JP2012242307A - Thunder stroke test device, thunder stroke test system, and thunder stroke test method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thunder stroke test device, a thunder stroke test system, and a thunder stroke test method capable of eliminating trouble in imaging or electricity leakage caused by dew condensation, etc., enhancing efficiency in cooling a test piece, and reducing a cost.SOLUTION: A thunder stroke test device 1 includes: a dark box 31 for storing a test piece 1 to which a thunder stroke current is supplied; cameras 32 arranged in the dark box 31 and imaging the test piece 1; and a gas sprayer 33 for spraying cooled gas along both of surfaces, i.e., an imaging surface 1A of the test piece 1 to be imaged by the cameras 32 and a surface 1B on the opposite side of the imaging surface 1A of the test piece 1.

Description

  The present invention relates to a lightning strike test apparatus, a lightning strike test system, and a lightning strike test system for performing a test relating to lightning resistance performance by applying a lightning strike current to a specimen.

A wing constituting an aircraft body generally has a hollow structure, and a wing surface panel forming a wing surface is fastened to a structural member inside the wing by a fastener member (fastener).
In addition to this, structural members other than the wing surface panel and members for fixing the equipment are also fastened by fastener members inside the wing and the fuselage.

  By the way, in an aircraft, it is necessary to take all possible measures against lightning for explosion protection. When lightning occurs in an aircraft and a large current flows through a wing surface panel such as a main wing or a structural member, a part or all of the current flows in a fastening portion formed by the fastener member. When the current value exceeds the limit value of the allowable passage current at each fastening portion, a discharge called an electric arc (or thermal spark) is generated (hereinafter referred to as an arc in this specification). This is a phenomenon in which a rapid temperature rise occurs at the local part of the fastening interface of the member mainly composed of a conductive member that constitutes the fastening part due to the current passing through the fastening part, and a discharge is generated in the atmosphere in the vicinity. In this case, the molten material, which is called hot particles, is scattered from the melted portion. In general, the inner space of the wing also serves as a fuel tank. During this lightning strike, the generation of an arc and the hot particles that scatter from the arc are suppressed by suppressing the arc generation or sealing the arc. It is necessary to prevent explosions and prevent explosions by avoiding contact with combustible fuel vapor. Here, the part where the flammable fuel vapor may exist is a surge tank (such as a vent scoop or a burst disk) installed in the fuel tank, generally on the wing tip side of the fuel tank, inside the wing and the fuselage. Inside the tank) and inside the fuel system equipment.

  In order to ensure the safety of an aircraft, for example, a test assuming a lightning strike is performed on a portion where a plurality of members are fastened by the above-described fastener members. In such a lightning strike test, a specimen simulating airframe parts is installed in a dark box, and the lightning strike current is passed through the specimen from the lightning strike current generating means through a feeder line. A technique is generally used in which the specimen is photographed with a camera in a dark box and the presence or absence of an abnormality related to arc is confirmed based on the photographed image (captured image).

Japanese Patent No. 3595913

  Although the above-mentioned lightning strike test is performed at room temperature, from the viewpoint of assuming all operating conditions of the aircraft, by cooling the specimen to a high altitude to the outside air temperature (about −60 ° C.) during flight, It is desirable to conduct a lightning strike test that simulates the environment in flight at altitude.

  On the other hand, tests assuming a cryogenic environment during flight are also being conducted on aircraft, rockets, satellites, and other spacecraft. For such a test, for example, as in Patent Document 1, a cooling device including a chamber for accommodating a specimen and a cooling heat exchanger attached to the specimen is used.

When a specimen is cooled with such a heat exchanger for cooling, when a lightning strike test is performed by simulating a high altitude, there are the following problems.
That is, when a heat exchanger is used as a means for cooling the specimen, there is a problem that the cooling efficiency is not good. In other words, since it is necessary to photograph the entire surface of one of the specimens, a heat exchanger can only be attached to the other surface of the specimen, so the temperature difference between the imaging surface of the specimen and the cooling surface becomes large. Cooling takes a long time. In addition, moisture in the atmosphere may be condensed by contact with the cooled specimen, and condensation and frost formation may occur. Therefore, photography may not be performed accurately. Condensation and frosting may cause electric leakage during energization of the specimen. Furthermore, if a heat exchanger is attached to the specimen, there is a high risk of leakage through the metal member used in the heat exchanger.

  On the other hand, instead of using a heat exchanger, the entire chamber including the specimen may be cooled to a very low temperature by cooling the shroud installed in the vacuum chamber with liquid nitrogen. However, in this case, there is a possibility that shooting and recording cannot be performed because the temperature deviates from the operating temperature range of the camera. When a special camera capable of photographing even in a cryogenic region is used, the apparatus cost increases.

  The present invention has been made on the basis of such a problem, and there is no trouble in photographing due to condensation or the like, and there is no electric leakage, and the lightning test apparatus and the lightning test capable of reducing the cost with a high cooling efficiency of the specimen. It is an object to provide a system and a lightning strike test method.

  For this purpose, the lightning strike device of the present invention comprises a dark box that houses a specimen to which a lightning strike current is supplied, a photographing means that is installed in the dark box and photographs the specimen, and a specimen that is photographed by the photographing means. A gas sprayer that blows the cooled cooling gas is provided along both the imaging surface and the surface opposite to the imaging surface of the specimen.

  According to the present invention, temperature unevenness on both sides of the specimen is suppressed, and the specimen can be quickly cooled to a very low temperature, so that a test at a cryogenic temperature can be performed in a short time. In addition, since the surface of the specimen is kept dry by spraying the dry cooling gas on the specimen, it is possible to eliminate condensation and frost due to condensation of moisture in the atmosphere in contact with the specimen. it can. Accordingly, the test can be performed without any trouble based on the photographed image that accurately represents the photographing surface of the specimen. Since there is no condensation or frosting and no additional components such as a heat exchanger attached to the specimen can be used, the risk of leakage can be eliminated.

