thermal sensor

Abstract

To reduce the thickness of a heat detector.SOLUTION: A heat detector 1 comprises: a housing that is of a cylindrical shape substantially having a lid and a bottom, and includes a main body 21 and a cover 22; a circuit board 30 that is housed in the housing; and heat detection units 315A and 315B attached to the circuit board 30. The circuit board 30 includes a first insertion hole into which the heat detection parts 315A and 315B have been diagonally inserted. Each of the heat detection units 315A and 315B includes: a rod-like lead part; a heat sensitive part connected to one end of the lead part; and a pin connected to the other end of the lead part. The first insertion hole includes: an opening part; and a first notch part that is formed at an edge of the opening part. The circuit board 30 further includes a first land arranged on a first surface so as to surround the first notch part. Pins of the heat detection units 315A and 315B are inserted into the first notch part and tips thereof are soldered to the first land.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a heat detector. [Background technology]

[0002] Conventionally, heat detectors have a heat detection unit such as a thermistor, and detect the occurrence of a fire by detecting the heat of hot air currents generated by the fire. For example, Patent Document 1 describes a heat detector that has a heat detection unit that protrudes outside the housing to facilitate the heat detection of hot air currents. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-141568 Summary of the Invention [Problem to be solved by the invention]

[0004] The heat detector described in Patent Document 1 needs to be provided with a protector to protect the heat-sensing part of the heat detection unit, which causes a problem of increasing the thickness of the heat detector.

[0005] The present invention has been made in view of the above circumstances, and has an object to make a heat detector thinner. [Means for solving the problem]

[0006] In order to solve the above problems, the heat detector of the present invention comprises a housing, a circuit board accommodated in the housing, and a heat detection unit attached to the circuit board, wherein the circuit board has a first insertion hole through which the heat detection unit is inserted at an angle, the heat detection unit has a rod-shaped lead portion, a heat-sensing unit connected to one end of the lead portion, and a pin connected to the other end of the lead portion, the first insertion hole has an opening and a first notch formed on the edge of the opening, the circuit board further has a first land arranged on a first surface so as to surround the first notch, and the pin of the heat detection unit is inserted into the first notch and has its tip soldered to the first land.

[0007] The circuit board may further have a second land arranged on a second surface opposite to the first surface so as to surround the first cutout portion, and a through hole connecting the first land and the second land.

[0008] The first land may not be connected to any circuit mounted on the first surface, while the second land may be connected to any circuit mounted on the second surface.

[0009] The first insertion hole may further have a second notch formed adjacent to the first notch at the edge of the opening, and the circuit board may further have a third land arranged on the first surface to surround the second notch, the first land having a first portion and a second portion facing each other across the first notch, the second portion being arranged closer to the third land than the first portion and narrower in width than the first portion, and the third land having a third portion and a fourth portion facing each other across the second notch, the third portion being arranged closer to the first land than the fourth portion and narrower in width than the fourth portion.

[0010] The heat detector may further include a middle plate housed in the housing and positioned below the circuit board, the middle plate having a second insertion hole through which the heat detection unit is inserted obliquely, the housing having a cover positioned below the middle plate, the middle plate and the cover forming a circulation space through which air flows approximately parallel to the middle plate, and the portion of the middle plate facing the heat detection unit when viewed from the bottom may be formed flat. [Effects of the Invention]

[0011] According to the present invention, the heat detector can be made thinner. [Brief explanation of the drawings]

[0012] [Figure 1] Bottom view of heat detector 1 [Figure 2] Side view of heat detector 1 [Figure 3] Plan view of heat detector 1 [Figure 4] An exploded perspective view of the heat detector 1 with the base 10 removed. [Figure 5] Bottom view of main body 21 [Figure 6] Plan view of main body 21 [Figure 7] Bottom view of circuit board 30 [Figure 8] Plan view of circuit board 30 [Figure 9] A bottom perspective view of the circuit board 30 [Figure 10] FIG. 1 shows the external appearance of the heat detection unit 315. [Figure 11] An enlarged view of the vicinity of the insertion hole 314 shown in FIG. [Figure 12] An enlarged view of the vicinity of the insertion hole 314 shown in FIG. [Figure 13] Cross section of line BB in Figure 12 [Figure 14] An enlarged view of the vicinity of the insertion hole 314 shown in FIG. 8 with the heat detection unit 315 removed. [Figure 15] Cross section of line CC in Figure 14 [Figure 16] Bottom view of the middle plate 50 [Figure 17]2 is a cross-sectional view taken along line AA of FIG. 1, specifically showing only the mid-plate 50, the cover 22, and the heat detection unit 315. [Figure 18] A bottom view of the heat detector 1 with the cover 22 removed. [Figure 19] 1 is a bottom perspective view of the heat detector 1 with the cover 22 removed. [Figure 20] A perspective view of a method for attaching the heat detection unit 315 [Figure 21] A perspective view of a method for attaching the heat detection unit 315 [Figure 22] A perspective view of a method for attaching the heat detection unit 315 [Figure 23] Cross section of line DD in Figure 22 DETAILED DESCRIPTION OF THE INVENTION

[0013] 1. Embodiment A wireless heat detector 1 according to one embodiment of the present invention will be described with reference to the drawings. 1-1.Configuration Fig. 1 is a bottom view of the heat detector 1. Fig. 2 is a side view of the heat detector 1. Fig. 3 is a plan view of the heat detector 1. Fig. 4 is an exploded perspective view of the heat detector 1 with the base 10 removed.

