Heat sensor

Abstract

To provide a heat sensor of which the installation work is facilitated by making an indicator lamp, which is lighted while the sensor is actuated, visible in any direction.SOLUTION: A heat sensor 100 comprises: a case body 10 storing a substrate 20 on which a sensor 40 sensing heat and a light source 50 are mounted therein and including an opening 11 on a bottom face; a case lid 30 which is disposed in the opening 11 of the case body 10; and a cover part 64 which is disposed at a lower side of the case body 10 and the case lid 30 so as to cover the opening 11 and in which a hole part (a third hole part 64a) is provided in the center. The case lid 30 includes a central part 30c, and a sensor hole part (a first hole part 31) which is disposed in the central part 30c and through which the sensor 40 is inserted, and the cover part 64 is disposed while exposing the central part 30c of the case lid 30 from the hole part (the third hole part 64a). In the heat sensor 100, light from the light source 50 is emitted through the central part 30c to the outside.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a heat sensor including a light source.

Background Art

[0002] Conventionally, a heat sensor includes a sensor composed of a thermistor or the like that detects heat, and senses the occurrence of a fire by detecting the heat of a hot air flow generated by the fire. In the heat sensor, a substrate is disposed in a case (sensor main body), and the sensor is attached to the substrate such that a heat-sensitive portion is exposed through an air flow inlet provided at the center of the lower surface of the sensor main body. In such a heat sensor, there is one provided with an indicator light such as an LED (Light Emitting Diode) connected to the substrate, and the indicator light is lit when a fire occurs (see, for example, Patent Document 1). In the heat sensor of Patent Document 1, one indicator light is connected to the substrate and incorporated in an indicator window member provided on the outer peripheral side on the lower surface of the sensor main body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the heat sensor of Patent Document 1, only one indicator light is used, and since the indicator light is provided on the outer peripheral side on the lower surface of the sensor main body, when installing, there is a hassle of adjusting the orientation of the heat sensor so that the indicator light can be seen from the entrance of the monitoring space.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a heat sensor that facilitates the installation work by enabling the indicator light that lights up when the sensor operates to be visible from any direction.

Means for Solving the Problems

[0006] The thermal sensor of the present invention includes a case body that houses a substrate on which a sensor for sensing heat and a light source are mounted, the case body having an opening on its lower surface, a case lid disposed at the opening of the case body, and a cover portion disposed below the case body and the case lid so as to cover the opening and having a hole provided at its center. The case lid has a central portion and a sensor hole portion disposed at the central portion through which the sensor is inserted. The cover portion exposes the central portion of the case lid from the hole portion. Light from the light source is emitted to the outside through the central portion.

Advantages of the Invention

[0007] According to the present invention, light from the light source is emitted to the outside through the central portion, and the cover portion exposes the central portion of the case lid from the hole portion at its center. As a result, the light from the light source can be visually recognized regardless of the direction, and there is no need to adjust the orientation of the thermal sensor. Therefore, the installation work can be facilitated.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0009] Embodiment 1. FIG. 1 is a perspective view showing the appearance of the heat sensor according to Embodiment 1. The heat sensor 100 is installed in, for example, a monitoring space in a building and monitors the surrounding temperature. When the surrounding temperature becomes equal to or higher than a certain temperature, the heat sensor 100 outputs a signal indicating a fire to a fire receiver (not shown).

[0010] FIG. 2 is an exploded perspective view showing the configuration of the heat sensor of FIG. 1. As shown in FIG. 2, the heat sensor 100 includes a case body 10 having an opening 11, a substrate 20, a sensor 40 for detecting heat, a light source 50 for emitting light, a case lid 30 disposed at the opening 11 of the case body 10, and a protector 60 for protecting the sensor 40.

[0011] As shown in FIG. 2, the substrate 20 is housed in the case body 10 through the opening 11. Various electronic components including the sensor 40 and the light source 50 are mounted on the substrate 20. The case lid 30 is detachably attached to the case body 10 in which the substrate 20 is housed. A first hole 31 through which the sensor 40 is inserted is formed in the central portion 30c of the case lid 30. The protector 60 is provided to protect the tip of the sensor 40 protruding in the heat sensor 100. A second hole 61 through which an air flow passes is formed in the protector 60. The second hole 61 will be described later. Further, the central portion 30c of the case lid 30 is exposed from a third hole 64a provided at the center of the cover portion 64 of the protector 60 to be described later. The central portion 30c of the case lid 30 forms the central portion 30c of the heat sensor 100. Similarly, the first hole 31 forms the first hole 31 of the heat sensor 100.

