Flame detector operation test device

Abstract

This invention provides a flame detector operation test device that can emit test light that takes into account the flickering of the flame. [Solution] In a flame detector operation test device that incorporates a lamp, a drive circuit (43) that supplies current to the lamp to light it, and a control means (42), and is capable of emitting light of a predetermined wavelength in a certain direction, the control means is configured to increase or decrease the current supplied from the drive circuit to the lamp at a predetermined period to cause the lamp to blink periodically, and is configured so that the lighting time during blinking is set to be longer than the off time. Furthermore, a lens (23) is provided in front of the lamp, and the lens is provided with a filter layer (23A) that transmits light in a predetermined wavelength range corresponding to the wavelength detected by the flame detector under test and blocks or attenuates light outside the predetermined wavelength range.

Description

Technical Field

[0001] The present invention relates to a technique that is useful for being used in an operation test device for a flame detector that emits light of a predetermined wavelength in order to perform an operation test of the flame detector.

Background Art

[0002] Among the fire detectors used in a fire alarm system, there are various types such as a heat detector using a thermistor, a photoelectric smoke detector, and a flame detector that includes an element such as an infrared sensor and captures light of a wavelength specific to a flame for detection, and they are used appropriately according to the installation location. For example, in a hydrogen station equipped with equipment for supplying hydrogen, which is the fuel of a fuel cell vehicle, in order to detect a fire caused by hydrogen leakage that occurs when filling a hydrogen vehicle with hydrogen, as shown in FIG. 1, a flame detector 50 that detects light of a specific wavelength emitted by a hydrogen flame is installed at a high place of a building 40 such as a canopy (roof).

[0003] Conventionally, in order to confirm the operation of a flame detector, a flame detector operation tester (hereinafter referred to as an operation tester) has been used. The operation tester is implemented by irradiating a flame detector with a pseudo-flame (test light) of a specific wavelength from a lamp built inside the main body. As an invention related to a flame detector operation tester having such a function, there is one described in Patent Document 1. Further, since a flame detector is generally installed at a high place inside equipment, and there is a desire for an operator to perform the operation of the operation tester while standing on the ground, there is an operation tester having a configuration that allows an operator to operate on the ground and irradiate test light obliquely upward (Patent Documents 2 and 3).

[0004] In the operation tester described in Patent Document 3, in order to irradiate a flame detector with light of a specific wavelength emitted by a flame to be detected, a filter is arranged in front of the lamp. Further, in the operation tester described in Patent Document 1, a light shielding plate having a plurality of apertures is arranged in front of the lamp, and is configured to reproduce and irradiate test light having the same spectral ratio as a flame according to the area ratio of the plurality of apertures.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-264847 [Patent Document 2] Japanese Patent Publication No. 2003-173481 [Patent Document 3] Japanese Patent Application Publication No. 11-110657 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The target of a flame detector is a flame, and flames in an actual fire fluctuate. While the inventions of operational testers described in Patent Documents 2 and 3 mention emitting test light while taking fluctuations into consideration, it has become clear that when conducting operational tests of a flame detector that detects the occurrence of a fire by detecting not only infrared light but also light in other wavelength ranges such as ultraviolet light, such as in a hydrogen flame, simply flashing a lamp that serves as the test light source is insufficient when conducting the test from the ground, as it is not possible to output sufficient test light in multiple wavelength ranges.

[0007] This invention was made in view of the above-mentioned problems, and its objective is to provide an operational test device for a flame detector that can emit test light containing multiple wavelengths that take into account the fluctuations of the flame. [Means for solving the problem]

[0008] To solve the above problems, this invention provides: In a flame detector operation test device that incorporates a lamp, a drive circuit for illuminating the lamp by supplying current, and a control means, and is capable of emitting light of a predetermined wavelength in a certain direction, The control means is configured to increase or decrease the current supplied from the drive circuit to the lamp at a predetermined interval to cause the lamp to blink periodically, and the lighting time during blinking is set to be longer than the off time. According to the flame detector operation test device having the above configuration, by periodically flashing the emitted test light, it is possible to emit fluctuating test light that takes into account the fluctuation of the flame, thereby confirming whether the flame detector under test is capable of detecting flames that are fluctuating.

[0009] Furthermore, preferably, the ratio of the on-time to the off-time should be set to 2:1. With this configuration, it is possible to ensure sufficient output of the test light while irradiating the flame detector with test light that takes into account the flicker of the flame, thereby performing an operational test.