Further, since the cooling gas is blown onto the specimen, the temperature in the dark box is not lowered uniformly, and the temperature of the imaging means is not lowered like the temperature of the specimen. In other words, since the photographing means is not directly cooled, it is possible to photograph using a general camera (photographing means) that is not a special camera for cryogenic use, and condensation or frosting on the lens provided in the photographing means is possible. Can also be prevented.
From the above, it is possible to accurately and safely perform a lightning strike test at a cryogenic temperature simulating a high altitude environment, shorten the cooling time of the specimen, and use a general camera. Can be.

In the present invention, in the dark box, a gas sprayer is provided on one end side of the specimen, and an exhaust means for discharging the cooling gas that has passed through the specimen to the outside of the dark box is provided on the other end side of the specimen. It is preferable.
Here, the exhaust means is, for example, an opening (exhaust port) provided in the dark box. Alternatively, the exhaust means may include an exhaust port and a forced exhaust device such as a fan.

  According to the present invention, since the cooling gas blown from one end side of the specimen is quickly discharged from the other end side of the specimen, the entire dark box is not cooled, and only the specimen and its vicinity are local. Cooling more reliably. As a result, the temperature of the photographing means can be kept at a temperature close to room temperature.

  Furthermore, by exhausting the cooling gas, generation of haze due to condensation of moisture in the air in the dark box can be prevented. Therefore, the test can be performed based on a clearer and more accurate captured image.

  In the present invention, it is preferable that the exhaust means has a labyrinth flow path for deriving the cooling gas, and the labyrinth flow path has a plurality of light shielding members intersecting with the deriving direction of the cooling gas.

  According to the present invention, since the light beam having a straight traveling property is shielded by the light shielding member of the labyrinth flow path, light leakage from the exhaust port can be surely prevented as compared with the case where a dark curtain or the like is provided at the exhaust port. This makes it possible to clearly photograph an arc (thermal spark) that may occur at the fastening interface of the specimen during a lightning strike. Further, since the cooling gas can be discharged smoothly as compared with the case where a black curtain or the like is used, the temperature drop of the photographing means due to the cooling gas remaining in the dark box can be minimized.

In the present invention, it is preferable that the labyrinth channel leads the cooling gas downward in the vertical direction, and the light shielding member is inclined to the side that guides the cooling gas downstream.
According to the present invention, the natural discharge due to the gas atmosphere density difference inside and outside the dark box is promoted by the inclination of the light shielding member, so that the cooling gas can be discharged smoothly without using forced exhaust means. It becomes.

In the present invention, it is provided with a supply pipe for supplying a cooling gas from the outside of the dark box into the dark box, the gas sprayer includes a spray pipe connected to the supply pipe, and the supply pipe and the spray pipe are abutted against each other. The first flange which is one of the supply pipe and the spray pipe is provided with a plate along the surface opposite to the second flange side which is the other, and the second flange and the plate, It is preferable that the first flange is fastened by a fastening member provided with an elastic washer having elasticity.
It is preferable that the elastic washer is provided at both ends of the fastening member.

In the present invention, it is preferable that the supply pipe and the plate are made of a conductive material, the spray pipe is made of a non-conductive material, and the flange of the spray pipe is the first flange.
That is, between the supply pipe and the spray pipe, the flange of the spray pipe formed from a non-conductive material that is more easily damaged than the supply pipe is sandwiched between the second flange and the plate as the first flange. Is preferred.
According to the present invention, the gas sprayer employs a pipe formed from a nonconductive material to prevent leakage, and between the pipe formed from the nonconductive material and the pipe formed from the conductive material. The problem arising from the difference in shrinkage ratio can be overcome.

  In the present invention, it is preferable that a hole having a diameter larger than the outer diameter of the fastening member is formed in the first flange.

  The lightning strike test system of the present invention includes a lightning strike current generator that generates a lightning strike current, a lightning strike test device, and a control device that controls the lightning strike test device. The lightning strike test apparatus comprises a dark box that houses a specimen to which lightning current is supplied, a photographing means that is installed in the dark box and photographs the specimen, a photographing surface of the specimen photographed by the photographing means, and a photographing surface of the specimen A gas sprayer for spraying the cooled cooling gas is provided along both the opposite surface and the opposite surface.

  In the lightning strike test system of the present invention, it is preferable to include a temperature measuring means having a temperature sensor that is attached to the specimen and detects the temperature of the specimen, and a signal processing section that processes a detection signal from the sensor. The temperature sensor and the signal processing unit are connected by a connector that can be inserted and removed.

  In this invention, the temperature of the specimen is measured by the sensor, and after the specimen temperature reaches a predetermined set temperature, the connector is pulled out before the lightning strike current is supplied to the specimen, and the sensor and signal processing are performed. Separate the part. For this reason, since it becomes possible to give a lightning strike current to a specimen cooled to a desired temperature without damaging the signal processing unit due to the lightning strike current, it is possible to accurately perform a lightning strike test at an extremely low temperature. .

In the lightning strike test system of the present invention, it is preferable that the lightning strike current generator has a plurality of current waveform pattern generation circuits for generating different current waveform patterns.
According to the present invention, various lightning strike currents in which a plurality of current waveform patterns are combined can be generated.

In the lightning strike test system of the present invention, a lightning strike waiting time set in advance is counted starting from a lightning strike instruction input unit to which an instruction to supply a lightning strike current to the specimen is input and an input to the lightning strike instruction input unit. A lightning strike execution device having a timekeeping unit, and a trigger device for timing a preset time according to the lightning strike standby time, triggered by the input to the lightning strike instruction input unit, and operating the imaging means at the end of the timekeeping It is preferable.
According to the present invention, the time measured by the trigger device is set according to the lightning strike standby time, so that the photographing of the specimen immediately after the lightning can be automated.