[0012] FIG. 3 is a side view showing the state where the thermal sensor of FIG. 1 is installed on the ceiling. As shown in FIG. 3, the thermal sensor 100 is installed, for example, on the ceiling 200 or the like in which the recess 202 is formed on the side opposite to the monitoring space. Specifically, the case body 10 is housed in the recess 202 of the ceiling 200, and the thermal sensor 100 is installed on the ceiling 200 such that the protector 60 protrudes from the ceiling surface 201 into the monitoring space.

[0013] In each figure, the arrow Z direction is described as representing the height direction (vertical direction) of the thermal sensor 100 when installed on the ceiling 200. That is, in the state where the thermal sensor 100 is installed on the ceiling 200 as shown in FIG. 3, the side closer to the floor is defined as the bottom. In the state where the thermal sensor 100 is installed on the ceiling 200, the case body 10 constituting the upper outer surface of the thermal sensor 100 faces the inner surface of the recess 202 of the ceiling 200, and the protector 60 constituting the lower outer surface of the thermal sensor 100 is exposed indoors. Also, in each figure, the arrow X direction represents the width direction (left - right direction) of the thermal sensor 100, and the arrow Y direction represents the depth direction (front - back direction) of the thermal sensor 100. As shown in FIG. 2, the opening 11 of the case body 10 is formed on the lower surface of the case body 10. In the example shown in FIG. 2, the case body 10 has a box shape with an open lower surface. Also, in the case lid 30, the first hole 31 is formed in the central portion 30c.

[0014] (Configuration of Protector 60) FIG. 4 is a bottom view of the thermal sensor of FIG. 1. FIG. 5 is a cross - sectional view showing the A - A cross - section of FIG. 4. FIG. 6 is a cross - sectional view showing the B - B cross - section of FIG. 4. As shown in FIGS. 1, 2, 5 to 6, the protector 60 has a top plate 62 facing the central portion 30c, a cover portion 64 provided above the top plate 62, and a plurality of support columns 63 supporting the top plate 62. The cover portion 64 is attached to the case body 10 and is disposed below the case body 10 so as to cover the recess 202 of the ceiling 200 in the state where the thermal sensor 100 is attached to the ceiling 200. The plurality of support columns 63 connect the top plate 62 and the cover portion 64.

[0015] Further, as shown in FIGS. 1, 2, 5 to 6, a third hole portion 64a is formed in the center of the cover portion 64, and as shown in FIGS. 1, 2, and 4, the cover portion 64 has a disk shape. A sensor 40 protruding from the case body 10 is inserted through the first hole portion 31 of the central portion 30c into the third hole portion 64a.

[0016] Also, although not shown, two springs extending from the surface on the case body 10 side to the outer peripheral side are provided on the cover portion 64 of the protector 60. In a state where the case body 10 is accommodated in the recess 202 of the ceiling 200 as shown in FIG. 3, the two springs provided on the protector 60 push the left and right inner surfaces of the recess 202, so that the case body 10 does not fall out of the recess 202 of the ceiling 200. The attachment configuration of the heat sensor 100 to the ceiling 200 is not limited to such a configuration. Further, as shown in FIG. 3, the outer diameter Do2 of the cover portion 64 is made larger than the width of the case body 10, so that the case body 10 and the recess 202 are not visible to the user.

[0017] As shown in FIGS. 1, 2, 4 to 6, a top plate opening 61a is formed in the center of the top plate 62, and as shown in FIGS. 1, 2, and 4, the top plate 62 has a disk shape. As shown in FIGS. 3 and 4, in the protector 60, the outer diameter Do1 of the top plate 62 is made smaller than the outer diameter Do2 of the cover portion 64. Incidentally, the outer diameter Do1 of the top plate 62 and the outer diameter Do2 of the cover portion 64 may be the same diameter, or the outer diameter Do1 of the top plate 62 may be made larger than the outer diameter Do2 of the cover portion 64. Further, the outer diameter, inner diameter, or the difference between the outer diameter and the inner diameter of the top plate 62 is determined so that the central portion 30c can be seen through the second hole portion 61 (see FIG. 2) of the protector 60 when the user views the heat sensor 100 at a predetermined elevation angle. Here, the predetermined elevation angle is the angle at which the user looks up at the heat sensor 100. For example, it may be the angle at which a user located 15 meters laterally from the heat sensor 100 looks up at the heat sensor 100 installed at a height of 3 meters from the floor. As shown in FIG. 5, the inner diameter Di1 of the top plate 62, that is, the opening width of the top plate opening 61a, is preferably set to a dimension (for example, 8 mm or less) that can prevent a test finger or the like from entering.