[0014] The heat detector 1 includes a base 10 and a housing 20. The housing 20 houses a circuit board 30, a speaker 40, and a middle plate 50.

[0015] The base 10 has a cylindrical shape with a cover and is fixed to the ceiling with screws or the like.

[0016] The housing 20 has a generally cylindrical shape with a bottom and a lid, and includes a main body 21 and a cover 22 .

[0017] Fig. 5 is a bottom view of the main body 21. Fig. 6 is a plan view of the main body 21. The main body 21 is circular and includes a bottom surface 211, a top surface 212, a battery housing portion 213, a speaker housing portion 214, a circuit board housing portion 215, push-in portions 216A and 216B, antenna holding portions 217A and 217B, and push-in portion holding portions 218A and 218B.

[0018] The bottom surface 211 is the surface facing the circuit board 30 .

[0019] The upper surface 212 is the surface facing the base 10. The open end of the base 10 is fixed to the periphery of the main body 21 on the upper surface 212 side.

[0020] The battery accommodating section 213 is a battery accommodating section that accommodates a cylindrical battery. The accommodated battery is connected to the circuit board 30 and supplies power to each circuit. The battery accommodating section 213 is convex on the bottom surface 211 side of the main body 21 and concave on the top surface 212 side, with the battery accommodated in the concave on the top surface 212 side. The battery accommodating section 213 extends radially from the center of the main body 21 to its periphery when viewed from the bottom.

[0021] The speaker housing portion 214 is a wall portion that protrudes in a substantially vertical direction from the bottom surface 211 of the main body 21, and determines the position of the speaker 40. The speaker housing portion 214 has a substantially C-shape when viewed from the bottom, and is formed so as to be adjacent to the battery housing portion 213.

[0022] The circuit board accommodating portion 215 is a wall portion that protrudes in a substantially vertical direction from the bottom surface 211 of the main body 21, and positions the circuit board 30. The circuit board accommodating portion 215 is formed so as to surround a substantially L-shaped area when viewed from the bottom.

[0023] Push-in portions 216A and 216B are rod-shaped members formed so as to be pushable into bottom surface 211 of main body 21. Push-in portions 216A and 216B are formed by forming a U-shaped through-groove in main body 21 in bottom view. Push-in portions 216A and 216B are formed on the opposite side of speaker accommodating portion 214 across battery accommodating portion 213 in bottom view. Of push-in portions 216A and 216B, push-in portion 216A is arranged so as to come into contact with registration switch 308, which will be described later, and when push-in portion 216A is pressed by the user, registration switch 308 is pressed. On the other hand, push-in portion 216B is arranged so as to come into contact with erase switch 309, which will be described later, and when push-in portion 216B is pressed by the user, erase switch 309 is pressed.

[0024] Antenna holding portions 217A and 217B are rectangular plates that protrude in a substantially vertical direction from the periphery of bottom surface 211 of main body 21, and position antenna 310, which will be described later. Of antenna holding portions 217A and 217B, antenna holding portion 217A is inserted into insertion hole 507 (see FIG. 16) formed in middle plate 50, and positions antenna 310 on bottom surface 501 of middle plate 50. Meanwhile, antenna holding portion 217B is inserted into notch 508 (see FIG. 16) formed in middle plate 50, and positions antenna 310 on bottom surface 501 of middle plate 50. Antenna holding portions 217A and 217B each have a U-shaped groove at its tip, and antenna 310 is clamped within this groove.

[0025] Push-in portion holding portions 218A and 218B are rectangular plates that protrude in a substantially vertical direction from the periphery of bottom surface 211 of main body 21, and position push-in portion 60 (see FIGS. 1 and 4), which will be described later. Push-in portion holding portions 218A and 218B have U-shaped grooves at their tips, and this groove positions shaft portion 61 of push-in portion 60. Of push-in portion holding portions 218A and 218B, push-in portion holding portion 218A further has a U-shaped groove at its tip, and holds antenna 310 within this groove.

[0026] 1 and 2, the cover 22 has a cylindrical shape with a bottom, and its open end is fixed to the periphery of the bottom surface 211 side of the main body 21. The cover 22 has a cylindrical portion 221 and a bottom portion 222.