  In addition, the lightning strike test method of the present invention is a test object housed in a dark box in which a photographing means is installed, a surface of the specimen photographed by the photographing means, and a surface opposite to the photographing surface of the specimen. A cooling gas is sprayed along both of the above, and after the specimen is cooled by the cooling gas, a lightning current is supplied to the specimen, and the specimen is photographed by photographing means.

  In the lightning strike test method of the present invention, it is preferable to discharge the cooling gas that has passed through the specimen to the outside of the dark box.

  In the lightning strike test method of the present invention, the temperature of the specimen is measured by a sensor attached to the specimen, and after the specimen temperature reaches a predetermined set temperature, a lightning current is supplied to the specimen. It is preferable to disconnect the sensor and the signal processing unit by unplugging the connector that connects the sensor and the signal processing unit that processes the detection signal from the sensor before.

  In the lightning strike test method of the present invention, a preset lightning strike standby time is counted from the time of input to the lightning strike input unit where an instruction to supply a lightning current to the specimen is input, and the test is provided at the end of the timing. While energizing the specimen with a lightning strike current, it is preferable to measure a preset time according to the lightning strike standby time in response to an input to the lightning strike instruction input unit, and operate the imaging means at the end of the time measurement.

According to the present invention, there is no hindrance to photographing due to dew condensation or the like, and there is no leakage, and the cooling efficiency of the specimen is high and the cost can be reduced.
In addition, since a gas is used for cooling, unlike the case where a specimen is cooled by mounting a solid cooler on the specimen, it is possible to easily deal with specimens of various shapes.

It is a figure showing a schematic structure of a lightning strike test system concerning a 1st embodiment of the present invention. It is a perspective view of the lightning strike test device of a 1st embodiment. It is a figure which shows an example of the waveform pattern of a lightning strike current. Each section of A to D has a different scale of the time axis. It is sectional drawing which shows the lightning strike test apparatus of 2nd Embodiment. FIG. 5 is a view taken in the direction of arrows V-V in FIG. 4. It is sectional drawing of the lightning strike test apparatus of 3rd Embodiment. It is sectional drawing of the lightning strike test apparatus of 4th Embodiment. It is a VIII-VIII line arrow directional view of FIG. It is a figure which shows piping of the gas sprayer which can be applied to the lightning strike test apparatus of each said embodiment. It is sectional drawing which shows the connection part of piping of the gas sprayer of FIG. 9, and gas supply piping. It is sectional drawing which shows the example of improvement of FIG.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. In the following description, the same components as those described before are denoted by the same reference numerals, and the description thereof is simplified or omitted.
[First Embodiment]
A lightning test system 100 shown in FIG. 1 includes a lightning current generator 2 for supplying a lightning current to a specimen 1, a lightning test apparatus 3 having an imaging means for the specimen 1, and a gas storage tank for storing a cooling gas. 4, a cooling gas is prepared using the gas in the gas storage tank 4, a cooling gas preparation / supply device 5 that supplies the cooling gas to the lightning strike test device 3, and a control chamber 6 that controls the entire lightning strike test system 100. And.

  Further, the lightning strike test system 100 is provided with a temperature sensor 101 that is mounted on the specimen 1 and detects the temperature of the specimen 1 and a temperature sensor 102 that detects the temperature of the cooling gas in the cooling gas preparation / supply device 5. It has been. For the temperature sensors 101 and 102, for example, thermocouples are used.

  The control room 6 controls the lightning strike test device 3 and the cooling gas preparation / supply device 5 to photograph and record the specimen 1 and display the photographed image on a monitor (not shown), and lightning current generation. A lightning strike control system 62 that controls the device 2 and oscilloscopes 631 to 633 that measure the current waveform of the measured lightning strike current are included.

The recording / display device 61 includes a signal processing unit 611 that processes the detection signals from the temperature sensors 101 and 102.
The lightning strike control system 62 includes a lightning strike execution device 621 that supplies a lightning strike current to the specimen 1. The lightning strike execution device 621 is set in advance with a lightning strike instruction switch 621A as a lightning strike instruction input unit to which an instruction to supply a lightning strike current to the specimen 1 is input, and when the lightning strike instruction switch 621A is turned on. And a timer unit 621B for measuring the lightning strike standby time. The lightning strike standby time can be set to any time.
A trigger device 104 that is linked to the lightning strike switch 621A of the lightning strike execution device 621 is connected to the lightning strike control system 62 with an optical fiber cable.
The trigger device 104 includes a timer 104 </ b> A that measures a photographing standby time that is set in advance according to the lightning strike standby time in the lightning strike execution device 621. The photographing standby time is determined so that the shutter of the camera 32 is opened immediately before the lightning strike current flows in consideration of the lightning strike standby time set in the lightning strike execution device 621.

  The temperature sensor 101 and the signal processing unit 611 constitute temperature measuring means for measuring the temperature of the specimen 1. The temperature sensor 101 and the signal processing unit 611 are connected by a connector 105 that can be inserted and removed. Further, the temperature sensor 102 and the signal processing unit 611 constitute temperature measuring means for measuring the temperature of the cooling gas. The temperature sensor 102 and the signal processing unit 611 are connected by a connector 106 that can be inserted and removed.

The lightning strike current generator 2 generates a plurality of current waveform patterns connected to the capacitors 211 to 213 via the control switches 221 to 223, respectively, and a plurality of large-capacity capacitors 211 to 213 for accumulating electric charges as a lightning strike current. Devices 231 to 233. This lightning strike current generator 2 is connected to a lightning strike control system 62. The current waveform pattern generation devices 231 to 233 generate a plurality of different waveform patterns, for example, four waveform patterns A to D. Note that the capacitance of the capacitor 211 can be switched, and the current waveform pattern generation device 231 generates either the waveform pattern A or the waveform pattern D shown in FIG. Is done.
Each on / off of the control switches 221 to 223 is switched by remote control by the lightning strike control system 62.

