JP7329116B2 - Smoke detectors - Google Patents

Description

The present invention relates to a smoke sensor that senses smoke generated by fire or the like.

Conventionally, as a smoke sensor to detect smoke generated by a fire, etc., when smoke enters the smoke detection space, the light emitted from the light emitting part is scattered by the smoke and reaches the light receiving part. Photoelectric smoke detectors are known that detect Patent Literature 1 discloses a smoke sensor that is a chip component that is attached to a mounting surface such as a ceiling, and that has a light-emitting portion and a light-receiving portion surface-mounted on a substrate. In Patent Document 1, the substrate is provided in a direction perpendicular to the mounting surface.

Japanese Patent No. 5562097 (for example, FIG. 7)

However, in the smoke sensor disclosed in Patent Document 1, the board is attached in a direction perpendicular to the mounting surface, so the overall height of the smoke sensor increases. For this reason, miniaturization of the smoke sensor is desired.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a smoke sensor that can be made smaller.

The smoke sensor according to the present invention includes a housing mounted on a mounting surface and having a smoke detection space formed therein for detecting smoke, a light emitting unit for irradiating the smoke detecting space with light, and a light emitted from the light emitting unit. A smoke sensor comprising: a light receiving part for receiving light scattered in a smoke detection space; In the device, the housing has a body in which a wall forming the smoke detection space is formed, the light emitting part or the light receiving part is a chip component surface-mounted on the substrate, and the substrate has a wall around the wall A recessed notch is formed in accordance with the shape of the surface, and the wall is provided with a substrate on a part of the periphery .

According to the present invention, the substrate is provided horizontally on the mounting surface. Therefore, the height of the smoke sensor can be kept low. Therefore, the smoke sensor can be miniaturized.
Also, if the optical axis of the chip component is in the direction perpendicular to the substrate, the smoke detection space will increase in the height direction. The size of the smoke detector can be reduced without increasing the height of the space.

1 is an assembled perspective view showing smoke sensor 100 according to Embodiment 1 of the present invention. FIG. 1 is a top view showing smoke sensor 100 according to Embodiment 1 of the present invention. FIG. It is a side view showing smoke sensor 100 concerning Embodiment 1 of the present invention. 1 is an exploded perspective view showing smoke sensor 100 according to Embodiment 1 of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective sectional view which shows the smoke sensor 100 which concerns on Embodiment 1 of this invention. 1 is a top sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention; FIG. It is a side cross-sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention, and is a diagram showing light emitting portion 6A. It is a side sectional view showing smoke sensor 100 concerning Embodiment 1 of the present invention, and is a figure showing light sensing portion 6B. FIG. 7 is a top cross-sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention, and is an enlarged view of FIG. 6 . 4 is a top view showing substrate 6 of smoke sensor 100 according to Embodiment 1 of the present invention. FIG. FIG. 4 is a cross-sectional view schematically showing the positional relationship among the substrate 6, the smoke detection space 33, and the optical bench 4A in the smoke sensor 100 according to Embodiment 1 of the present invention;

Embodiment 1.
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a smoke sensor according to the present invention will be described with reference to the drawings. 1 is an assembled perspective view showing a smoke sensor according to Embodiment 1 of the present invention, FIG. 2 is a top view showing the smoke sensor according to Embodiment 1 of the present invention, and FIG. 1 is a side view showing a smoke sensor according to Embodiment 1 of the present invention; FIG. 4 is an exploded perspective view showing the smoke sensor according to Embodiment 1 of the present invention, FIG. 5 is a perspective sectional view showing the smoke sensor according to Embodiment 1 of the present invention, and FIG. 1 is a cross-sectional top view showing a smoke sensor according to Embodiment 1 of the present invention; FIG. FIG. 6 is a cross-sectional view taken along line AA of FIG.

As shown in FIGS. 1 to 6, the smoke sensor 100 is installed in a monitoring space such as a room of a house, for example, on a mounting surface such as a ceiling. The smoke sensor 100 also includes a housing 10 including a bottomed tubular first cover 11 and a base portion 12 provided on the back side of the first cover 11 . The smoke sensor 100 is housed in a housing 10, and includes a main body 3 that divides the space inside the housing 10 into upper and lower parts, a lid portion 4 provided in the main body 3, and an optical bench provided in the lid portion 4. It has a cover 5 and a labyrinth wall housed in the optical bench cover 5 and having a light shielding function. A smoke detection space 33 for detecting smoke is formed inside the housing 10, which will be described later in detail.