[0027] The cylindrical portion 221 has 14 air vents 2211 arranged in a circumferential direction. Each air vent 2211 is formed on the bottom portion 222 side of the cylindrical portion 221 and extends elongatedly in the circumferential direction of the cylindrical portion 221. Each air vent 2211 allows a horizontal airflow to flow into the circulation space formed between the cover 22 and the middle plate 50. This horizontal airflow is an airflow that flows approximately parallel to the ceiling surface. The horizontal airflow that flows into the circulation space flows approximately parallel to the middle plate 50.

[0028] The bottom 222 is provided with a push-in portion 60. The push-in portion 60 is a plate having an oval shape when viewed from the bottom, and has a shaft portion 61 at one end thereof (the radially outer side of the cover 22). The push-in portion 60 is attached so as to be able to be pushed into a through-hole formed in the bottom 222. The push-in portion 60 is arranged so as to be able to press an inspection switch 307, which will be described later, and when the user presses the push-in portion 60, the inspection switch 307 is pressed.

[0029] A pair of cover-side holding portions (not shown) having U-shaped grooves (not shown) at their tips are provided on the upper surface side of the bottom portion 222. The pair of cover-side holding portions and the pushing portion holding portions 218A and 218B of the main body 21 sandwich the shaft portion 61 of the pushing portion 60, thereby positioning the pushing portion 60 within the through-hole of the cover 22.

[0030] The bottom 222 further has two vertical holes 2221 formed on its periphery so as to face each other. Each vertical hole 2221 is a substantially oval through-hole, and allows a vertical airflow to flow into the circulation space. This vertical airflow is an airflow that flows in a direction substantially perpendicular to the ceiling surface. The above is the description of the main body 21 and the cover 22.

[0031] Next, the circuit board 30 disposed below the main body 21 will be described. Fig. 7 is a bottom view of the circuit board 30. Fig. 8 is a plan view of the circuit board 30. Fig. 9 is a bottom perspective view of the circuit board 30. Circuit board 30 is formed by cutting out a fan-shaped portion of a substantially circular board, and has a substantially L-shape. Circuit board 30 includes bottom surface 301, top surface 302, cutout portion 303, base portion 304, first extension portion 305, second extension portion 306, inspection switch 307, registration switch 308, deletion switch 309, antenna 310, conductor 311, control circuit 312 (not shown), wireless communication circuit 313 (not shown), insertion holes 314A and 314B, and heat detection units 315A and 315B.

[0032] The bottom surface 301 is the surface facing the mid-plate 50 .

[0033] The upper surface 302 is the surface facing the main body 21 .

[0034] The cutout 303 is a sector-shaped cutout with a central angle of approximately a right angle. The cutout 303 is an area where the battery housing 213 of the main body 21 and the speaker 40 are arranged.

[0035] The base 304 is a generally rectangular portion.

[0036] The first extending portion 305 is a portion extending from one end of the base portion 304. The first extending portion 305 has an inner edge portion 3051 and an outer edge portion 3052. The inner edge portion 3051 is a linear edge portion facing the cutout portion 303. The outer edge portion 3052 is an edge portion other than the inner edge portion 3051. The outer edge portion 3052 is an arc-shaped edge portion that includes a linear portion in part.

[0037] The second extension portion 306 is a portion extending from the other end of the base portion 304. The second extension portion 306 forms a substantially right angle with the first extension portion 305, sandwiching the cutout portion 303 therebetween. The second extension portion 306 has an inner edge portion 3061 and an outer edge portion 3062. The inner edge portion 3061 is a substantially linear edge portion facing the cutout portion 303. The outer edge portion 3062 is an edge portion other than the inner edge portion 3061. The outer edge portion 3062 is an arc-shaped edge portion that includes a linear portion in part.

[0038] The speaker 40 is connected to the tip side of the inner edge portion 3061 of the second extending portion 306. The speaker 40 has a disk shape.

[0039] The base portion 304, the first extension portion 305, and the second extension portion 306 are integrally provided.

[0040] When the inspection switch 307 is pressed, an internal circuit (fire detection unit, etc.) test and a battery life test are performed, and the results are reported by an LED (not shown). The inspection switch 307 is installed on the bottom surface 301 of the circuit board 30, near the rear end of the second extension portion 306.

[0041] The registration switch 308 is a switch used to set the wireless channel used by the heat detector 1. The registration switch 308 is provided on the upper surface 302 of the circuit board 30. The registration switch 308 is provided on the rear end side of the first extension portion 305.

[0042] The erase switch 309 is a switch used to erase the setting of the wireless channel in the heat detector 1. The erase switch 309 is provided on the upper surface 302 of the circuit board 30. The erase switch 309 is provided on the rear end side of the first extension portion 305.