As shown in FIG. 2, the lightning strike test apparatus 3 includes a dark box 31 that houses the specimen 1, and two cameras 32 (only one is shown in FIG. 1) as photographing means installed in the dark box 31. A gas sprayer 33 provided above the specimen 1 is provided. The camera 32 is arranged with a predetermined focal length with respect to the specimen 1. That is, the specimen 1 and the camera 32 are arranged on one end side and the other end side of the dark box 31, respectively.
A trigger device 104 is connected to the camera 32, and the camera 32 is operated by the trigger device 104. As described above, since the trigger device 104 and the lightning strike control system 62 are optically connected by the optical fiber cable, it is possible to prevent leakage through the camera 32 during the lightning strike. For this reason, unlike the connection between the temperature sensors 101 and 102 described later and the signal processing unit 611, it is not necessary to disconnect before lightning strike.

  The specimen 1 is simplified in illustration, but is a panel in which a plate-like member simulating a blade surface panel and a fastener member through which a structural member inside the wing and the plate-like member simulating in the thickness direction penetrate. It is a shape. The specimen 1 is arranged along a plane orthogonal to the direction connecting the one end side and the other end side of the dark box 31 (same as the shooting direction by the camera 32). The specimen 1 to be tested by the lightning strike test apparatus 3 is not limited to a plate member simulating a blade surface panel and a structural member inside the blade, and may be of any shape and structure.

  Near the end of the specimen 1, a power supply line 11 to which a lightning current current is supplied from the lightning current generator 2 is connected. A ground wire 12 is connected in the vicinity of the end opposite to the side to which the feeder line 11 is connected in the specimen 1.

  As the camera 32, for example, a commercially available general digital camera can be used. The camera 32 is installed toward the plate surface (imaging surface 1A) of the specimen 1.

  The gas sprayer 33 is a resin cylinder extending along the upper end surface 1 </ b> C of the specimen 1. Cooling gas is supplied into the gas sprayer 33 from the cooling gas preparation / supply device 5 through a metal supply pipe 51 connected to one end of the gas sprayer 33. A number of holes 331 (FIG. 9) are formed at positions facing the upper end surface 1 </ b> C of the specimen 1 in the gas sprayer 33. When the cooling gas is ejected toward the specimen 1 from these holes 331, the cooling gas is sprayed along the entire surface of the imaging surface 1A of the specimen 1 and the surface 1B opposite to the imaging surface 1A. It is done. In addition, the slit along the longitudinal direction of the gas sprayer 33 may be formed instead of the many holes 331.

  Next, a lightning strike test method for the specimen 1 using the lightning strike test system 100 will be described. First, the cooling gas is adjusted to the cooling gas set temperature by controlling the cooling gas preparation / supply device 5 by the recording / display device 61, and the cooling gas is adjusted to the opposite side of the imaging surface 1A of the specimen 1 by the gas sprayer 33. The specimen 1 is cooled by spraying along both of the surfaces 1B. The temperature of the specimen 1 during cooling is measured by the temperature sensor 101 and the signal processing unit 611.

Since the specimen 1 is cooled from both sides, temperature unevenness is unlikely to occur on both sides of the specimen 1, so that the specimen 1 is rapidly cooled to a very low temperature, for example, −60 ° C. or lower.
Further, since the density of the cooling gas is larger than the density of the atmosphere in the dark box 31, the flow of the gas flow along both surfaces of the specimen 1 is promoted by blowing the cooling gas from above the specimen 1. For this reason, the cooling gas flows smoothly along the surface of the specimen 1.

  Here, as an example of the flow rate of the cooling gas and the temperature of each part at the time of the test, the cooling gas flow rate is 50 kg / h, the temperature of the cooling gas ejected from the gas sprayer 33 is −95.8 ° C., and the specimen 1 is −90.1 ° C., and the temperature around the camera 32 is 9.5 ° C. At this time, the depth L1, the width L2, and the height L3 of the dark box 31 are 930 mm, 300 mm, and 600 mm, respectively. As an example of the cooling time of the specimen, when the data in the case of a tape-like specimen (width 475.5 mm, height 25.4 mm, thickness 3 mm) is shown, the specimen reaches the above temperature at the above gas flow rate. The time is 9 minutes 41 seconds.

  When the temperature of the specimen 1 measured by the temperature sensor 101 and the signal processing unit 611 reaches a predetermined set temperature (extremely low temperature), the connectors 105 and 106 are disconnected as described below, and lightning is performed. .

  After the temperature of the specimen measured by the temperature sensor 101 and the signal processing unit 611 reaches the set temperature, the connector 105 is disconnected before the lightning current is supplied to the specimen 1, and the temperature attached to the specimen 1 The sensor 101 and the signal processing unit 611 are separated. Thereby, it is possible to prevent the signal processing unit 611 from being damaged due to the leakage of the lightning current supplied to the specimen 1. In order to prevent lightning current leakage through the metal supply pipe 51, the temperature sensor 102 and the signal processing unit 611 provided in the cooling gas preparation / supply device 5 are also disconnected before the lightning stroke. Separate. An electrical or mechanical means for automatically inserting and removing the connectors 105 and 106 may be provided. Depending on the lightning strike standby time, the connectors 105 and 106 may be disconnected after the lightning strike instruction switch 621A is turned on.

