bent and extends toward the vertical hole in the cover. The same components as those of the above-mentioned fire alarms 1-1 to 1-4 are designated by the same reference numerals. The explanation will be omitted.

[0065] Extension part (flexible board part) That is, the fire alarm 1-5 includes a circuit board 45 as shown in FIGS. , and extends toward a vertical hole 3c provided at the center of the upper surface 3a of the cover 3. The chip-type heat detection unit 5' is formed as a thin and narrow flexible substrate. The device has an extension 45d that is surface mounted.

[0066] Specifically, the circuit boards 45 are arranged side by side and spaced apart from each other on the left and right sides and supported on the middle plate 2a of the main body 2. The two rigid board portions 45e are supported by the two rigid A space 45f is formed between the two rigid board portions 45e. 45e and the connecting portion 45c which connects them together. The base end side is bent from the connecting portion 45c, and the tip end side is vertical with the entire body inclined linearly. The heat detecting portion 5 extends to be positioned directly below the center of the hole 3c, and has a chip-type heat detecting portion 5 at its tip end. ' is intended to be surface mounted and has the above-mentioned extension portion 45d.

[0067] Thermal air flow In this fire alarm 1-5, if the fire source is directly below, the hot air current rising from the fire source As shown by the arrow in FIG. 10, a vertical hole is provided at the center of the upper surface 3a of the cover 3. The hot air flows into the housing from 3c (arrow A9). 5' and the extension portion 45d, which is a flexible substrate portion, and flows downward along the side thereof (same A9), but the space 45f is located ahead of the vehicle in the traveling direction. The air flows smoothly toward the space 45f and passes through the space 45f smoothly (arrow A10). When the extension 45d comes into contact with the flexible substrate, the extension 45d is thin and narrow. By being part of the heat exchanger, the amount of heat taken away from the hot air flow can be reduced.

[0068] In other words, in the fire alarm 1-5, the extension portion 45d is provided, so that the vertical hole The heat flows into the housing from 3c, hits the chip-type heat detection unit 5', and flows downward along the side of the chip-type heat detection unit 5'. This improves the flow of hot air (arrow A9) flowing in the direction of the arrow, resulting in good heat receiving characteristics. In addition, the extension portion 45d can be made flexible with a small width and a small thickness. By being a board part, the amount of heat taken away from the hot air current can be reduced, Even in this case, good heat receiving characteristics can be obtained.

[0069] [Sixth embodiment (same as above)] Next, a fire alarm 1-6 according to a sixth embodiment will be described with reference to FIGS. explain.

[0070] This fire alarm 1-6, like the above-mentioned fire alarm 1-5, has a circuit board mounted on a flexible board. The overall arrangement structure is the same as that of the fire alarm. Similar to the alarm 1-2, a protrusion is provided on the outer edge of the circuit board, and an extension is provided on the protrusion. In addition, the same components as the above fire alarms 1-1 to 5 are In such cases, the same reference numerals will be used and the description will be omitted.

[0071] · Protruding / extending parts (flexible board parts) That is, the fire alarm 1-6 includes a circuit board 46 as shown in FIGS. , and has a protruding portion 46c that protrudes from the outer edge toward the outer periphery, and the protruding portion 46c is connected to the tip end side of the cover 3, and is set at a position on the outer periphery side of the upper surface portion 3a of the cover 3 from the tip end side. The flexible substrate portion is bent and extends toward the vertical hole 3f, and has a narrow width and a thin thickness. The thermal sensor 5' is formed as an extension 46d on which a chip-type thermal sensor 5' is surface-mounted. Be prepared.

[0072] This protruding portion 46c is the same as the protruding mounting portion 42c of the circuit board 42 in the fire alarm 1-2. two, one on each side of the outer edge opposite each other, Two extensions 46d are connected to each of the protrusions 46c. The chip-type heat detecting unit 5' also has the extensions 46d. The two protruding portions 46c and the extending portion 46 are surface-mounted. d. The number of heat detection units 5' can be changed as appropriate and may be increased. In this circuit board 46, the portion other than the extension portion 46d is formed as a rigid board portion. do.