[0043] The antenna 310 is a metal wire. One end of the antenna 310 is connected to the wireless communication circuit 313, and the antenna 310 extends along the inner wall of the cover 22 from the outer edge 3052 of the first extension portion 305 to the outer edge 3062 of the second extension portion 306 in a bottom view.

[0044] Antenna 310 includes a straight portion 3101 and an arc portion 3102. One end of straight portion 3101 is connected to wireless communication circuit 313, extends substantially vertically from bottom surface 301 of circuit board 30, and is inserted into antenna hole 509 (see FIG. 16 ) formed in middle plate 50. One end of arc portion 3102 is connected to the other end of straight portion 3101, and extends from outer edge 3052 of first extension portion 305 to outer edge 3062 of second extension portion 306 along the inner wall of cover 22 in bottom view.

[0045] Antenna 310 is connected to one end of circuit board 30, which has a substantially L-shape when viewed from the bottom, and extends so as not to surround notch 303.

[0046] The conductor 311 is a metal wire. One end of the conductor 311 is connected to a ground (not shown) on the circuit board 30, and extends from an inner edge 3061 of the second extension portion 306, through the cutout portion 303, along the inner wall of the cover 22, to an outer edge 3062 of the second extension portion 306, in a bottom view.

[0047] The conductor 311 includes a straight portion 3111 and an arc portion 3112. One end of the straight portion 3111 is connected to a ground (not shown) on the circuit board 30, and extends from an inner edge portion 3061 of the second extension portion 306 to pass through the cutout portion 303 in a bottom view. One end of the arc portion 3112 is connected to the other end of the straight portion 3111, and extends along the inner wall of the cover 22 to an outer edge portion 3062 of the second extension portion 306 in a bottom view.

[0048] Conductor 311 is connected to the other end of circuit board 30, which has a substantially L-shape in bottom view, and extends to surround speaker 40 while not surrounding battery accommodating section 213 of main body 21 (in other words, the battery).

[0049] By increasing the length of the ground with conductor 311, the gain of antenna 310 is improved compared to when conductor 311 is not provided. In addition, conductor 311 is wired so as not to surround the battery when viewed from the bottom, which further improves the gain of antenna 310.

[0050] The control circuit 312 includes a CPU, a ROM, a RAM, etc. The CPU executes a control program stored in the ROM to perform fire detection processing, fire signal transfer processing, and wireless channel setting processing, which will be described later.

[0051] The wireless communication circuit 313 transmits and receives wireless signals to and from other heat detectors 1 and relay devices via the antenna 310.

[0052] Insertion holes 314A and 314B are each a substantially rectangular through-hole, and heat detection unit 315A is inserted obliquely into insertion hole 314A, and heat detection unit 315B is inserted obliquely into insertion hole 314B. Insertion hole 314A is formed in base portion 304, and insertion hole 314B is formed in second extension portion 306. In the following description, unless there is a particular need to distinguish between them, insertion holes 314A and 314B will be collectively referred to as "insertion holes 314," and heat detection units 315A and 315B will be collectively referred to as "heat detection units 315."

[0053] FIG. 10 is a diagram showing the external appearance of the heat detection unit 315. As shown in FIG. Heat detection unit 315 includes rod-shaped lead portion 3151 made of a lead wire, a substantially spherical heat-sensing portion 3152 connected to one end of lead portion 3151, a substantially rectangular parallelepiped base portion 3153 connected to the other end of lead portion 3151, and two pins 3154 extending from base portion 3153. Heat-sensing portion 3152 included in heat detection unit 315 is a temperature detection element such as a thermistor.

[0054] 11 to 15 are enlarged views of the vicinity of the insertion hole 314. FIG. Fig. 11 is an enlarged view of the vicinity of the insertion hole 314 shown in Fig. 7. Fig. 12 is an enlarged view of the vicinity of the insertion hole 314 shown in Fig. 8. Fig. 13 is a cross-sectional view taken along line BB in Fig. 12. Fig. 14 is an enlarged view of the vicinity of the insertion hole 314 shown in Fig. 8 with the heat detection unit 315 removed. Fig. 15 is a cross-sectional view taken along line CC in Fig. 14. The insertion hole 314 has an opening 3141 and notches 3142A and 3142B.

[0055] The opening 3141 is a rectangular through-hole having a size that allows the heat detection unit 315 to pass through. The base 3153 and pin 3154 of the heat detection unit 315 are inserted into the opening 3141.

[0056] The notches 3142A and 3142B are U-shaped notches formed side by side on the edge of the opening 3141. The notches 3142A and 3142B are formed to extend approximately parallel to the width direction of the opening 3141. A pin 3154 is inserted into the notches 3142A and 3142B. By using the insertion hole 314 having these openings 3141 and notches 3142A and 3142B, the heat detection unit 315 can be attached at an angle even if it is not at the end of the circuit board 30 (for example, even near the center).