Furthermore, the smoke sensor 100 includes a substrate 6 provided between the main body 3 and the lid portion 4, a battery for supplying operating power to various circuits provided on the substrate 6, and a speaker for outputting voice and the like. 8. On the substrate 6, a light emitting part 6A for irradiating light into the smoke detecting space 33 for detecting smoke and a light receiving part 6B for receiving the light emitted from the light emitting part 6A and scattered in the smoke detecting space 33 are surface-mounted. ing.

A first cover 11 of the housing 10 is formed with an opening 1 extending in the circumferential direction. Two rows of openings 1 are formed in the vertical direction. The opening 1 communicates with the smoke passage inside the housing 10 . The first cover 11 includes a flat bottom surface portion 11A having an opening 11A1 for a push button, a cylindrical side surface portion 11B, and an annular corner connecting the bottom surface portion 11A and the side surface portion 11B. 11C. Further, the lower surface portion 11A faces the main body 3. As shown in FIG.

A base portion 12 of the housing 10 is provided above the first cover 11 . The smoke detector 100 can be fixed to the mounting surface by fixing the base portion 12 to the mounting surface, such as the ceiling surface or the wall surface, using screws or the like. The main body 3 includes a wall portion 3A inside which a smoke detecting space 33 into which smoke from the smoke passage flows is formed, and an upper surface portion 3B to which the upper end of the wall portion 3A is connected. The main body 3 has an opening on the side of the base portion 12 so that the battery can be inserted, and has a recessed battery housing portion 3C for housing the battery, and a recessed speaker housing portion formed by an annular wall in which the speaker 8 is housed. Part 3D.
Further, in FIG. 4, a printed circuit board setting portion 3P is provided on the left side of the speaker housing portion 3D. The printed circuit board installation portion 3P is a wall having a predetermined height, similar to the partition wall 3E2 described later, and is formed in a substantially U-shape according to the shape of the circuit board 6. The mounting surface side is stored. The board 6 is installed on the printed board installation portion 3P and the partition wall 3E2. The height of the wall of the printed circuit board installation portion 3P is such that a shield case 6F, which will be described later, can be accommodated.

A substrate 6 is provided on a part of the periphery of the wall portion 3A. The wall portion 3A includes a wall portion a, a wall portion b, a wall portion c, and a wall portion d. The wall a is connected to one end of the wall c and one end of the wall d. The wall b is connected to the other end of the wall c and the other end of the wall d. A first hole 31 through which light emitted from the light emitting unit 6A passes is formed in the wall c, and a second hole 32 through which light received by the light receiving unit 6B passes is formed in the wall d. ing. Further, the wall portion 3A is provided with a pair of projecting portions 34 as light shielding columns for preventing the straight light from the light emitting portion 6A from entering the light receiving portion 6B.

The main body 3 has a partition wall 3E1 that partitions the side on which the battery is arranged and the side on which the substrate 6 is provided. In other words, the substrate 6 is provided on the upper surface portion 3B side of the main body 3, and the battery is provided on the back side thereof. The main body 3 also has a partition wall 3E2 connected to the wall portion 3A. A substrate 6 (a portion of the substrate having the light emitting portion) is provided directly below the lower end of the partition wall 3E2. The partition wall 3E2 has a function of blocking light from the light emitting portion 6A. Here, the partition wall 3E2 and the substrate 6 are separate bodies. Therefore, a gap is formed between the lower end of the partition wall 3E2 and the mounting surface 6a, which is the upper surface of the substrate 6. As shown in FIG. The smoke sensor 100 has a light shielding part 30 having a light shielding function so that the light from the light emitting part 6A does not leak through the gap.