[0010] Furthermore, preferably, the control means is configured to blink the lamp at a frequency of 0.3 seconds.

[0011] Furthermore, preferably, the lamp is provided with a lens positioned in front of it. The lens is provided with a filter layer in at least part of it that transmits light in a predetermined wavelength range corresponding to the wavelength detected by the flame detector under test, and blocks or attenuates light outside the predetermined wavelength range. The filter layer is configured to transmit at least a portion of the infrared wavelength range or the ultraviolet wavelength range. With this configuration, it is possible to ensure a sufficient amount of ultraviolet light, for example, among the multiple wavelength bands of test light contained in the emitted light, thereby enabling the flame detector to operate more reliably. [Effects of the Invention]

[0012] The flame detector operation test apparatus of the present invention has the effect of ensuring sufficient light in the specified wavelength range when irradiating a flame detector, which detects the occurrence of a fire by detecting light in two or more wavelength ranges emitted by a flame, with test light containing multiple wavelengths from the ground, and conducting an operation test. [Brief explanation of the drawing]

[0013] [Figure 1]It is an external view showing an example of a hydrogen station where a flame detector is installed. [Figure 2] It is a perspective view showing one embodiment of an operation test apparatus for a flame detector according to the present invention. [Figure 3] It is an exploded perspective view showing the state where the lens unit of the operation test apparatus for a flame detector shown in FIG. 2 is disassembled. [Figure 4] (A) is a cross-sectional view showing the internal structure of the light emitting unit and the lens unit of the operation test apparatus for a flame detector in FIG. 2, and (B) is an enlarged cross-sectional view showing a part of the lens peripheral portion of (A) enlarged. [Figure 5] It is a graph showing the spectra (spectral distributions) of a hydrogen flame and a halogen lamp (halogen lamp). [Figure 6] It is a front view showing an example of the shape and pattern of a filter layer provided on the surface of the glass lens of the operation test apparatus for a flame detector according to the embodiment. [Figure 7] It is a view showing examples of other shapes and patterns of the filter layer provided on the surface of the glass lens. [Figure 8] It is a block diagram showing a configuration example of a lighting drive system for a halogen lamp.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments in the case where the operation test apparatus for a flame detector according to the present invention is applied to an operation test apparatus for a flame detector that detects a hydrogen flame will be described with reference to the drawings. FIG. 3 shows an exploded perspective view showing one embodiment of the operation test apparatus for a flame detector, and FIG. 4 shows a cross-sectional view showing the state where the lens unit of the operation test apparatus for a flame detector in FIG. 3 is disassembled. The operation test apparatus for a flame detector of the present embodiment has a function of holding the handle provided on the test apparatus main body by a human hand and irradiating a pseudo-flame (test light) having a wavelength peculiar to a hydrogen flame from a lamp built into the main body to the flame detector.

[0015] As shown in Figures 2 and 3, the flame detector operation test device (hereinafter referred to as the test device) 10 of this embodiment comprises a cylindrical frame made of aluminum or resin, a lens portion 12 attached to the front end of the test device body 11, and a back cover 13 attached to cover the opening at the rear end of the test device body 11. A handle 14 is provided on the outer surface of the tester body 11, and a switch button 15 for turning on a lamp is provided on the upper surface of the handle 14. In addition, legs 16A and 16B are provided on the outer surface of the tester body 11 opposite the handle 14 to maintain a stable posture when the tester 10 is placed on it.

[0016] Meanwhile, the inside of the test apparatus body 11 houses the halogen lamp 31 that constitutes the light-emitting section, the bulb socket which serves as the lamp's receptacle, the bulb support bracket, as well as a battery, a charging connector, and the lamp's drive circuit. Of these, the light-emitting section is located at the front of the test apparatus body 11, and as shown in Figure 3, a lens section 12 that covers the front of the halogen lamp 31 is provided on the front side of the test apparatus body 11. Here, the halogen lamp 31 used emits light that is close to the spectrum of sunlight as test light, and this test light includes light in the ultraviolet and infrared wavelength bands characteristic of hydrogen flames. The specific configuration of the light-emitting section will be described later.