[0057] Here, the inclination angle θ of the heat detection unit 315 relative to the circuit board 30 (see FIG. 13) is determined taking into consideration the balance between the heat receiving characteristics required of the heat sensing unit 3152 and the thickness of the heat detector 1. The heat receiving characteristics of the heat sensing unit 3152 improve as the inclination angle θ increases (in other words, the greater the distance between the heat sensing unit 3152 and the circuit board 30). On the other hand, the thickness of the heat detector 1 decreases as the inclination angle θ decreases (in other words, the closer the distance between the heat sensing unit 3152 and the circuit board 30). Taking these factors into consideration, the inclination angle θ is set, for example, in the range of 5 degrees to 60 degrees. The heat receiving characteristic here refers to the difference between the temperature detected by the heat sensing part 3152 and the actual temperature of the surroundings, and the better the heat receiving characteristic, the smaller the temperature difference.

[0058] As shown in FIG. 12, a land 316 is arranged around the notch 3142A on the upper surface 302 of the circuit board 30 so as to surround the notch 3142A. The land 316 is a soldering portion having a substantially U-shape, and a pin 3154 of the heat detection unit 315 is soldered to the land 316. As shown in FIG. 14, the land 316 has a third portion 3161 and a fourth portion 3162 that face each other across the notch 3142A. The width W1 of the third portion 3161, which is closer to the adjacent land 317, is narrower than the width W2 of the fourth portion 3162. This is to prevent the occurrence of a solder bridge between the lands 316 and 317.

[0059] A thermal relief 318 is formed around the land 316 so as to surround a portion of the land 316. Here, as shown in FIG. 15, the thermal relief 318 is a narrow groove that separates the land 316 from the resist layer 327 around it. Furthermore, the land 316 is not connected to any circuit on the upper surface 302 of the circuit board 30. Therefore, during soldering, the heat applied to the land 316 is not easily diffused, making the soldering process easy.

[0060] Meanwhile, a land 317 is arranged around the notch 3142B on the upper surface 302 of the circuit board 30 so as to surround the notch 3142B. The land 317 is a soldering portion having a substantially U-shape, and the pin 3154 of the heat detection unit 315 is soldered to the land 317. As shown in FIG. 14 , the land 317 has a first portion 3171 and a second portion 3172 that face each other across the notch 3142B. The width W4 of the second portion 3172, which is closer to the adjacent land 316, is narrower than the width W3 of the first portion. This is to prevent the occurrence of a solder bridge between the lands 316 and 317.

[0061] A thermal relief 319 is formed around the land 317 so as to surround a portion of the land 317. Here, as shown in FIG. 15, the thermal relief 319 is a narrow groove that separates the land 317 from the resist layer 327 around it. Furthermore, the land 317 is not connected to any circuit on the upper surface 302 of the circuit board 30. Therefore, during soldering, the heat applied to the land 317 is not easily diffused, making the soldering process easy.

[0062] Next, on the bottom surface 301 of the circuit board 30, a generally U-shaped land 320 is arranged around the notch 3142B so as to surround the notch 3142B, as shown in FIG. 11. A thermal relief 321 is formed around the land 320 so as to surround a portion of the land 320. Here, as shown in FIG. 15, the thermal relief 321 is a narrow groove that separates the land 320 from the resist layer 328 around it. The portion of the land 320 that is not surrounded by the thermal relief 321 is connected to one of the circuits on the bottom surface 301 of the circuit board 30 via conductive wiring 322.

[0063] 15 , this land 320 is electrically connected to land 317 on the top surface 302 of circuit board 30 via three through holes 323. Here, through holes 323 are through holes formed in circuit board 30, and serve to electrically connect land 320 and land 317. Therefore, the output signal of heat detection unit 315 soldered to land 317 is transmitted to land 320 via through holes 323, and the output signal transmitted to land 320 is transmitted to the circuit on bottom surface 301 of circuit board 30 via wiring 322.

[0064] Note that, by connecting land 320 and land 317 via through-hole 323, both lands are less likely to peel off from circuit board 30. In particular, when an external force is applied to the tip of heat detection unit 315, it is expected that a force will be applied to land 317 in a direction that would cause it to peel off from circuit board 30, but even in such a case, peeling from circuit board 30 is suppressed. When the pin 3154 of the heat detection unit 315 is soldered to the land 317, the through-hole 323 is filled with solder, which also firmly bonds the land 317 and the land 320 to the circuit board 30. Therefore, these lands are prevented from peeling off from the circuit board 30.

[0065] Meanwhile, a substantially U-shaped land 324 is arranged around the cutout 3142A on the bottom surface 301 of the circuit board 30 so as to surround the cutout 3142A. A thermal relief 325 is formed around the land 324 so as to surround a portion of the land 324. Here, the thermal relief 325 is a thin groove that separates the land 324 from the resist layer 328 around it.