In carrying out the lightning strike, the lightning strike current is supplied to the specimen 1 by controlling the lightning strike current generator 2 with the lightning strike control system 62.
The lightning strike instruction for carrying out the lightning strike is performed by manually turning on the lightning strike instruction switch 621A of the lightning strike execution device 621 after visually confirming that the specimen 1 is at a very low temperature on the monitor of the recording / display device 61. Alternatively, the lightning strike instruction switch 621A is automatically turned on by the lightning strike control system 62 when the specimen 1 is at a very low temperature by the cooperation processing of the signal processing unit 611 and the lightning strike control system 62. Also good.
When the lightning strike instruction switch 621A is turned on, the timing unit of the lightning strike execution device 621 measures the lightning strike standby time starting from the time when the lightning strike instruction switch 621A is turned on, and the trigger device 104 triggers. The trigger device 104 measures the imaging standby time when the lightning strike instruction switch 621A is turned on.

  At the end of timing of the lightning strike standby time, the control switches 221 to 223 are sequentially turned on and off by the lightning strike control system 62, so that a lightning strike current in which a plurality of waveform patterns are combined as shown in FIG. . In the section A in FIG. 3, the control switch 221 is turned on and the other control switches 222 and 223 are turned off, thereby forming a circuit including the capacitor 211, the current waveform pattern generation device 231, and the specimen 1. Is done. At this time, the lightning strike current having the waveform pattern A generated by the current waveform pattern generation device 231 is supplied to the specimen 1.

  Similarly to the above, in the section B, the control switch 222 is turned on and the other control switches 221 and 223 are turned off, so that a circuit including the capacitor 212, the current waveform pattern generation device 232, and the specimen 1 is provided. Is formed, and a lightning strike current having a waveform pattern of B is supplied to the specimen 1. Thereafter, similarly, a C waveform pattern and a D waveform pattern are generated in the C section and the D section, respectively, and a lightning strike current in which the A to D waveform patterns are combined as shown in FIG. Supplied. Since the circuit is shared by the A waveform pattern and the D waveform pattern by switching the capacitance of the capacitor 211, a circuit similar to the A section is formed in the D section.

  The lightning strike current that has flowed through each circuit formed by turning the control switches 221 to 223 on and off is measured by a current measuring means provided for each circuit. The current measuring means corresponding to the circuit including the control switch 221 includes an oscilloscope 631 and a current transformer CT. Similarly, the current measuring means corresponding to the circuit including the control switch 222 includes an oscilloscope 632 and a current transformer CT. The current measuring unit corresponding to the circuit including the control switch 223 includes an oscilloscope 633 and a shunt resistor inserted in series with the circuit. The lightning strike current measured by these current measuring means is displayed / recorded by the recording / display device 61.

  By appropriately switching the control switches 221 to 223, lightning strike currents having various waveform patterns can be generated. The waveform patterns A to D may be used alone or in combination of two or more thereof. Moreover, the magnitude of the lightning strike current can be adjusted by changing the capacitances of the capacitors 211 to 213. The magnitude and waveform pattern of the lightning strike current are selected according to test conditions and standards.

On the other hand, the trigger device 104 operates the two cameras 32 at the end of the measurement of the photographing standby time. Since the shooting standby time set in the trigger device 104 is determined in consideration of the lightning strike standby time set in the lightning strike execution device 621, the shutter of the camera 32 is opened immediately before the lightning strike current flows, and the lightning strike current is The photographing surface 1A of the specimen 1 immediately after flowing can be photographed. The shooting timings of the two cameras 32 may be shifted simultaneously or slightly. Further, in one lightning strike on the specimen 1, one shooting may be performed by the two cameras 32, or a plurality of shootings may be performed. By shooting at different timings during a single lightning stroke, the generated arc can be captured more reliably.
In addition, as shown in FIG. 3, the lightning strike current is instantaneously generated in a very short time, and the specimen 1 is photographed instantaneously.

  Data of a photographed image of the specimen 1 photographed by the camera 32 is sent to the recording / display device 61. The recording / display device 61 records captured image data in a recording device and displays the captured image on a monitor. Based on the recorded and displayed photographed image, the lightning resistance performance of the specimen 1 at an extremely low temperature is tested. When the arc prevention that can occur at the fastening interface of the specimen 1 or the arc sealing is insufficient, the flash of the arc is reflected in the photographed image, so by evaluating the presence or absence of the flash and the state of the flash, The lightning resistance performance of the specimen 1 can be tested.

According to the first embodiment described above, the following effects can be obtained.
Since the specimen 1 is cooled from both sides by the cooling gas, temperature unevenness hardly occurs on the imaging surface 1A of the specimen 1 and the surface 1B on the opposite side, so the cooling effect of the specimen 1 is high. In addition, since the specimen 1 is cooled by using the cooling gas, it is unnecessary to attach the adjunct of the solid cooler (such as a heat exchanger) to the specimen 1, so that the specimen 1 was used for the solid cooler. Leakage through the conductive member can be prevented.
In addition, since the cooling gas is blown from above the specimen 1, a sufficient amount of the cooling gas flows uniformly along the entire surface of the specimen 1, so that temperature unevenness hardly occurs in the surface of the specimen 1. Even in this respect, the cooling effect of the specimen 1 can be increased. According to the lightning strike test system 100, a lightning strike test at an extremely low temperature can be performed in a short time.

Moreover, since the surface of the specimen 1 is kept dry by spraying the dried cooling gas, condensation and frost due to condensation of moisture in the atmosphere on the surface of the specimen 1 do not occur.
Furthermore, since the temperature in the dark box 31 does not drop uniformly by spraying the cooling gas onto the specimen 1, it is possible to prevent condensation and frost formation on the lens of the camera 32.
In this way, since no dew condensation or frosting occurs on the specimen 1 or the camera 32, the test can be performed without any trouble based on the photographed image that accurately represents the photographing surface 1A of the specimen 1. In addition, since no dew condensation or frost is generated on the specimen 1, electric leakage can be prevented.
Furthermore, since the temperature in the dark box 31 does not drop uniformly by blowing the cooling gas onto the specimen 1, the camera 32 and its surroundings do not become as low as the temperature of the specimen 1. Therefore, a general camera that is not a special camera for cryogenic use can be used as the camera 32. By eliminating the need for a special camera, the lightning strike test system 100 can be configured at low cost.
From the above, a lightning strike test under a cryogenic temperature simulating a high altitude environment can be performed accurately and safely at a low cost.