[0017] As shown in Figure 3, the lens section 12 includes a lens retaining nut 21 that can be fitted to the front opening edge of the tester body 11, a reflector 22 having an opening in the center through which a halogen lamp 31 is inserted and which reflects the light emitted by the halogen lamp 31 forward, a glass lens 23 for transmitting light, and a cylindrical lens cover 24 that is attached to the front of the tester body 11 with the reflector 22 and glass lens 23 housed inside. Although not particularly limited, a bowl-shaped parabolic mirror is used for the reflector 22, and the glass lens 23 is made of quartz glass. The glass lens 23 is equipped with an optical filter function that transmits ultraviolet and infrared rays of wavelengths specific to hydrogen flames and blocks light in unwanted wavelength ranges. The glass lens 23 may have curvature and be an optical lens, or it may be flat without curvature. Preferably, the curvature of the glass lens 23 is designed in combination with the shape of the reflector 22. Specific examples of the glass lens 23 with an optical filter function will be described in detail later.

[0018] A male threaded portion 11a is formed on the outer circumferential surface of the front end of the test device body 11, and a female threaded portion 24a is formed on the inner circumferential surface of the front end of the lens cover 24, as shown in Figure 4(A). By screwing the female threaded portion 24a onto the male threaded portion 11a, the lens cover 24 is attached to the front side of the test device body 11 so as to cover the light-emitting part having the halogen lamp 31. In this configuration, the reflector 22 and the glass lens 23 are fixed in place by having their edges sandwiched between the lens retaining nut 21 and the front edge of the lens cover 24. Furthermore, in this embodiment, a thin, annular heat insulating spacer 25 made of a resin with low thermal conductivity is interposed between the reflector 22 and the glass lens 23, and a waterproof and heat insulating O-ring 26 made of heat-resistant rubber is interposed between the glass lens 23 and the lens cover 24.

[0019] The reflector 22 becomes hot due to the heat from the halogen lamp 31, but the presence of insulating spacers 25 and O-rings 26 in front of and behind the glass lens 23 makes it difficult for heat to transfer between the reflector 22, glass lens 23, and lens cover 24. This prevents temperature unevenness from occurring in the lens and reduces the performance of the lens. In addition, quartz glass can crack due to rapid changes in temperature or localized thermal strain (differences in temperature distribution), but the insulating rings 25 and O-rings 26 prevent the quartz glass lens 23 from cracking due to thermal stress.

[0020] Furthermore, multiple heat dissipation fins 11b and 24b are provided on the outer circumference of the front of the tester body 11 and the outer circumference of the lens cover 24, and are configured to suppress the temperature rise of the light-emitting section having the halogen lamp 31. Furthermore, as shown in Figure 4(B), a gap a may be created on the front side of the edge of the glass lens 23, and a gap b may be created around the glass lens 23. By providing such gaps, heat can be less easily transferred between the reflector 22, the glass lens 23, and the lens cover 24.

[0021] Furthermore, the gap a is created by providing a right-angle step portion 24c on the inner surface of the lens cover 24 to restrict the forward position when screwing in the lens retaining nut 21. In other words, when screwing the lens retaining nut 21 all the way into the lens cover 24 to clamp the edge of the reflector 22, the vertical wall of the right-angle step portion 24c acts as a stopper, preventing further movement. The gap b can be created by setting the outer diameter of the glass lens 23 to be smaller than the inner diameter of the corresponding part of the lens cover 24.

[0022] Next, a specific example of the glass lens 23 in the test apparatus 10 of this embodiment will be described using Figures 5 to 7. Figure 5 shows the spectra (spectral distribution) of a hydrogen flame (Hy) and a halogen lamp (halogen lamp). In Figure 5, A is the wavelength region of visible light. As can be seen from Figure 5, the hydrogen flame has several characteristic spectral peaks in the infrared region. Therefore, in the test apparatus of this embodiment, as mentioned above, a glass lens 23 is used that has an optical filter function that transmits light similar to the spectrum characteristic of the hydrogen flame and blocks light in unwanted wavelength bands.

[0023] The glass lens 23 is made of anhydrous or low-water synthetic quartz glass, and this quartz glass transmits light across the entire wavelength range. On the other hand, the flame detector being tested in this embodiment is equipped with sensors sensitive to light in three wavelength bands: ΔλUV, ΔλIRm, and ΔλIRs, as shown in Figure 5, and detects the occurrence of a hydrogen flame based on the signal amount obtained from these sensors. That is, a hydrogen flame is determined when a certain amount of ultraviolet wavelength (ΔλUV) light is detected and the amount of light at the dominant wavelength (ΔλIRm) is sufficiently greater than the amount of light at the reference wavelength (ΔλIRs). However, the light emitted by the halogen lamp 31 has a greater amount of light at the reference wavelength (ΔλIRs) than at the dominant wavelength (ΔλIRm). Therefore, in the operation test of the detector, it is necessary to dim the light at the reference wavelength (ΔλIRs).