[0066] 15 , the land 324 is electrically connected to the land 316 on the upper surface 302 of the circuit board 30 via three through holes 326. Here, the through holes 326 are through holes formed in the circuit board 30, and are through holes for electrically connecting the land 324 and the land 316. The connection between the land 324 and the land 316 by the through holes 326 makes the lands less likely to peel off from the circuit board 30. In particular, when an external force is applied to the tip of the heat detection unit 315, it is expected that a force will be applied in a direction that would peel the land 316 from the circuit board 30, but even in such a case, peeling from the circuit board 30 is suppressed. When the pin 3154 of the heat detection unit 315 is soldered to the land 316, the through hole 326 is filled with solder, which also firmly bonds the land 316 and the land 324 to the circuit board 30. Therefore, these lands are prevented from peeling off from the circuit board 30. The above is the description of the circuit board 30.

[0067] Next, the intermediate plate 50 disposed below the circuit board 30 will be described. Fig. 16 is a bottom view of the mid-plate 50. Fig. 17 is a cross-sectional view taken along line AA in Fig. 1, and particularly shows only the mid-plate 50, the cover 22, and the heat detection unit 315. The middle plate 50 is formed by cutting out a portion of a substantially circular plate, and has a substantially U-shape. The middle plate 50 has a bottom surface 501, an upper surface 502 (see FIG. 4), a notch 503, a base 504, a first extension portion 505, a second extension portion 506, an insertion hole 507, a notch 508, an antenna hole 509, a speaker hole 510, a switch hole 511, and insertion holes 512 and 513.

[0068] The bottom surface 501 is the surface facing the cover 22 placed under the middle plate 50. The bottom surface 501 is formed flat, forming a flow space between it and the cover 22 (see FIG. 17). The bottom surface 501 is located on approximately the same plane as the upper edge 22111 of the air vent 2211 of the cover 22, making it easier for the horizontal airflow entering through the air vent 2211 to flow smoothly in parallel with the middle plate 50.

[0069] The upper surface 502 is the surface facing the circuit board 30 .

[0070] The cutout 503 is a substantially L-shaped cutout, and is an area where the battery accommodating section 213 of the main body 21 is disposed.

[0071] The base 504 is a generally semicircular portion.

[0072] The first extension portion 505 and the second extension portion 506 are portions that extend from the base portion 504. The first extension portion 505 and the second extension portion 506 extend substantially parallel to each other with the notch portion 503 therebetween.

[0073] The base portion 504, the first extension portion 505, and the second extension portion 506 are integrally provided.

[0074] The insertion hole 507 is a through-hole for inserting the antenna holding portion 217A of the main body 21. The antenna holding portion 217A inserted into the insertion hole 507 positions the antenna 310 on the bottom surface 501 of the middle plate 50.

[0075] The notch 508 is a through-hole for inserting the antenna holding portion 217B of the main body 21. The antenna holding portion 217B inserted into the notch 508 positions the antenna 310 on the bottom surface 501 of the middle plate 50.

[0076] By inserting antenna holding portion 217A into insertion hole 507 and inserting antenna holding portion 217B into notch 508, middle plate 50 is positioned relative to main body 21.

[0077] The antenna hole 509 is a through-hole for inserting the antenna 310. The antenna hole 509 is formed on the periphery of the second extension portion 506.

[0078] Fig. 18 is a bottom view of the heat detector 1 with the cover 22 removed. Fig. 19 is a bottom perspective view of the heat detector 1 with the cover 22 removed. Antenna 310 inserted through antenna hole 509 is wired along bottom surface 501 of middle plate 50. Antenna 310 is positioned by antenna holding portions 217A and 217B of main body 21 and push-in portion holding portion 218A.

[0079] Next, speaker hole 510 is formed in the center of first extension portion 505. Speaker hole 510 is formed so as to face speaker 40.

[0080] The switch hole 511 is a through-hole for inserting the inspection switch 307. The switch hole 511 is formed in the center of the base portion 504.

[0081] The insertion hole 512 is a through-hole through which the heat detection unit 315A is inserted obliquely. The insertion hole 512 is formed on one end side of the base 504, and has an opening 5121 and a notch 5122. The opening 5121 is a rectangular through-hole of a size that allows the heat detection unit 315 to pass through. The base 3153 and lead 3151 of the heat detection unit 315 are inserted into the opening 5121. On the other hand, the notch 5122 is an I-shaped notch, and is formed to extend approximately parallel to the length direction of the opening 5121. The lead 3151 is inserted into the notch 5122.

[0082] Heat-sensing portion 3152 of heat detection unit 315A inserted through insertion hole 512 faces flat portion R1 on bottom surface 501 in bottom view (see FIGS. 17 and 18). In addition, as described above, bottom surface 501 is formed flat and is located on approximately the same plane as upper edge portion 22111 of ventilation hole 2211 of cover 22. This allows the horizontal airflow flowing in from ventilation hole 2211 to flow smoothly through the circulation space, and the heat-receiving characteristics of heat detection unit 315A are better than when such a structure is not adopted.