[Second Embodiment]
As shown in FIGS. 4 and 5, the gas sprayer 33 is provided above the specimen 1 in the dark box 71 of the lightning strike test apparatus 7 of the second embodiment. Further, a cooling gas exhaust means 72 is provided below the specimen 1 in the vertical direction. The exhaust means 72 includes an exhaust port 721 formed in a lower portion of the side surface 71A of the dark box 71 intersecting the plate surface direction of the specimen 1, and an exhaust for leading the cooling gas that has passed through the specimen 1 toward the exhaust port 721. A flow path 722.

As shown in FIGS. 4 and 5, a portion of the bottom surface 71 </ b> B of the dark box 71 excluding the lower portion of the specimen 1 is covered with a cover 73 having an L-shaped cross section. The exhaust passage 722 is formed by the side surface portion 73A of the cover 73 and the bottom surface 71B, the side surface 71A, the side surface 71C, and the side surface 71D of the dark box 71. The exhaust passage 722 guides the cooling gas along a direction (leading direction D) intersecting both the direction connecting the one end side and the other end side of the dark box 71 and the vertical direction.
In the vicinity of the exhaust port 721, an exhaust fan 74 serving as forced exhaust means is provided.

  The cooling gas introduced into the dark box 71 by the gas sprayer 33 passes through the specimen 1 and then flows along the outlet direction D through the exhaust passage 722 and is discharged from the exhaust port 721 to the outside of the dark box 71. . In addition, although the exhaust fan 74 is provided, the cooling gas can be quickly discharged, but the cooling gas can be naturally discharged even if the exhaust fan 74 is not provided.

  Since the cooling gas is discharged out of the dark box 71, only the specimen 1 and the vicinity thereof are reliably cooled locally without cooling the entire inside of the dark box 71. As a result, the temperature of the camera 32 can be maintained at a temperature close to room temperature, so that reliable operation of the general camera 32 that is not used for extremely low temperatures can be ensured.

  Furthermore, generation | occurrence | production of the haze by condensation of the moisture in the air in the dark box 71 can be prevented by exhausting cooling gas. In addition to prevention of condensation and frost as described in the first embodiment, generation of soot can be prevented, so that a test can be performed based on a clearer and more accurate photographed image.

[Third Embodiment]
As shown in FIG. 6, the exhaust means 78 in the third embodiment is continuous with the exhaust flow path 722 and the exhaust flow path 722 described above, and extends along the direction connecting the one end side and the other end side of the dark box 71. The labyrinth channel 781 for leading out the cooling gas and the exhaust port 782 for discharging the cooling gas led out by the labyrinth channel 781 out of the dark box 71 are provided.

  The labyrinth channel 781 includes a plurality of light shielding members 783A and 783B that are alternately provided on the opposing side wall 781A and side wall 781B of the labyrinth channel 781 in the derivation direction D (the depth direction of the dark box 71). These light shielding members 783A and 783B project from the side wall 781A and the side wall 781B along the direction orthogonal to the derivation direction D, respectively, to a position exceeding the central axis AA that bisects the opening dimension W of the labyrinth channel 781. It extends.

  Since the light beam having a straight traveling property is shielded by the light shielding members 783A and 783B, the light traveling toward the exhaust port 782 is attenuated. In particular, in this embodiment, the flow path is long in the depth direction of the dark box 71, and a large number of light shielding members 783A and 783B can be arranged. Light leakage from the mouth 782 can be prevented more reliably.

  Since the light shielding property in the dark box 71 is ensured by the labyrinth channel 781, clear imaging of an arc that can occur during a lightning strike is possible. Further, since the cooling gas can be discharged smoothly compared to the case where a black curtain or the like is provided at the exhaust port 782, the temperature drop of the camera 32 due to the cooling gas remaining in the dark box 71 can be minimized.

[Fourth Embodiment]
As shown in FIGS. 7 and 8, the exhaust means 81 of the fourth embodiment discharges the cooling gas that has passed through the labyrinth flow path 811 that guides the cooling gas downward in the vertical direction, and the labyrinth flow path 811. And an exhaust port 812. In the present embodiment, a cooling gas having a density larger than the density of the atmosphere outside the dark box 71 is used.
The labyrinth channel 811 is an extension of the flow FL of the cooling gas passing through the specimen 1 and is formed by the side surface portion 73A of the cover 73 and the bottom surface 71B, the side surface 71A, the side surface 71C, and the side surface 71D of the dark box 71. Yes. The labyrinth channel 811 includes light shielding members 811A and 811B extending in a direction intersecting with the derivation direction D.

The light shielding members 811A and 811B are alternately provided on the side surfaces 71C and 71A of the dark box 71. The light shielding member 811A extends from the side surface 71C of the dark box 71 in a direction obliquely intersecting the lead-out direction D. The front end P1 of the light shielding member 811A is on the lower side in the vertical direction than the base end Q1 of the light shielding member 811A. On the other hand, the light shielding member 811B extends on the side surface 71A of the dark box 71 from a position lower than the tip P1 of the light shielding member 811A in a direction obliquely intersecting the lead-out direction D. The front end P2 of the light shielding member 811B is on the lower side in the vertical direction than the base end Q2 of the light shielding member 811B. From the above, the light shielding members 811A and 811B are inclined to the side for guiding the cooling gas to the downstream side.
This promotes natural discharge due to the weight of the cooling gas. That is, natural discharge due to the difference in gas atmosphere density inside and outside the dark box 71 is easily performed. For this reason, it is possible to smoothly discharge the cooling gas without using the exhaust fan 74 (FIG. 6).