[0018] As shown in FIG. 4 in the bottom view of the thermal sensor 100, the center of the top plate opening 61a of the top plate 62 coincides with the center of the third hole 64a (see FIG. 1) of the cover portion 64. Further, as shown in FIG. 5, the center of the top plate opening 61a and the center of the third hole 64a in the protector 60 and the center of the first hole 31 are located on a straight line extending in the vertical direction (arrow Z direction), and the sensor 40 is arranged along this straight line.

[0019] As shown in FIG. 5, the inner diameter Di1 of the top plate 62, that is, the opening width of the top plate opening 61a, is set to a dimension equal to or less than the inner diameter Di2 of the cover portion 64, that is, the opening width of the third hole 64a. Further, the opening widths of the top plate opening 61a and the third hole 64a are larger than the diameter Ds of the tip of the sensor 40 to be inserted, and preferably, are larger than the opening width Di0 of the first hole 31 of the case lid 30. With such a configuration, as shown in FIG. 4 in the bottom view of the thermal sensor 100, the central portion 30c of the case lid 30 located inside the protector 60 is visible from the outside of the thermal sensor 100 through the top plate opening 61a of the protector 60.

[0020] As shown in FIGS. 1 and 2, the support columns 63 of the protector 60 are formed of, for example, plate-shaped members, and a plurality of support columns 63 are arranged radially with a gap G between adjacent support columns 63. The gap G is preferably sized (e.g., 8 mm or less) to prevent the insertion of a test finger or the like. A plurality of support columns 63 and the top plate 62 provided below the central portion 30c constitute a protection portion that protects the tip of the sensor 40 from fingers or the like. In Embodiment 1, the support columns 63 are formed of light-blocking members. As shown in FIGS. 1 and 5, each support column 63 extends downward from the periphery of the third hole portion 64a on the lower surface of the cover portion 64 and is connected to the periphery of the top plate opening 61a on the upper surface of the top plate 62. And, as shown in FIG. 3, the outer diameter Do1 of the top plate 62 is set to be larger than the outer diameter Do3 formed by a plurality of support columns 63 arranged radially. With such a configuration, as shown in FIGS. 1 and 3, the plurality of support columns 63 of the thermal sensor 100 can be made less visible to the user, improving the design quality.

[0021] As shown in FIGS. 5 and 6, an air flow passage space SP is formed in the protector 60 by the top plate 62, the plurality of support columns 63, the cover portion 64, and the central portion 30c of the protector 60. And, in a state where the thermal sensor 100 is installed on the ceiling 200, vertical air flow flows into the flow passage space SP through the top plate opening 61a. Here, the vertical air flow refers to an air flow that flows in a direction perpendicular to the ceiling surface 201. Also, horizontal air flow flows into the flow passage space SP through the gap G formed between the support columns 63, and the air flow in the flow passage space SP flows out of the thermal sensor 100. Here, the horizontal air flow refers to an air flow that flows in a direction parallel to the ceiling surface 201. That is, the top plate opening 61a provided in the top plate 62 and the gap G between the plurality of support columns 63 each function as a second hole portion 61 (see FIG. 2) through which air flow passes in the protector 60.

[0022] (Configuration of the case lid 30) As shown in Fig. 5, the first hole 31 formed in the central portion 30c provided in the case lid 30 has a size larger than the diameter Ds of the heat sensing portion protruding from the case lid 30 in the sensor 40 so that the sensor 40 can be inserted during the assembly of the heat sensor 100. The case lid 30 has a frame member 34 and is configured to cover the lower end of the substrate 20 while exposing the heat sensing portion 41 of the sensor 40 to the outside from the first hole 31 in the central portion 30c. Here, the central portion 30c of the case lid 30 is specifically a region exposed in the flow space SP in the case lid 30. In the example shown in Fig. 2, the frame member 34 has a rectangular shape, and the central portion 30c is formed in the center of the frame member 34. Note that the frame member 34 and the central portion 30c in the case lid 30 may be configured as separate members. Further, the frame member 34 is not limited to a rectangular shape.

[0023] In addition, the case lid 30 covers the lower end of the substrate 20 while exposing the heat sensing portion 41 to the outside, and the case lid 30 may be configured only by the frame member 34, and the central portion 30c may be configured separately from the case lid 30. In this case, the central portion 30c may be integrally formed with the cover portion 64 of the protector 60.

[0024] The case lid 30 is made of a light-transmitting member. As shown in Fig. 5, the first hole 31 has a mortar shape in which the opening width gradually increases from the upper side of the central portion 30c, that is, the side facing the light source 50, to the lower side, that is, the outside where the protector 60 is provided. Note that in this embodiment, the first hole 31 is described as having a mortar shape, but the shape of the first hole 31 is not limited to this. The opening width Di0 of the first hole 31 on the upper side of the central portion 30c is larger than the thickness Ds of the tip of the sensor 40 inserted into the first hole 31, and is dimensioned to be the same diameter as the inner diameter Di1 of the top plate 62 of the protector 60 or smaller than the inner diameter Di1.