[0024] Therefore, in the glass lens 23 of the test apparatus 10 of this embodiment, as shown in Figure 6, light of the main wavelength (ΔλIRm) is transmitted, and the reference wavelength (Δλ IRs A filter layer (high-pass filter: HPF) 23A that blocks (attenuates) light with wavelengths shorter than T is provided on the surface of the lens in a circular shape. The filter layer 23A is formed by depositing a layer (coating) of a material having selective light transmission characteristics (transmission wavelength range), such as chromium oxide, onto the surface of the lens by vapor deposition. Figure 5 shows that the transmission wavelength band of this filter layer 23A is T F It is shown as follows.

[0025] By the way, when the filter layer 23A is formed over the entire surface of the lens, the ultraviolet wavelength (Δλ) characteristic of hydrogen flames is UVLight of wavelengths up to ) is blocked, making it impossible to detect with a flame detector. Therefore, in the embodiment shown in Figure 6, the filter layer 23A is partially formed on the central part of the glass lens 23 surface, excluding the edges, and the peripheral part of the lens is an uncoated area of ​​the filter layer 23A. In addition, in order to obtain wavelengths and intensities that match the characteristics of the flame detector, the area ratio of the filter layer 23A to the entire lens surface is set to, for example, 90%. Note that the area ratio is not limited to 90%, and should be set appropriately according to the selective light transmission characteristics (transmission wavelength range) and transmittance of the material of the filter layer 23A, the type of lamp used, the wavelength of light detected by the flame detector under test, etc. This allows test light having a wavelength and intensity that matches the detection characteristics of the flame detector under test to be irradiated from the test device 10 to the flame detector.

[0026] Furthermore, the area ratio is not limited to 90%, but is set appropriately according to the selective light transmission characteristics (transmission wavelength range) and transmittance of the filter layer 23A material, the type of lamp used, the wavelength of light detected by the flame detector under test, etc. Also, the formation pattern of the filter layer 23A is not limited to that shown in Figure 6, but can be any shape or pattern as long as the area ratio is within a predetermined range, for example, as shown in Figure 7. In Figure 7, (a) shows a lens 23 with a circular unapplied filter layer portion 23B in the center of its surface, (b) shows a lens 23 with a ring-shaped filter layer 23A on its surface with unapplied filter layers 23B in the center and around the periphery, and (c) shows a lens 23 with multiple circular filter layers 23A dispersed on its surface. Furthermore, (d) shows a lens 23 with a polygonal filter layer 23A in the center of its surface (a pentagon in the figure), (e) shows a lens 23 with numerous rectangular filter layers 23A dispersed on its surface, and (f) shows a lens 23 with a cross-shaped unapplied filter layer portion 23B on its surface.

[0027] Next, the lighting control method for the halogen lamp 31 in the test apparatus 10 of this embodiment will be described. The test apparatus 10 of this embodiment is characterized by driving the lamp to blink at a predetermined period in order to emit test light that takes into account the flickering of the flame. Figure 8 shows a block diagram of an example configuration of a lighting drive system for the halogen lamp 31 that enables such blinking drive.

[0028] As shown in Figure 8, the lighting drive system of this embodiment includes a DC power supply 41 such as a battery, a microprocessor (CPU) 42 that controls the entire system, an amplifier circuit 43 that boosts the voltage from the DC power supply 41 to generate the drive voltage for the lamp 31, and a switch circuit 44 for supplying / cutting voltage from the DC power supply 41 to the amplifier circuit 42. The lighting drive system also includes a pulse generation circuit 45 that generates a pulse signal to give the lamp 31 a blinking cycle, a voltage monitoring circuit 46 that monitors the drive voltage supplied to the lamp 31, an on / off operation button 47 that instructs the lamp to light up, and an indicator light (pilot lamp) 47 that indicates that the system is operating and that a drive voltage is being applied to the lamp.

[0029] When the on / off operation button 47 is pressed on, the CPU 42 turns on the switch circuit 44 to supply voltage from the DC power supply 41 to the amplifier circuit 43, and activates the amplifier circuit 43 and the pulse generation circuit 45. The amplifier circuit 43 then boosts the voltage from the DC power supply 41 and varies the drive current supplied to the lamp 31 in accordance with the pulse signal from the pulse generation circuit 45. As a result, the lamp 31 is driven to blink at a predetermined cycle, emitting test light with pseudo-fluctuations. The amplifier circuit 43 can be composed of, for example, a boost circuit and a chopper circuit that interrupts the drive current supplied from the boost circuit to the lamp 31 in accordance with the pulse signal from the pulse generation circuit 45.