The light shielding part 30 is a plate-shaped member extending in the vertical direction. That is, the light blocking portion 30 extends to the lower side of the slit 6E. That is, when the substrate 6 is mounted on the partition wall 3E2 of the main body 3, the light shielding portion 30 has a height that allows the lower end of the light shielding portion 30 to slightly protrude from the lower surface (back surface 6b) of the substrate 6. . Therefore, even if an attempt is made to see the light emitting portion 6A through the gap between the lower end of the partition wall 3E2 and the mounting surface 6a, which is the upper surface of the substrate 6, the light emitting portion 6A is hidden by the light shielding portion 30. FIG. By providing the light blocking portion 30 in this manner, light from the light emitting portion 6A to the light receiving portion 6B can be blocked outside the wall portion 3A. In addition, the light from the light emitting section 6A is prevented from leaking from the gap between the lower end of the partition wall 3E2 and the mounting surface 6a, which is the top surface of the substrate 6, to the light receiving section 6B side.

A plate-shaped member, for example, can be adopted as the light shielding portion 30 . The light shielding part 30 is formed so as to protrude from the smoke detection space 33 side toward the substrate 6 side. The light shielding section 30 is provided side by side with the light emitting section 6A. That is, the distance from the light shielding section 30 to the light emitting section 6A is shorter than the distance from the light shielding section 30 to the light receiving section 6B. Further, the light blocking portion 30 is connected to the wall portion 3A so that the light from the light emitting portion 6A does not leak from the boundary between the light blocking portion 30 and the wall portion 3A. In addition, the light shielding portion 30 is connected to the connecting portion between the wall portion b and the wall portion c. The light blocking portion 30 extends parallel to, for example, the optical axis of the light emitting portion 6A.

The lid portion 4 includes an optical bench 4A provided with an optical bench cover 5, and a through hole 4B formed in the optical bench 4A. An optical bench cover 5 and a labyrinth wall are provided below the optical bench 4A. A smoke detection space 33, a substrate 6, and a wall portion 3A are provided above the optical bench 4A (see FIG. 11). The through hole 4</b>B communicates the space inside the optical bench cover 5 with the smoke detection space 33 . Further, the lid portion 4 includes a wall accommodation portion 4C that accommodates the wall portion 3A and the like. The wall housing portion 4C is formed so that its inner side is one size larger than the wall portion 3A and the like, and is provided around the wall portion 3A and the like. The optical bench cover 5 is a flat member. A cylindrical insect screen is provided on the top of the optical bench cover 5 . The insect screen has a plurality of holes through which smoke passes. A labyrinth wall is housed inside the optical bench cover 5 and the insect screen.

The substrate 6 is provided horizontally in parallel with a mounting surface such as a ceiling surface. The base portion 12 is attached horizontally to the mounting surface, and the main body 3 is attached so as to be horizontal with the base portion 12 . The substrate 6 is attached so as to be horizontal with the main body 3 . Therefore, the substrate 6 is provided horizontally parallel to the mounting surface. Further, the substrate 6 has an optical system arrangement portion 6C in which the light emitting portion 6A and the light receiving portion 6B are arranged. The optical system arrangement portion 6C is a recessed notch portion formed in accordance with the peripheral shape of the wall portion 3A. The optical system arrangement portion 6C is provided around the wall portion 3A. Specifically, the optical system arrangement portion 6C is provided on the outer peripheral surface of the wall portion b, the outer peripheral surface of the wall portion c, and the outer peripheral surface of the wall portion d. The optical system arranging portion 6C includes a light emitting portion arranging portion 6D1 in which the light emitting portion 6A is arranged, and a light receiving portion arranging portion 6D2 in which the light receiving portion 6B is arranged (see FIG. 9). A slit 6E into which the light shielding portion 30 is inserted is formed in the substrate 6 (see FIG. 10). The slit 6</b>E has a shape that matches the horizontal cross-sectional shape of the light shielding portion 30 . On the substrate 6, an amplifier circuit for amplifying the signal detected by the light receiving section 6B and a control device (not shown) such as a microcomputer for controlling the operation of the light emitting section 6A and the light receiving section 6B are provided on the side of the light receiving section 6B. is provided in