[0025] Also, as shown in FIG. 2, the case lid 30 is formed with an injection port 32 for injecting a filler into the case body 10 during the manufacture of the heat sensor 100. The filler will be described later. The injection port 32 is provided outside the first hole 31 formed in the center of the case lid 30, and in the example shown in FIG. 2, it is provided at the four corners of the case lid 30. Note that the injection port 32 can be omitted. When the injection port 32 is omitted, the filler can be injected through the first hole 31.

[0026] (Substrate 20) As shown in FIG. 2, the substrate 20 is composed of, for example, a rectangular printed circuit board. In the example shown in FIG. 2, the substrate 20 has a substantially rectangular shape with a long side extending in the vertical direction (arrow Z direction), and is arranged in the case body 10 such that both sides of the substrate 20 face forward and backward. Various electronic components are mounted on the substrate 20 to form a control circuit.

[0027] FIG. 7 is a cross-sectional view showing the D-D cross-section of FIG. 5. As shown in FIGS. 5 and 7, a light source 50 and a sensor 40 are attached by soldering at predetermined positions on the front surface 21 of the substrate 20. A first notch 23 is formed at the center in the left-right direction (arrow X direction) at the lower end of the substrate 20. Second notches 24 are formed at positions separated from the center in the left-right direction (arrow X direction) at the lower end of the substrate 20 by a certain distance K to the left and right, respectively.

[0028] The control circuit formed on the substrate 20 receives the output value of the sensor 40 and determines the ambient temperature based on the output value. Then, when it is determined that the ambient temperature is equal to or higher than a certain temperature, the control circuit transmits a fire signal to a receiver (not shown) and controls the light source 50 to turn on or blink. Note that the control circuit may be configured to transmit a fire signal to the receiver when there is a temperature change equal to or higher than a set value in a short period of time, or may be configured to transmit temperature information to the receiver and perform a fire determination at the receiver.

[0029] (Sensor 40) As shown in FIGS. 5 and 6, the sensor 40 has a heat-sensitive part 41 that detects heat, and detects the heat of the air flow that has flowed into the flow space SP. The heat-sensitive part 41 is composed of, for example, a thermistor whose resistance changes due to heat transmitted from the air flow, and converts a temperature change into an electrical signal and outputs it.

[0030] The sensor 40 is composed of, for example, a heat-sensitive part 41, a rod-shaped lead part 42 made of lead wires, a sensor base 44 having two pins to be attached to the substrate 20, and a connection part 43 that connects the lead part 42 and the sensor base 44. The heat-sensitive part 41 is attached to the tip of the lead part 42, and the heat-sensitive part 41 and the lead part 42 are integrally coated. The connection part 43 connects the base end of the lead part 42 and the tips of the two pins of the sensor base 44, and is covered with resin or the like. Then, the two pins of the sensor base 44 are fixed to the front surface 21 of the substrate 20 by soldering, and the heat-sensitive part 41 is electrically connected to the control circuit of the substrate 20.

[0031] In order to detect the heat of the vertical air flow, the heat-sensitive part 41 is arranged directly above the center of the top plate opening 61a of the protector 60 in the flow space SP. Specifically, the heat-sensitive part 41 is arranged at a preset position in the flow space SP by the sensor base 44 and the lead part 42 connected to the sensor base 44. In the example shown in FIGS. 5 and 6, the sensor 40 is arranged in a direction parallel to the substrate 20 arranged in the vertical direction (arrow Z direction) in the case body 10.

[0032] As described above, since the sensor 40 is composed of a plurality of components, the thickness of the sensor 40 is not constant in the vertical direction. For example, the connection part 43 is the thickest. Therefore, in the present embodiment, as shown in FIGS. 5 and 6, the connection part 43 is arranged in the first notch 23 of the substrate 20. With such a configuration, even when a sensor 40 with a non-constant thickness is used, it is possible to arrange the sensor 40 so that the lead part 42 extends in the vertical direction (arrow Z direction) while avoiding the sensor 40 from contacting the substrate 20 at a portion other than the sensor base 44.

[0033] Note that the sensor 40 may be configured such that the sensor base 44 is fixed to the lower end on the front surface 21 of the substrate 20 so that the heat-sensitive portion 41 is located on the extension line below the substrate 20. In this case, the connection portion 43 of the sensor 40 may be disposed between the lower end of the substrate 20 and the inner surface of the case lid 30, and the first notch portion 23 can be omitted.