  Further, the cooling gas can be discharged smoothly even when the length of the labyrinth channel 811 in the outlet direction D is shorter than the length of the labyrinth channel 781 in the outlet direction D of FIG. The positions where the labyrinth channels 781, 811 and the like are provided in the dark box 71 can be appropriately changed according to the height, width, depth dimensions of the dark box 71 and the height, width, thickness dimensions of the specimen 1.

  The cooling gas guided by the light shielding members 811 </ b> A and 811 </ b> B is discharged from the exhaust port 812 formed on the side surface 71 </ b> A of the dark box 71. The location of the exhaust port 812 may be the bottom surface 71B of the dark box 71. Regardless of the position of the exhaust port 812, the effect of promoting discharge by the light shielding members 811A and 811B can be obtained.

Next, the piping connection structure of the cooling gas that can be applied to the lightning strike test apparatus of each of the above embodiments will be described.
FIG. 9 shows a gas sprayer 33 provided in a dark box (not shown). The gas sprayer 33 is made of a resin that is a non-conductive material. Since the gas sprayer 33 is close to the specimen 1, it is possible to prevent leakage of the specimen 1 during a lightning strike by forming it from a non-conductive material such as a resin. The gas sprayer 33 has a spray pipe 35 connected to the supply pipe 51 of the cooling gas preparation / supply device 5 (FIG. 1). The spray pipe 35 is also formed from a resin which is a non-conductive material.

  As shown in FIG. 10, the spray pipe 35 has a resin flange 350 (first flange) made of resin, and the supply pipe 51 has a metal flange 510 (second flange) made of metal. The resin flange 350 and the metal flange 510 are abutted against each other.

  On the resin flange 350, a metal plate 355 is disposed along a surface 350A opposite to the metal flange 510 side. The plate 355 is formed with a hole 355A through which the cylindrical portion 351 of the spray pipe 35 passes. The plate 355 and the metal flange 510 are fastened with the fastening member 38 sandwiching the resin flange 350 therebetween.

  Holes 355A and 510A in which the fastening member 38 is provided are formed in the plate 355 and the metal flange 510, respectively. These holes 355 </ b> A and 510 </ b> A are formed at a plurality of positions in the circumferential direction of the metal flange 510.

  The fastening member 38 includes a bolt 380 that passes through the holes 355A and 510A, and nuts 381 provided at both ends of the bolt 380. In addition, elastic washers 39 are provided between the plate 355 and the nut 381 at both ends of the fastening member 38 and between the metal flange 510 and the nut 381, respectively. As the elastic washer 39, a rubber washer formed of a rubber material, a spring washer, or the like can be used.

  When cooling gas is introduced into the dark box 71 from the cooling gas preparation / supply device 5 through the gas sprayer 33, the supply pipe 51 and the spray pipe 35 are cooled, and the metal flange 510 and the resin flange 350 are connected. Stress is generated between the metal flange 510 and the resin flange 35 due to the difference in shrinkage rate. Here, since the metal flange 510 and the resin flange 35 are fastened through the plate 355 and the fastening member 38 is provided with the elastic washer 39, the flanges 350 and 510 are allowed to slide during cooling. The That is, the relative positional deviation between the flanges 350 and 510 is allowed. In this way, since the difference between the shrinkage rates of the flanges 350 and 510 is absorbed, the stress of the spray pipe 35 and the supply pipe 51 can be reduced. Thereby, damage to the spray pipe 35 and the supply pipe 51 can be prevented.

  FIG. 11 shows an improved example of FIG. A hole 451 having a diameter larger than the outer diameter of the bolt 380 is formed in the resin flange (first flange) 450 of FIG. By forming such a hole 451, positioning of the spray pipe 35 and the supply pipe 51 when the plate 355 and the metal flange 510 are fastened becomes easy. Further, since the gap S is formed between the bolt 380 and the inner wall of the hole 451, the flanges 450 and 510 can be prevented from being damaged due to the difference in shrinkage rate.

  In each of the above-described embodiments, the cooling gas is blown from above the specimen 1, but the cooling gas may be blown from the side or the lower side of the specimen 1. For example, a gas sprayer is provided at a position corresponding to the side surface 1D (FIG. 2) of the specimen 1 so that the cooling gas flows from the side of the specimen 1 to the imaging surface 1A of the specimen 1 and the opposite surface 1B. And may be sprayed along both sides.

  Furthermore, in 2nd Embodiment etc., the structure which discharges the cooling gas sprayed along the both surfaces of the specimen 1 from the upper direction of the specimen 1 out of the dark box 71 from the exhaust port 721 provided in the lower part of the specimen 1 However, the present invention is not limited to the configuration in which the cooling gas blown from one end side of the specimen 1 is discharged from the other end side of the specimen 1 as described above. The cooling gas blown from may be discharged from an exhaust port formed in the bottom surface 71B (FIG. 4) of the dark box 71.

  Here, the blowing direction of the cooling gas, the position of the exhaust means, and the direction in which the cooling gas is led out in the exhaust means may be determined in consideration of the magnitude difference of the density difference between the cooling gas and the atmosphere. Unlike the above embodiments, when a cooling gas having a density lower than the density of the atmosphere is used, the cooling gas is blown along the specimen 1 by blowing the cooling gas from the lower side to the upper side of the specimen 1. Flows smoothly. In such a case, it is preferable to provide the exhaust means vertically above the specimen 1. Furthermore, if the derivation direction by the discharge means is a direction from the lower side to the upper side in the vertical direction, the cooling gas can be discharged smoothly.