The light emitting section 6A can be configured by, for example, an LED. Further, the light receiving section 6B can be composed of, for example, a photodiode. The light emitting section 6A and the light receiving section 6B are mounted on the mounting surface 6a of the substrate 6. As shown in FIG. In other words, the light emitting section 6A and the light receiving section 6B are chip parts without lead wires. More specifically, the light-emitting portion 6A includes a chip-type LED, and the light-receiving portion 6B includes a chip-type photodiode. As a result, the substrate 6 can be made thinner. At least one of the light-emitting portion 6A and the light-receiving portion 6B may be a chip component. More specifically, the light-emitting portion 6A and the light-receiving portion 6B, which are chip parts, do not have lead wires and are directly installed on the substrate 6, so that the protrusion height from the substrate 6 is low. Since the height of the chip component itself is substantially the same as the thickness of the substrate 6, the size of the optical system comprising the pair of light emitting element and light receiving element of the smoke sensor can be reduced.
The light-emitting portion 6A and the light-receiving portion 6B are chip components surface-mounted on the substrate, and the optical axes of these chip components are parallel to the mounting surface 6a of the substrate 6. FIG. A smoke detection space 33 exists in front of the light emitting portion 6A through the first hole portion 31. As shown in FIG. In other words, as shown in FIG. 11, the smoke detection space 33 and the optical system are provided on substantially the same plane and have the same relationship in height direction. The height of the wall portion 3A is the height of the smoke detection space 33, but when the substrate 6 is installed in the printed substrate installation portion 3P, the height from the upper surface portion 3B of the main body 3 to the back surface 6b of the substrate 6 is It is formed slightly lower than the height of the smoke space 33 .

The smoke sensor 100 includes a shield case 6F having a function of preventing noise from being detected by the light receiving section 6B. The shield case 6F is fixed on the substrate 6. As shown in FIG. The shield case 6F covers and protects the light receiving section 6B, the amplifier circuit and the control device. The shield case 6F has a rectangular parallelepiped box shape and can be manufactured by bending sheet metal, so that it is easy to assemble.

Referring to FIG. 8, the shield case 6F is provided so as to partially cover the substrate 6. As shown in FIG. The shield case 6F has, for example, a box shape with one side open. The shield case 6F includes a top surface portion 6F1 provided above the light receiving portion 6B, and a front surface portion 6F2 having a circular through hole 6F3. The top surface portion 6F1 faces the mounting surface 6a of the substrate 6. As shown in FIG. The front portion 6F2 is provided between the light receiving portion 6B and the wall portion d. The center of the second hole portion 32 and the center of the through hole 6F3 are aligned. The upper end of the front surface portion 6F2 is connected to the top surface portion 6F1. A lower end 6F4 of the front portion 6F2 extends below the surface of the substrate 6 on which the light receiving portion 6B is provided. That is, the lower end 6F4 of the front portion 6F2 extends below the mounting surface 6a. A lower end 6F4 of the front portion 6F2 extends to the mounting surface 6a of the substrate 6, for example, the back surface 6b.

FIG. 7 is a side cross-sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention, and shows light emitting portion 6A. 7 is a cross-sectional view taken along the line BB of FIG. 6. FIG. As shown in FIG. 7, the light emitting section 6A is a chip component provided on the outer edge of the substrate 6. As shown in FIG. Further, as shown in FIGS. 6 and 7, a light emitting notch 40 is formed in the substrate 6 below the light emitting portion 6A. When there is a substrate 6 without a notch directly below the light emitting portion 6A provided at the outer edge of the substrate 6, the light emitted downward from the light emitting portion 6A is irregularly reflected on the substrate 6, and the traveling direction of the light is not determined. do not have. On the other hand, in Embodiment 1, since the light emitting notch 40 is formed below the light emitting part 6A, the light emitted downward from the light emitting part 6A is not irregularly reflected by the substrate 6, and the light emitting notch 40 Continue downwards through the Therefore, unnecessary irregular reflection of light can be suppressed. The light-emitting portion 6A, which is a chip component, is composed of a body portion installed on the substrate and a light-emitting body provided in front of the body portion for emitting light. It is made equal to or slightly larger than the width of the emitter. Although the light emitting part 6A is installed on the outer edge of the substrate 6, more specifically, as shown in FIGS. .

FIG. 8 is a side sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention, and shows light receiving portion 6B. 8 is a cross-sectional view taken along line CC of FIG. 6. FIG. As shown in FIG. 8, the light receiving section 6B is a chip component provided on the outer edge of the substrate 6. As shown in FIG. As shown in FIGS. 6 and 8, a light receiving notch 41 is formed in the substrate 6 in front of and below the light receiving portion 6B. Here, the shield case 6F covers the light receiving section 6B, the control device and the amplifier circuit, and the end on the side of the light receiving section 6B is inserted into the light receiving notch 41. As shown in FIG. By extending the tip of the shield case 6F on the side of the light receiving portion 6B in this manner, an area for forming the through hole 6F3 can be secured.