[0034] (Light source 50) FIG. 8 is a cross-sectional view showing the C-C cross-section of FIG. 4. The light source 50 is composed of, for example, an LED (Light Emitting Diode) or the like. As shown in FIGS. 5, 7, and 8, the light source 50 is soldered to the front surface 21 of the substrate 20 at the upper part of the light source 50 so that the light emitting surface 51 (see FIG. 8) faces downward. The light source 50 is preferably mounted on the front surface 21 of the substrate 20 at the lower end portion on the central portion 30c side of the case lid 30. By providing the light source 50 in this way in the vertical direction (arrow Z direction), it is possible to suppress the light emitted from the light source 50 from being blocked by the substrate 20.

[0035] In the example shown in FIGS. 2, 5, and 7, two light sources 50 are mounted on the substrate 20, one light source 50 is disposed on the right side of the sensor 40, and the other light source 50 is disposed on the left side of the sensor 40. Specifically, as shown in FIG. 5, when the substrate 20 is viewed from the front, the upper part of the light source 50 is fixed to the front surface 21 of the substrate 20 at the peripheral portion of the second notch portion 24 of the substrate 20 so that at least a part of the light emitting surface 51 does not overlap with the substrate 20 disposed behind the light source 50. With such a configuration, it is possible to suppress the progress of the light radiated from the light emitting surface 51 of the light source 50 and traveling rearward and downward from being blocked by the substrate 20, and more light can be made to enter the central portion 30c compared with the case where the second notch portion 24 is not provided.

[0036] In the present embodiment, although the central portion 30c provided on the case lid 30 has been described as being formed of a light-transmitting member, the central portion 30c may be formed of an opaque member, and a light-transmitting hole for emitting light may be provided in the central portion 30c. In this case, the first hole portion 31 may be used as the light-transmitting hole, or a light-transmitting hole may be provided in the central portion 30c separately from the first hole portion 31.

[0037] In the example shown in FIG. 5, the light source 50 is provided such that the center of the light-emitting surface 51 and the center of the second notch portion 24 coincide in the left-right direction (arrow X direction). That is, the distance between the center position of the sensor 40 and the center position of each light source 50 is the same as the distance K between the center of the first notch portion 23 and the center of each second notch portion 24, and is the same for the two light sources 50. The distance (2K) between the two light sources 50 in the left-right direction (arrow X direction) is preferably equal to or less than the inner diameter Di2 of the cover portion 64 of the protector 60, that is, the opening width of the third hole portion 64a. In this case, the light of each light source 50 can be made more visible through the first hole portion 31.

[0038] Furthermore, in the present embodiment, since the central portion 30c is formed of a light-transmitting member, light can be emitted from the central portion 30c through the circulation space SP. Also, in the present embodiment, since the first hole portion 31 has a mortar shape in the central portion 30c formed of a light-transmitting member, the light emitted from the light source 50 can be diffused in the central portion 30c.

[0039] When the central portion 30c is formed of a light-transmitting member, the distance (2K) between the two light sources 50 in the left-right direction (arrow X direction) may be made longer than the opening width Di0 of the first hole portion 31, and the light of the two light sources 50 may be arranged to enter the case lid 30. Thereby, the light emitted from the light source 50, particularly the downward-directed light with strong intensity, can be made to enter and be diffused by the light-transmitting member of the case lid 30, so that the directivity of the light can be suppressed.

[0040] Further, the distance (2K) between the two light sources 50 in the left - right direction (arrow X direction) may be further increased to be larger than the opening width of the top - plate opening 61a (inner diameter Di1 of the top - plate 62). Thereby, the locally bright portion directly below the light source 50 in the central portion 30c can be covered by the top - plate 62.

[0041] Also, in order to make the light emitted by the light source 50 provided at the lower end of the substrate 20 enter the widest possible range in the central portion 30c, as shown in FIG. 5, it is preferable that the lower end of the substrate 20 and the central portion 30c have a certain distance.

[0042] (Case body 10) As shown in FIG. 7, the case body 10 (see FIG. 5) has a case outer - shell 12 having a box - shape with an open bottom surface, and a substrate - holding portion 13 formed on the inner surface of the case outer - shell 12 for holding the substrate 20. When the heat sensor 100 is installed on the ceiling 200, the outer surface of the case outer - shell 12 and the inner surface of the recess 202 of the ceiling 200 face each other (see FIG. 3).