[0083] The insertion hole 513 is a through-hole through which the heat detection unit 315B is inserted obliquely. The insertion hole 513 is formed on the other end side of the base 504, and has an opening 5131 and a notch 5132. The opening 5131 is a rectangular through-hole of a size that allows the heat detection unit 315 to pass through. The base 3153 and lead 3151 of the heat detection unit 315 are inserted into the opening 5131. On the other hand, the notch 5132 is an I-shaped notch, and is formed to extend approximately parallel to the length direction of the opening 5131. The lead 3151 is inserted into the notch 5132.

[0084] Heat-sensing part 3152 of heat detection unit 315B inserted through insertion hole 513 faces flat portion R2 on bottom surface 501 in bottom view (see FIGS. 17 and 18). In addition, as described above, bottom surface 501 is formed flat and is located on approximately the same plane as upper edge 22111 of ventilation hole 2211 of cover 22. This allows the horizontal airflow flowing in from ventilation hole 2211 to flow smoothly through the circulation space, and the heat-receiving characteristics of heat detection unit 315B are better than when such a structure is not adopted. The above is a description of the middle plate 50.

[0085] Here, a method for attaching the heat detection unit 315 to the circuit board 30 and the intermediate plate 50 will be described with reference to the drawings. Figures 20 to 23 are explanatory diagrams of this attachment method. Figures 20 to 22 are perspective views of the attachment method, and Figure 23 is a cross-sectional view taken along line DD in Figure 22. Note that hatching has been omitted in Figure 23 to make the drawing easier to read. Jig 2 is used to attach heat detection unit 315 to circuit board 30 and middle plate 50. Jig 2 is a roughly disk-shaped device that has a protrusion 201 for positioning middle plate 50 and a recess 202 for positioning heat detection unit 315.

[0086] As shown in FIG. 20 , the middle plate 50 is placed on the jig 2, and the circuit board 30 is placed on top of that. In this state, as shown in FIG. 21 , the heat detection unit 315A is inserted into the insertion hole 314A of the circuit board 30 and the insertion hole 512 of the middle plate 50. As shown in FIGS. 22 and 23 , the heat-sensing unit 3152 of the inserted heat detection unit 315A abuts against the bottom corner of the recess 202 of the jig 2. Furthermore, the pin 3154 is inserted through the notches 3142A and 3142B of the circuit board 30. As a result, the heat detection unit 315A is positioned. In this state, the worker solders the pin 3154 of the heat detection unit 315A to the lands 316 and 317 of the circuit board 30. At this time, since the heat detection unit 315A is positioned, the worker can perform the soldering work with both hands, making the work easier.

[0087] Meanwhile, heat detecting unit 315B is inserted through insertion hole 314B of circuit board 30 and insertion hole 513 of intermediate plate 50. The inserted heat detecting unit 315B is soldered to lands 316 and 317 of circuit board 30 in the same manner as heat detecting unit 315A.

[0088] 1-2.Operation The following describes the operation of the heat detector 1. Specifically, the following describes the fire detection process, the fire signal transfer process, and the wireless channel setting process.

[0089] 1-2-1. Fire detection processing When a fire breaks out in the area monitored by the heat detector 1, a vertical air current is generated from the source of the fire toward the ceiling. When the vertical air current reaches the ceiling, it changes direction and becomes a horizontal air current that flows parallel to the ceiling surface. Of the vertical and horizontal air currents, the vertical air current flows into the circulation space through the vertical hole 2221 in the cover 22 of the heat detector 1. On the other hand, the horizontal air current flows into the circulation space through the vent hole 2211 in the cover 22. The air current that flows into the circulation space transfers heat to the heat detection unit 315.

[0090] The control circuit 312 of the heat detector 1 periodically receives output values ​​from the heat detection unit 315 and determines whether the ambient temperature is equal to or higher than a predetermined temperature. When the vertical or horizontal airflow flows into the circulation space and the control circuit 312 determines that the ambient temperature is equal to or higher than a predetermined temperature, it causes the speaker 40 to emit an alarm sound and the wireless communication circuit 313 to transmit a fire signal to other heat detectors 1 and relay devices.

[0091] 1-2-2. Fire signal transfer processing When another heat detector 1 detects a fire and the fire signal transmitted from this heat detector 1 is received by the wireless communication circuit 313, the control circuit 312 causes an alarm sound to be emitted from the speaker 40 and also causes the wireless communication circuit 313 to transmit a fire signal to another heat detector 1 or a relay device.