[0073] Thermal air flow In this fire alarm 1-6, if the fire source is directly below, the hot air current rising from the fire source As shown by the arrow in FIG. 12, the vertical portion 3a of the cover 3 is provided at a position on the outer periphery thereof. The hot air flows into the inside of the housing through the straight hole 3f (arrow A11). The air hits the detection unit 5' and the extension 46d, which is a flexible substrate, and flows downward along the side thereof. However, there is a space ahead in the direction of travel, so When the air comes into contact with the extension 46d, the air flows smoothly toward the extension 46d (arrow A12). 6d is a thin and narrow flexible board, which reduces the amount of heat taken away from the hot airflow. It can be made easier.

[0074] In other words, the fire alarm 1-6 also has the extension portion 46d, so that the vertical hole The heat flows into the housing from 3f, hits the chip-type heat detection unit 5', and flows downward along the side of the unit. This improves the flow of hot air (arrow A11) flowing in the direction of the In addition, the extension portion 46d is a flexible member having a narrow width and a thin thickness. By using the board part, the amount of heat taken away from the hot air current can be reduced, Even if the temperature is low, good heat receiving characteristics can be obtained.

[0075] [Changes to the implementation form] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. The present invention is not limited to the above, and various modifications are possible within the scope of the invention.

[0076] For example, in all the above-mentioned embodiments, the upper surface 3a of the cover 3 is provided with a heat detection unit 5 or The vertical hole 3c or 3f does not have to be provided at the position facing the heat detection unit 5'. The positions of the substrates 41 to 46 are not limited to between the main body 2 and the cover 3. For example, It may also be between the bases.

[0077] As described above, in the present invention, in the circuit board on which the heat detection unit is mounted, The hot airflow is directed to the rear side of the circuit board (the side without the heat detection unit) around the installation position of the heat detection unit. A hot air flow promoting section (corresponding to a through hole, cutout, or protruding mounting section) is provided to promote the flow to the Therefore, when a vertical hot air current flows into the main body from the through-holes formed in the cover, After heating the heat-sensing part, the hot air current passes through the hot air current driving part and flows to the back side of the circuit board. This allows for smoother hot airflow within the body, resulting in excellent heat reception characteristics. do. [Explanation of symbols]

[0078] 1-1 to 6: Fire alarm (first to sixth embodiments) 2: Main body 2a: Middle plate 3: Cover 3a: Top part 3b: Surrounding part 3c: Vertical hole 3ca: Protrusion 3d: Upper slit 3e: Lower slit 3f: Vertical hole 41: Circuit board (first embodiment) 41a: Notch portion 41b: Through hole 42: Circuit board (second embodiment) 42c: Protruding mounting portion 43: Circuit board (third embodiment) 43d: Flexible board section 43e: Rigid board portion 43f: Space portion 43g: Through hole 44: Circuit board (fourth embodiment) 44c: Protruding mounting portion 45: Circuit board (fifth embodiment) 45c: Connecting portion 45d: Extension portion 45e: Rigid board portion 46: Circuit board (sixth embodiment) 46c: Protrusion 46d: Extension 5: Heat detection part (lead type) 5a: Heat-sensing part 5b: Lead part 5': Heat detection part (chip type) 6: Base 7: Speaker 8: Battery compartment 9: Switch

Claims

1. A heat detector comprising: a main body; a cover having a flat top surface attached to the main body; a circuit board positioned between the main body and the cover; and a heat detection unit attached to the circuit board, The heat detection unit is a chip type with a built-in heat-sensing unit located inside the cover, The cover has a through hole at a position facing the chip-type heat detection unit, The circuit board is a heat detector characterized in that it has a flexible substrate portion with a narrow and thin shape to which the chip-type heat detection unit is surface-mounted and attached, and which is exposed to the hot air flow flowing in through the through hole.

2. A heat detector comprising: a main body; a cover attached to the main body; a circuit board positioned between the main body and the cover; and a heat detection unit attached to the circuit board, The heat detection unit is a chip type with a built-in heat-sensing unit located inside the cover, The cover has a through hole at a position facing the chip-type heat detection unit, the circuit board has a flexible substrate portion having a narrow width and a thin thickness to which the chip-type heat detection unit is attached by surface mounting, and also has two rigid substrate portions arranged side by side and spaced apart from each other; A heat detector, characterized in that the flexible substrate portion is located between the two rigid substrate portions.

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