[0043] As shown in FIG. 7, the substrate - holding portion 13 is provided on the inner surfaces of the left - hand side wall and the right - hand side wall of the case outer - shell 12 respectively. The substrate - holding portion 13 provided on the right - hand side wall of the case outer - shell 12 is composed of two protruding portions 13a arranged in the front - rear direction (arrow Y direction) protruding from the inner surface of the right - hand side wall, and a groove portion 13b formed between the two protruding portions 13a. The substrate - holding portion 13 provided on the left - hand side wall of the case outer - shell 12 is composed of two protruding portions 13a arranged in the front - rear direction (arrow Y direction) protruding from the inner surface of the left - hand side wall, and a groove portion 13b formed between the two protruding portions 13a. The width of each groove portion 13b is slightly wider than the thickness of the substrate 20, and by fitting the right - hand end portion and the left - hand end portion of the substrate 20 into the groove portions 13b of the two substrate - holding portions 13 respectively, the substrate 20 is arranged at the set position in the case body 10.

[0044] Also, as shown in FIG. 2, in each substrate holding portion 13, the two protruding portions 13a extend in the vertical direction (arrow Z direction) of the thermal sensor 100, and when the substrate 20 is inserted into the case body 10 through the opening 11, it also functions as a guide for the substrate 20.

[0045] As shown in FIG. 7, the central position (represented by point C1) of each groove portion 13b in the front-rear direction (arrow Y direction) is slightly shifted backward from the central position (represented by the virtual line L1) of the case outline 12 in the front-rear direction (arrow Y direction). By providing the substrate holding portion 13 in this way, the substrate 20 can be arranged slightly rearward of the central position of the case outline 12 represented by the virtual line L1 within the case body 10. Therefore, as shown in FIG. 7, even when the sensor 40 is fixed to the front surface 21 of the substrate 20, the sensor 40 can be arranged at the central position of the thermal sensor 100 in the front-rear direction (arrow Y direction). Also, for the light source 50 fixed to the front surface 21 of the substrate 20 in the same way as the sensor 40, it can be arranged at approximately the central position in the front-rear direction (arrow Y direction) of the thermal sensor 100 and can be visually recognized from the central portion 30c.

[0046] Although not shown, the space inside the case body 10 is filled with a filler through the injection port 32 of the case lid 30 during the manufacture of the thermal sensor 100. When the filler hardens, the substrate 20 on which various electronic components are mounted, the case body 10, and the case lid 30 are fixed. Also, when the filler hardens, the substrate 20 is waterproofed. As the filler, a transparent or translucent member that transmits light, such as polyurethane, is used. The filler is preferably provided so that the light source 50 mounted on the substrate 20 is covered by the filler. Thereby, the light emitted by the light source 50 can be diffused in the filler, and the concentration of light incident locally on the central portion 30c can be suppressed.

[0047] Based on FIGS. 3 and 6, the flow of air currents during a fire will be described. When a fire breaks out in the monitored space, a vertical air current is generated from the fire source towards the ceiling 200. After the vertical air current reaches the ceiling 200, the direction of the air current becomes parallel to the ceiling 200 and flows along the ceiling 200 as a horizontal air current. If the fire source is directly below the heat detector 100, the vertical air current reaches the top plate 62 or the cover portion 64 of the protector 60. Also, when the fire source is not directly below the heat detector 100, all the vertical air currents rising from the fire source reach the ceiling 200, flow along the ceiling surface 201 as a horizontal air current, reach the heat detector 100, and flow in through the gap G of the support column 63. The hot air current flowing into the circulation space SP from the gap G of the support column 63 flows out through the gap G between another support column 63 through the circulation space SP.

[0048] Among the hot air currents reaching the protector 60 from the fire source, the hot air current reaching the central part of the top plate 62 flows into the circulation space SP from the top plate opening 61a, passes through the circulation space SP, and flows out of the heat detector 100 through the gap G between another support column 63. Also, among the hot air currents reaching the protector 60, the hot air current reaching the peripheral part of the top plate opening 61a on the top plate 62 flows along the top plate 62, and a part of it flows into the circulation space SP through the top plate opening 61a. The hot air current flowing into the circulation space SP through the top plate opening 61a flows out of the heat detector 100 through the gap G between the support columns 63 through the circulation space SP. The remaining hot air current flowing along the top plate 62 rises from the outer peripheral surface of the top plate 62 to the cover portion 64, merges with the hot air current flowing out of the circulation space SP through the gap G between the support columns 63, and flows along the ceiling 200.

[0049] Among the hot air currents reaching the protector 60 from the fire source, the hot air current reaching the cover portion 64 advances along the cover portion 64. When it reaches near the support column 63, it flows into the protector 60 through the gap G between the support columns 63, passes through the circulation space SP, and flows out through the gap G between another support column 63.

[0050] Heat is transmitted from the hot air flow passing through the central part of the flow space SP to the heat-sensitive part 41. When heat is transmitted to the heat-sensitive part 41, the control circuit detects a temperature change based on the signal sent to the substrate 20 via the lead part 42, a fire signal is transmitted from the control circuit to a receiver (not shown), and the light source 50 is driven by the control circuit to emit light.