[0092] 1-2-3. Wireless channel setting process When the user presses the push-in portion 216A of the main body 21 and presses and holds the registration switch 308, the control circuit 312 transitions to a wireless channel setting mode. Thereafter, the control circuit 312 changes the wireless channel each time the registration switch is pressed briefly. Each time the wireless channel is changed, the control circuit 312 causes the speaker 40 to emit a guide voice notifying the user of the wireless channel number. Then, when the registration switch 308 is pressed and held again, the control circuit 312 stores the number of the selected wireless channel and ends the wireless channel setting mode. The wireless channel number thus stored is erased when the user presses the push-in portion 216B of the main body 21 and presses the erase switch 309 for a long time.

[0093] In the heat detector 1 described above, the heat detecting unit 315 is attached at an angle to the circuit board 30. Therefore, the heat detector 1 can be made thinner than when the heat detecting unit 315 is attached perpendicular to the circuit board 30.

[0094] 2. Variations The above embodiment may be modified as follows: The modifications described below may be combined with each other.

[0095] 2-1. Variation 1 The shape of the housing 20 and the arrangement of its components are not limited to the illustrated example, and may be modified as appropriate within the scope of the invention described in the claims.

[0096] 2-2. Variation 2 The shape of the circuit board 30 and the arrangement of its components are not limited to the illustrated example, and may be modified as appropriate within the scope of the invention described in the claims.

[0097] For example, three or more insertion holes 314 may be formed. The shape and size of opening 3141 of insertion hole 314 may be changed as appropriate depending on the shape and size of base 3153 of heat detection unit 315 inserted through insertion hole 314. The number, shape, and size of notch 3142A or 3142B of insertion hole 314 may be changed as appropriate depending on the number, shape, and size of pins 3154 of heat detection unit 315 inserted through insertion hole 314. The number, shape, and size of lands 316 or 317 may be changed as appropriate depending on the number, shape, and size of pins 3154 of heat detection unit 315 inserted through insertion hole 314. The number of through holes 323 and 326 may be five or less, or seven or more.

[0098] 2-3. Variation 3 The number of pins 3154 of the heat detection unit 315 may be one or three or more. When the number of pins 3154 is one, the lead portion 3151 of the heat detection unit 315 may be connected directly to the pin 3154 without going through the base portion 3153.

[0099] 2-4. Variation 4 The shape of the intermediate plate 50 and the arrangement of its components are not limited to the illustrated example, and may be modified as appropriate within the scope of the invention described in the claims.

[0100] 2-5. Variation 5 The claimed invention may also be applied to non-wireless heat detectors. [Explanation of symbols]

[0101] REFERENCE SIGNS LIST 1...heat detector, 2...jig, 10...base, 20...casing, 21...main body, 22...cover, 30...circuit board, 40...speaker, 50...middle plate, 60...pressing portion, 61...shaft portion, 201...protruding portion, 202...recessed portion, 211...bottom surface, 212...top surface, 213...battery accommodating portion, 214...speaker accommodating portion, 215...circuit board accommodating portion, 216A, 216B...pressing portion, 217A, 217B...antenna holding portion, 218A, 218B...pressing portion holding portion, 221...cylindrical portion, 222 ...Bottom, 301...bottom surface, 302...top surface, 303...notch portion, 304...base portion, 305...first extension portion, 306...second extension portion, 307...inspection switch, 308...registration switch, 309...deletion switch, 310...antenna, 311...conductor, 312...control circuit, 313...wireless communication circuit, 314A, 314B...insertion hole, 315A, 315B...heat detection portion, 316, 317, 320, 324...lands, 318, 319, 321, 325...thermal relief, 322...wiring, 323, 326...through hole, 327, 328...resist layer, 501...bottom surface, 502...top surface, 503...notch, 504...base, 505...first extension portion, 506...second extension portion, 507...insertion hole, 508...notch, 509...antenna hole, 510...speaker hole, 511...switch hole, 512, 513...insertion hole, 2211...ventilation hole, 3051...inner edge portion, 3052...outer edge portion, 3061...inner edge portion, 3062...outer edge portion, 3101...straight line portion, 3102...arc portion, 3111...straight portion, 3112...arc portion, 3141...opening, 3142A, 3142B...notch, 3151...lead portion, 3152...thermosensitive portion, 3153...base, 3154...pin, 3161...third portion, 3162...fourth portion, 3171...first portion, 3172...second portion, 5121...opening, 5122...notch, 5131...opening, 5132...notch, 22111...upper edge, R1, R2...portion, W1 to W4...width

Claims

[Claim 1] A housing, a circuit board housed in the housing; a heat detection unit attached to the circuit board; a mid-plate housed in the housing and disposed below the circuit board; Equipped with The intermediate plate has an insertion hole through which the heat detection unit is inserted, the housing has a cover disposed under the midplate; The intermediate plate and the cover form a circulation space through which air flows, the cover comprises a bottom; Two vertical holes are formed on the periphery of the bottom portion so as to face each other, Each of the two vertical holes is a through hole, and allows a vertical airflow to flow into the flow space. A heat detector characterized by:

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