FIG. 9 is a top sectional view showing smoke sensor 100 according to Embodiment 1 of the present invention, and is an enlarged view of FIG. FIG. 10 is a top view showing substrate 6 of smoke sensor 100 according to Embodiment 1 of the present invention. As described above, the substrate 6 is formed with the light emitting notch 40 and the light receiving notch 41 as shown in FIGS. In FIG. 10, for the sake of convenience, the positions where the light-emitting portion 6A and the light-receiving portion 6B are arranged are indicated by dotted lines. Here, the substrate 6 will be described with reference to FIG. The substrate 6 is formed in a substantially rectangular shape, and one end of the long piece thereof is formed with a large notch to serve as an optical system arrangement portion 6C. This notch is formed in a substantially trapezoidal shape with a long outer side, and has a shape corresponding to the shape of the wall portion 3A. More specifically, the notch portion of the substrate 6 is shaped so that the protruding portion 34 serving as the light shielding column in the wall portion 3A is engaged. The notch of the substrate 6 is further provided with a light emitting notch 40, a light receiving notch 41, and a slit 6E toward the inner side of the substrate 6. As shown in FIG.

Next, the operation of smoke sensor 100 will be described. When a fire or the like occurs, smoke flows into the smoke passage through the opening 1 of the housing 10 . The smoke flowing into the smoke passage flows into the space inside the optical bench 4A through the holes of the insect screen in the optical bench cover 5. FIG. The smoke that has flowed into the space inside the optical bench 4A flows into the through hole 4B of the lid 4 after passing through the labyrinth wall. The smoke that has flowed into the through hole 4B flows into the smoke detection space 33 . The smoke contains fine particles. These particles are heavier than smoke, so they are less likely to rise. Therefore, the particles remain on the optical bench 4A, and only the smoke flows into the smoke detection space 33. As a result, the smoke sensor 100 can improve the fire detection accuracy.

The light emitting section 6A emits light into the smoke detection space 33 through the first hole 31 . Here, most of the light emitted from the light emitting section 6A enters the smoke detection space 33. As shown in FIG. However, part of the light emitted from the light emitting section 6A travels away from the optical axis of the light emitting section 6A and does not enter the smoke detection space 33 . Light that has not entered the smoke detection space 33 is blocked by the light shielding part 30, and leakage of light that has not entered the smoke detection space 33 through the gap between the partition wall 3E2 and the substrate 6 is suppressed. When smoke flows into the smoke detection space 33, the light emitted from the light emitting section 6A is scattered by the smoke. The smoke detector 100 senses a fire by detecting this scattered light with the light receiving section 6B.

According to the first embodiment, the substrate 6 is provided horizontally with respect to the mounting surface. Therefore, the height of the smoke sensor 100 can be kept low. In addition, as the optical system (light-emitting portion 6A, light-receiving portion 6B) provided on the substrate 6, chip components without lead wires extending in the height direction of the smoke sensor 100 are used. The system protrudes very little from the surface of the substrate 6 . Therefore, the smoke sensor 100 can be made thinner. The light-emitting portion 6A is a chip component provided on the outer edge of the substrate 6, and a light-emitting notch 40 is formed in the substrate 6 below the light-emitting portion 6A. If there is a substrate 6 without a notch directly below the light emitting portion 6A, the light emitted downward from the light emitting portion 6A is irregularly reflected on the substrate 6, and the traveling direction of the light is not fixed. On the other hand, in Embodiment 1, since the light emitting notch 40 is formed below the light emitting portion 6A, the light emitted downward from the light emitting portion 6A is not irregularly reflected by the substrate 6 and travels downward as it is. do. Therefore, the light is not blocked, and unnecessary irregular reflection of the light can be suppressed. As a result, in the optical system having the surface-mounted light-emitting portion 6A, it is possible to sufficiently secure signal components while suppressing noise components of the light-receiving portion 6B when detecting smoke. Therefore, the S/N ratio required for smoke detection can be obtained. Since the conventional light-emitting element is a DIP part having lead wires, it was not necessary to consider diffused reflection because the distance between the light-emitting element and the substrate is long. By providing 40, the problem of diffused reflection can be solved.