[0051] FIG. 9 is an explanatory diagram showing a state in which the light source emits light in the heat detector of FIG. 5. In FIG. 9, the dashed arrow represents an example of a group of light rays emitted into the flow space SP through the central part 30c among the light emitted by the light source 50. Also in FIG. 9, the dash-dotted arrow represents an example of a group of light rays emitted outside the heat detector 100 through the second hole part 61 (see FIG. 2) of the protection part in the protector 60 among the light emitted into the flow space SP through the central part 30c.

[0052] The light emitted by the light source 50 is emitted into the flow space SP in the protector 60 through the circular first hole part 31 formed in the central part 30c, and illuminates the part of the protector 60 facing the flow space SP. Then, the light emitted into the flow space SP is emitted outside the heat detector 100 through the circular top plate opening 61a formed at the center of the top plate 62 of the protector 60 and the gap G between a plurality of struts 63 radially arranged on the side surface of the protector 60. Therefore, since light is emitted from the central part of the heat detector 100, the user can visually recognize the light emission indicating the operation of the heat detector 100 no matter from which direction the user views around the sensor 40. As described above, when the central part 30c is composed of a light-transmitting member, the heat detector 100 can emit light through the central part 30c without emitting light through the first hole part 31. Also, when the central part 30c is composed of an opaque member, the user can visually recognize the light emission of the light source 50 through the light-transmitting hole provided in the central part 30c.

[0053] In addition, since the central portion 30c is composed of a light-transmitting member and the first hole portion 31 is in the shape of a mortar, the surface area from which light is emitted in the central portion 30c is increased, and the configuration is such that it is easy to visually recognize the thermal sensor 100 even when viewed from the side (front, rear, left or right). Further, in the present embodiment, since the central portion 30c is provided on the case lid 30 and the entire case lid 30 is composed of a light-transmitting member, there is no need to provide a light guide separately from the case lid 30 as in the prior art. Also, compared with the case of guiding light by an L-shaped light guide as in the prior art, light loss can be reduced and light can be used with high efficiency.

[0054] In FIG. 9, the two white arrows E1 and E2 respectively represent the lines of sight of users with different elevation angles. Hereinafter, for each case, the components that can be visually recognized by the user will be described. Hereinafter, the elevation angle indicated by the white arrow E1 is referred to as the first elevation angle, and the elevation angle indicated by the white arrow E2 is referred to as the second elevation angle. The second elevation angle is smaller than the first elevation angle.

[0055] When the user views the thermal sensor 100 at the first elevation angle indicated by the white arrow E1, the central portion 30c can be visually recognized through the top plate opening 61a of the protector 60, and the light of the light source 50 emitted can be confirmed. Also, when the user views the thermal sensor 100 at the second elevation angle indicated by the white arrow E2, the central portion 30c can be visually recognized through the gap G between the plurality of columns 63 of the protector 60. In this case, as shown in FIG. 9, when the user looks up at the thermal sensor 100 from the left side, the inner surface on the right side of the first hole portion 31 having a mortar shape in the central portion 30c can be seen from substantially the front, and the light can be confirmed.

[0056] As described above, in the first embodiment, the thermal sensor 100 includes a case body 10 that houses a substrate 20 on which a sensor 40 for sensing heat and a light source 50 are mounted, and has an opening 11 on the lower surface, and a cover portion 64. The cover portion 64 is disposed below the case body 10, and a first hole 31 through which the sensor 40 is inserted is arranged at the central portion 30c. In the thermal sensor 100, light from the light source 50 is emitted to the outside through the central portion 30c. As a result, light can be visually recognized from any direction around the sensor 40, so there is no need to adjust the orientation of the thermal sensor 100 during the installation work, and the installation work can be facilitated.

[0057] Note that the embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made. For example, the shape of the case outer shell 12 is not limited to the above case, and for example, it can be a cylindrical shape having an upper surface. Also, for example, although the case lid 30 is entirely made of a light-transmitting member, only the central portion 30c of the case lid 30 may be made of a light-transmitting member, and the portions other than the central portion 30c of the case lid 30 may be made of a light-blocking member. Further, regarding the second hole 61, it is configured by the top plate opening 61a and the gap G, but it is not limited to this, and it may be configured only by the top plate opening 61a or only by the gap G. Also, the above-described thermal sensor 100 can be installed on the side wall of a room. In this case, the thermal sensor 100 is installed on the side wall so that the light-emitting side of the central portion 30c, that is, the protector 60 side, is exposed to the interior of the room. Even in this case, there is no need to adjust the orientation of the thermal sensor 100 during installation, and the labor during installation can be saved.