  In the second embodiment and the like, the cooling gas exhaust passage is formed inside the dark box 71 including the wall surface (bottom surface 71B, side surfaces 71A, 71C) of the dark box 71. However, the exhaust passage is outside the dark box 71. It may be installed in.

Further, the number of cameras 32 used in the lightning strike test apparatuses 3 and 7 is not limited, and the specimen 1 may be photographed by one camera 32.
The camera 32 may be a silver salt camera, and in that case, the lightning resistance performance of the specimen 1 is tested based on a photograph that is a captured image.

  In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

DESCRIPTION OF SYMBOLS 1 Specimen 1A Image | photographing surface 1B The surface on the opposite side to an imaging surface 2 Lightning strike current generators 3, 7 Lightning strike test device 6 Control device 31, 71 Dark box 32 Camera (photographing means)
33 Gas sprayer 35 Spray piping (non-metallic piping)
38 Fastening member 39 Elastic washer 51 Supply piping 72, 78, 81 Exhaust means 100 Lightning strike test system 101, 102 Temperature sensor 104 Trigger device 104A Timer 105, 106 Connector 231-233 Current waveform pattern generator 350, 450 Resin flange (first Flange)
355 Plate 380 Bolt 381 Nut 510 Metal flange 611 Signal processing unit 621 Lightning strike execution device 621A Lightning strike instruction switch (lightning strike instruction input part)
621B Timekeeping section 721, 782, 812 Exhaust port 722 Exhaust flow path 781, 811 Labyrinth flow paths 783A, 783B, 811A, 811B Light shielding member D Lead-out direction

Claims (15)

A dark box containing a specimen to which lightning current is supplied;
An imaging means installed in the dark box for imaging the specimen,
A gas sprayer that blows a cooled cooling gas along both the imaging surface of the specimen imaged by the imaging means and the surface of the specimen opposite to the imaging surface; A lightning strike test device characterized by. In the dark box, the gas sprayer is provided on one end side of the specimen,
The lightning strike test apparatus according to claim 1, wherein an exhaust unit that discharges the cooling gas that has passed through the specimen to the outside of the dark box is provided on the other end side of the specimen. The exhaust means has a labyrinth flow path for deriving the cooling gas;
The lightning strike test apparatus according to claim 1, wherein the labyrinth flow path has a plurality of light shielding members intersecting with a direction in which the cooling gas is led out. The labyrinth flow path leads the cooling gas downward in the vertical direction;
The lightning strike test apparatus according to any one of claims 1 to 3, wherein the light shielding member is inclined to a side that guides the cooling gas downstream. A supply pipe for supplying the cooling gas from outside the dark box into the dark box;
The gas sprayer includes a spray pipe connected to the supply pipe;
The supply pipe and the spray pipe have flanges that are abutted against each other;
The first flange which is one of the supply pipe and the spray pipe is provided with a plate along a surface opposite to the second flange side which is the other,
The said 2nd flange and the said plate are fastened in the state which pinched | interposed the said 1st flange by the fastening member in which the elastic washer which has elasticity was provided. The described lightning strike test apparatus. The supply pipe and the plate are formed of a conductive material;
The spray pipe is formed of a non-conductive material;
The lightning strike test apparatus according to claim 5, wherein a flange of the spray pipe is the first flange.   The lightning strike test apparatus according to claim 5 or 6, wherein a hole having a diameter larger than an outer diameter of the fastening member is formed in the first flange. A lightning current generator for generating a lightning current,
A dark box that houses the specimen to which the lightning current is supplied, a photographing means that is installed in the dark box and photographs the specimen, a photographing surface of the specimen that is photographed by the photographing means, and the specimen A lightning strike test apparatus having a gas sprayer for blowing a cooled cooling gas along both the opposite surface to the imaging surface;
A lightning strike test system comprising: a control device that controls the lightning strike test device. A temperature sensor that is mounted on the specimen and detects a temperature of the specimen, and a temperature measuring means that has a signal processing unit that processes a detection signal from the sensor;
The temperature sensor and the signal processing unit are connected by a connector that can be inserted and removed. The lightning strike test system according to claim 8.   The lightning strike test system according to claim 8 or 9, wherein the lightning strike current generator has a plurality of current waveform pattern generation circuits for generating different current waveform patterns. A lightning strike execution apparatus having a lightning strike instruction input unit for inputting an instruction to supply a lightning strike current to the specimen, and a timing unit for measuring a preset lightning strike standby time from the time of input to the lightning strike instruction input unit When,
A trigger device that counts a time set in advance according to the lightning strike standby time in response to an input to the lightning strike instruction input unit and operates the imaging unit at the end of the time measurement. The lightning strike test system according to any one of the above. With respect to the specimen housed in the dark box in which the photographing means is installed, along both the photographing surface of the specimen photographed by the photographing means and the surface of the specimen opposite to the photographing surface Spray cooling gas,
After the specimen is cooled by the cooling gas, a lightning strike current is supplied to the specimen, and the specimen is photographed by the photographing means.   The lightning strike test method according to claim 12, wherein the cooling gas that has passed through the specimen is discharged to the outside of the dark box. Measure the temperature of the specimen by a temperature sensor mounted on the specimen and a signal processing unit that processes a detection signal from the temperature sensor,
After the temperature of the specimen reaches a predetermined set temperature, before the lightning current is supplied to the specimen, the connector for connecting the sensor and the signal processing unit is pulled out and the sensor and the The lightning strike test method of Claim 12 or 13 which isolate | separates from a signal processing part. Starting at the time of input to the lightning strike instruction input section where an instruction to supply lightning current to the specimen is input, the preset lightning strike waiting time is counted, and the lightning current is supplied to the specimen at the end of the timing. On the other hand,
The timing according to the lightning strike standby time is measured in response to an input to the lightning strike instruction input unit, and the photographing unit is operated at the end of the time measurement. The described lightning strike test method.

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