In order to detect smoke with high accuracy, it is preferable to match the height position of the light emitting portion 6A and the height position of the light receiving portion 6B. The optical axis of the light-emitting portion 6A and the optical axis of the light-receiving portion 6B, which extend in the horizontal direction, do not necessarily have to have the same height. It is desirable to Therefore, when the light-emitting section 6A is a chip component, the light-receiving section 6B must be lowered as much as the position of the light-emitting section 6A is lowered. When lowering the position of the light receiving portion 6B, it is necessary to lower the height position of the second hole portion 32 and the height position of the through hole 6F3 in accordance with the height position of the light receiving portion 6B. Here, if the lower end 6F4 of the front portion 6F2 of the shield case 6F is above the mounting surface 6a of the substrate 6, the front portion 6F2 may be deformed when the through holes 6F3 are formed in the front portion 6F2. be. Further, if the lower end 6F4 of the front portion 6F2 of the shield case 6F is above the mounting surface 6a, there is a possibility that the through hole 6F3 cannot be formed in the front portion 6F2. If the front portion 6F2 is deformed or the shape of the through hole 6F3 is deformed, the light receiving characteristics of the light receiving portion 6B change, and the smoke sensor 100 cannot accurately detect smoke.

A lower end 6F4 of the front portion 6F2 of the shield case 6F of the smoke sensor 100 according to the first embodiment extends below the surface of the substrate 6 on which the light receiving portion 6B is provided. Therefore, it is possible to suppress deformation of the front portion 6F2 when forming the through hole 6F3 in the front portion 6F2. Moreover, the shape of the through-hole 6F3 can be more reliably set to a predetermined shape, such as a circular shape. The horizontally extending optical axis of the light receiving portion 6B and the height of the through hole 6F3 provided in the shield case 6F are at the same height position. Since the shield case 6F having the through hole 6F3 can be provided in front of the light receiving section 6B in this way, the light receiving section 6B can be protected from noise, so that the smoke sensor 100 can reduce the smoke detection accuracy. can be suppressed. Even if either the light emitting unit 6A or the light receiving unit 6B is not a chip part, the smoke sensor 100 can obtain the effect of suppressing the deterioration of the smoke detection accuracy. If the part 6B is a chip component, the effect is further enhanced.

The lower end 6F4 of the front portion 6F2 of the shield case 6F extends below the surface of the substrate 6 on which the light receiving portion 6B is provided, that is, extends below the mounting surface 6a. The lower end 6F4 has a length that extends to around the back surface 6b of the substrate 6. As shown in FIG. Therefore, even if the noise light that could not be blocked by the light blocking portion 30 enters the light receiving portion 6B side through the gap between the partition wall 3E2 and the substrate 6, the noise light is detected by the light receiving portion 6B. can be further suppressed.
Since conventional light receiving elements are DIP parts with lead wires, the distance between the light receiving element and the substrate is long, so it was possible to freely form a through hole for the light receiving element in the shield case installed in front. By providing the light-receiving notch 41 when directly placing the light-receiving part 6B on top, the length (height) of the shield case on the front side can be secured, and a through-hole for the light-receiving element can be formed without problems. .
By the way, since the amount of light received by the light receiving section 6B is inversely proportional to the square of the distance, the amount of light received is greatest at positions near the end face of the substrate 6 in the space surrounded by the shield case 6F and the substrate 6. In terms of increasing the amount of received light scattered by smoke, it is desirable to install the light receiving section 6B at the outer edge of the substrate 6 . On the other hand, it is necessary to provide a shield case 6F in front of the light receiving section 6B. Therefore, in this embodiment, a light-receiving notch 41 is provided in front of the portion where the light-receiving part 6B is installed in the substrate 6, and the front part 6F2 of the shield case bent from the top surface part 6F1 is passed through the light-receiving notch 41. I made it The width of the front portion 6F2 is slightly smaller than the width of the light receiving cutout 41, so that the front portion 6F2 can be inserted into the light receiving cutout 41. FIG. By doing so, the light receiving section 6B can be installed on the outer edge of the substrate 6, and the shield case 6F can be provided in front of the light receiving section 6B without requiring extra space. The width of the light-receiving notch 41 can be changed appropriately, but it has a shape wider than the width of the light-emitting notch 40 .