[0058] Second Embodiment. FIG. 10 is a perspective view showing the appearance of the thermal sensor according to the second embodiment. The thermal sensor 100 of the second embodiment is different from the case of the first embodiment in that two lid protrusions 33 are provided on the case lid 30, and a part of a plurality of support columns 63 is constituted by the lid protrusions 33. Also, the thermal sensor 100 of the second embodiment is different from the case of the first embodiment in that strip-shaped springs 70 extending outward are provided on the left and right side walls of the case body 10. Note that the shape of the spring is not particularly limited to this.

[0059] In a state where the case body 10 is housed in the recess 202 of the ceiling 200 (see FIG. 3), since the two springs 70 provided on the case body 10 press the left and right inner surfaces of the recess 202 in the ceiling 200, it is possible to prevent the case body 10 from falling out of the recess 202 of the ceiling 200.

[0060] The two lid protrusions 33 are provided so as to protrude toward the protector 60 on the right side and the left side of the mortar-shaped first hole 31. More specifically, the two lid protrusions 33 are provided along the center line in the front-rear direction (arrow Y direction) of the case lid 30 so as to be located directly below the two light sources 50 fixed to the substrate 20. The case lid 30 including the two lid protrusions 33 is composed of a light-transmitting member.

[0061] In addition, two first through holes 64b are provided on the right side and the left side of the third hole 64a in the cover portion 64 of the protector 60. Further, two second through holes 62b are provided at positions on the top plate 62 of the protector 60 that face the two first through holes 64b of the cover portion 64. The two lid protrusions 33 extending downward from the case lid 30 are respectively inserted into the first through holes 64b of the cover portion 64 of the protector 60 and exposed from the protector 60 through the second through holes 62b of the top plate 62. That is, in the thermal sensor 100 of the second embodiment, the support column of the protector 60 is composed of an opaque support column 63 and two lid protrusions 33 made of a light-transmitting member.

[0062] Thereby, the light of the light source 50 can be guided directly downward through the I-shaped lid protrusion 33 provided on the case lid 30 and emitted from the protector 60. Therefore, compared with the case of using an L-shaped light guide as in the prior art, the light of the light source 50 can be used with high efficiency.

[0063] When removing the thermal sensor 100 from the installation wall, the operator may hold the top plate 62 and the support columns 63 of the protector 60. Therefore, it is preferable to set the number of support columns to a certain number or more to ensure the strength of the protector 60. On the other hand, in order to improve the visibility of the thermal sensor 100 when the light source 50 is emitting light, it is preferable to set the size of the gap G between the support columns to a certain size or more. In the thermal sensor 100 of Embodiment 2, since a part of the support columns is constituted by two lid protrusions 33 made of a light-transmitting member, it is possible to ensure the strength by setting the number of support columns to a certain number or more, and to improve the visibility by making it easier to see inside the protector 60.

Explanation of Reference Numerals

[0064] 10 Case body, 11 Opening, 12 Case outer shell, 13 Substrate holding part, 13a Protrusion, 13b Groove part, 20 Substrate, 21 Front surface, 23 First notch part, 24 Second notch part, 30 Case lid, 30c Central part, 31 First hole part, 32 Injection port, 33 Lid protrusion, 34 Frame member, 40 Sensor, 41 Heat-sensitive part, 42 Lead part, 43 Connection part, 44 Sensor base, 50 Light source, 51 Light-emitting surface, 60 Protector, 61 Second hole part, 61a Top plate opening, 62 Top plate, 62b Second through hole, 63 Support column, 64 Cover part, 64a Third hole part, 64b First through hole, 70 Spring, 100 Thermal sensor, 200 Ceiling, 201 Ceiling surface, 202 Concave part, Di0 Opening width, Di1 Inner diameter, Di2 Inner diameter, Do1 Outer diameter, Do2 Outer diameter, Do3 Outer diameter, Ds Diameter, G Gap, K Distance, L1 Virtual line, SP Flow space.

Claims

1. a case body that houses a substrate on which a heat sensor and a light source are mounted and has an opening on a lower surface; a case lid disposed at the opening of the case body; a cover portion disposed below the case body and the case lid so as to cover the opening and having a hole at the center, the case lid has a central portion and a sensor hole portion disposed in the central portion and through which the sensor is inserted, the cover portion is disposed so as to expose the central portion of the case lid through the hole, The light from the light source is emitted to the outside through the central portion. heat detector.

2. The cover portion is disposed so that the lower end of the central portion is at the same height as the lower surface of the cover portion. The heat detector according to claim 1.

3. the sensor hole has a mortar shape with an opening width gradually increasing toward the bottom, and a bottom end of the sensor hole is disposed at the same height as a bottom surface of the cover portion; A heat detector according to claim 1 or 2.

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