[0030] Incidentally, in the test apparatus of this embodiment, as described above, a glass lens 23 equipped with a filter layer 23A that transmits light of the main wavelength (ΔλIRm) is positioned in front of the halogen lamp 31. Furthermore, the glass lens 23 has the filter layer 23A partially provided in the center of the lens, and the peripheral part of the quartz lens transmits ultraviolet wavelength (ΔλUV). However, since the area ratio of the peripheral part of the lens that transmits ultraviolet light is 10%, if the lighting time per cycle is short, the amount of ultraviolet light emitted from the lens will be small, and there is a risk that the test apparatus under test will not be able to detect the ultraviolet light contained in the test light.

[0031] Therefore, in this embodiment, taking into account the fluctuations of the hydrogen flame, the blinking period of the halogen lamp 31 is set to, for example, 0.2s on - 0.1s off (seconds). This blinking period can be achieved by setting the period T of the pulse signal output from the pulse generation circuit 45 to 0.3s and the duty cycle to 2T / 3. Here, the period T of the pulse signal is not limited to 0.3s and may be changed as appropriate depending on the detection conditions of the flame detector and the environment in which the flame detector is installed.

[0032] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, although halogen lamps are used in the above embodiments, halogen lamps such as xenon lamps and LED lamps, or heat sources such as infrared heaters may also be used. Furthermore, in the above embodiment, a pulse generation circuit that generates a pulse signal with a fixed period is provided in the drive circuit that lights the lamp, and the current supplied to the lamp is periodically cut off to make the lamp blink. However, a means for changing the period of the pulse signal (for example, a volume button) may be provided so that the operator can change the blinking period of the lamp. Also, in this application, in addition to cutting off the current, for example, a small amount of current may be continuously supplied to reduce the brightness compared to when the lamp is lit. In this case, the blinking corresponds to the increase or decrease in the brightness of the lamp, and a test light that takes fluctuations into account can be emitted.

[0033] Furthermore, although the above embodiment described the application of the present invention to a tester for a flame detector that detects fires caused by hydrogen leaks, the present invention is not limited to flame detectors that detect fires caused by hydrogen leaks, but can be used in testers that are generally used for flame detectors that detect the occurrence of a fire by detecting the wavelengths contained in the flame. Furthermore, although the above embodiment described the case where the device is applied to a portable testing device with a handle, it is also possible to apply it to a non-portable testing device. [Explanation of symbols]

[0034] 10. Operational testing device (tester) for flame detectors 11. Tester unit (main unit case) 11a Male thread part 11b Fin 12 Lens section 13 Case back 14 Handle 15 Switch buttons 16A,16B Legs 21 Lens retaining nut 22 Reflectors 23 Glass lenses 23A Filter layer 23B Uncoated portion of the filter layer 24 Lens Cover 24a Threaded part 24b fins 24c Right angle step 25 Insulation Spacers 26 O-rings 31 Halogen lamp 41 DC power supply 42 CPU (Control Means) 43 Amplifier circuit (drive circuit) 44 Switch Circuits 45. Pulse generation circuit 46 Voltage monitoring circuit 47 On / Off Button 48 Indicator light 50 Flame detectors

Claims

1. A flame detector operation test device that incorporates a lamp, a drive circuit that lights the lamp by supplying current to it, and a control means, and is capable of emitting light of a predetermined wavelength in a certain direction, The control means is configured to increase or decrease the current supplied from the drive circuit to the lamp at a predetermined interval to cause the lamp to blink periodically, and the operating time during the blinking is set to be longer than the off time, characterized in that this is an operational test device for a flame detector.

2. The flame detector operation test device according to claim 1, characterized in that the ratio of the lighting time to the off time is set to 2:

1.

3. The flame detector operation test apparatus according to claim 2, characterized in that the control means is configured to blink the lamp at a period of 0.3 seconds.

4. The lamp is equipped with a lens positioned in front of it, The lens is provided with a filter layer in at least part of it that transmits light in a predetermined wavelength range corresponding to the wavelength detected by the flame detector under test, and blocks or attenuates light outside the predetermined wavelength range. The flame detector operation test apparatus according to any one of claims 1 to 3, characterized in that the filter layer is configured to transmit at least a portion of the wavelength range of infrared rays or ultraviolet rays.

Images