As described above, the amount of light received by the light receiving section 6B is inversely proportional to the square of the distance. There are many. In the first embodiment, since the light receiving portion 6B is arranged inside the end face of the substrate 6, the shield case 6F is prevented from colliding with the light receiving portion 6B during assembly, thereby preventing the lens portion of the light receiving portion 6B from being damaged. can be suppressed. Furthermore, since the board 6 is not cut out directly below the shield case 6F, the shielding effect of the board 6 is maximized, and stray light from the light emitting section 6A does not enter, thereby suppressing noise components. .

An amplifier circuit and the like are provided around the light receiving section 6B. Therefore, the number of wirings around the light receiving section 6B is larger than the number of wirings around the light emitting section 6A. When the light shielding portion 30 is provided side by side with the light receiving portion 6B, it is necessary to form the slit 6E around the light receiving portion 6B. Therefore, if the light shielding section 30 is installed side by side with the light receiving section 6B, the length of the wiring around the light receiving section 6B is increased or the wiring pattern is complicated by the amount of bypassing the slit 6E. The light shielding portion 30 of the substrate 6 of the smoke sensor 100 according to the embodiment is provided side by side with the light emitting portion 6A. Therefore, the smoke sensor 100 can prevent the wiring length around the light receiving section 6B from becoming long and the wiring pattern from becoming complicated.
In the present embodiment, a type of smoke detector generally called a fire alarm equipped with a battery and a speaker has been described as an example. can be applied.

1 opening, 3 main body, 3A wall, 3B upper surface, 3C battery housing, 3D speaker housing, 3E1 partition wall, 3E2 partition wall, 4 lid, 4A optical bench, 4B through hole, 4C wall housing , 5 optical bench cover, 6 substrate, 6A light emitting part, 6B light receiving part, 6C optical system arrangement part, 6D1 light emitting part arrangement part, 6D2 light receiving part arrangement part, 6E slit, 6F shield case, 6F1 top surface part, 6F2 front part, 6F3 through hole 6F4 lower end 6a mounting surface 6b back surface 8 speaker 10 housing 11 first cover 11A lower surface portion 11A1 opening for push button 11B side surface portion 11C corner portion 12 base portion 30 light shielding part 31 first hole 32 second hole 33 smoke detection space 34 protrusion 40 light emitting notch 41 light receiving notch 100 smoke sensor a wall b wall c wall, d wall.

Claims (5)

a housing attached to the mounting surface and having a smoke detection space formed therein for detecting smoke;
a light emitting unit that irradiates the smoke detection space with light;
a light receiving unit that receives the light emitted from the light emitting unit and scattered in the smoke detection space;
A smoke sensor comprising a substrate provided inside the housing so as to be horizontal to the mounting surface, and on which the light emitting unit and the light receiving unit are mounted,
The housing comprises a main body in which a wall forming the smoke detection space is formed,
The light emitting unit or the light receiving unit is a chip component surface-mounted on a substrate,
A recessed notch is formed in the substrate according to the shape of the peripheral surface of the wall,
A substrate is provided on a part of the periphery of the wall.
A smoke detector characterized by : the wall portion is composed of four wall portions that are connected to each other;
a wall portion formed with a first hole through which the light emitted from the light emitting portion passes;
a wall portion formed with a second hole through which the light received by the light receiving portion passes;
A smoke sensor according to claim 1, characterized in that: A wall portion forming the smoke detection space is not provided on the substrate, but is provided at the same height position as the substrate, and the wall portion is sandwiched between a light emitting portion and a light receiving portion mounted on the substrate. provided so that
3. The smoke sensor according to claim 2, characterized in that: The recessed notch formed in the substrate is formed in a substantially trapezoidal shape with a long outer side and has a shape corresponding to the shape of the wall.
3. The smoke sensor according to claim 2, characterized in that: The light emitting unit is the chip component provided on the outer edge of the substrate,
A light-emitting notch is formed below the light-emitting body of the light-emitting portion in the substrate.
A smoke sensor according to claim 1, characterized in that:

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