JP4369316B2 - Nondestructive inspection equipment - Google Patents

Description

  The present invention relates to a non-destructive inspection apparatus that non-destructively inspects an inspection object based on free vibration generated in the inspection object.

  In a conventional nondestructive inspection device such as a concrete structure, an excitation unit is used to hit the surface of an object to be inspected with a steel ball through a steel ball holding cap using a piezoelectric or magnetostrictive body. There is known a method for non-destructively inspecting the inside by detecting a free vibration excited by an inspection object at a receiving unit, converting it into a vibration waveform of an electric signal, and analyzing the vibration waveform. In this method, a method of avoiding reception of unnecessary vibration due to double strike by the excitation unit by synchronizing the reception period of the vibration waveform with the excitation operation of the excitation unit is disclosed (for example, see Patent Document 1). .

JP 2002-202293 A (paragraph numbers 0018 to 0020, 0024, 0035 and FIG. 1)

  In the conventional nondestructive inspection apparatus, the period for receiving vibrations by the receiving unit is determined in synchronization with the control signal supplied from the control unit to the excitation unit. A driving voltage is supplied to the excitation unit in synchronization with the control signal, the laminated electrical power generator rapidly expands, and the steel ball disposed at the tip thereof is blown off. At this time, the steel ball holding cap is pushed out against the elastic force of the helical spring connected to the steel ball holding cap that accommodates the steel ball, and the tip of the steel ball hits the striking surface. For this reason, the time until the receiving unit detects the excited vibration varies depending on the direction of the impact. That is, in the case of hitting upward against gravity and in the case of hitting downward along gravity, the potential energy due to the mass of the steel ball and the steel ball holding cap is reduced or added respectively, so the drive voltage is The time it takes to hit the striking surface after being supplied is different.

For this reason, it is necessary to take a sufficiently long time so that detection can be performed even if the reception period is changed depending on the hitting direction or the time until hitting is changed. In order to change the reception period depending on the direction, means for measuring the hitting angle and setting the reception period according to the angle is required. If a sufficiently long reception period is taken, there is a problem that unnecessary vibrations such as double hits and hammer sliding noise are mixed in, and the reliability of inspection is lowered.
In addition, in order to visually confirm the state of the striking surface, it is necessary for the inspector to check in close proximity to the object to be inspected, and workability is poor in inspection in high places, narrow places, dark places, etc. There was a problem.

  The present invention has been made to solve the above-described problems, and is capable of improving the reliability of inspection by preventing the mixing of unnecessary vibration signals due to double hitting of the inspection object. The purpose is to obtain an inspection device. Moreover, it aims at obtaining the nondestructive inspection apparatus which can test | inspect while checking the state of the striking surface of a determination target object visually.

The nondestructive inspection apparatus according to the present invention includes a vibration means for generating vibration by striking the surface of an inspection object with a striking body, a vibration control means for controlling the vibration means, and detecting vibration as a vibration signal. Vibration detecting means for detecting movement, detecting means for detecting that the hitting body has moved in the direction of hitting and has reached a predetermined position away from the initial position of the hitting body, and a detection signal is transmitted, and detection A reception signal control means for receiving a signal and transmitting a vibration signal for a preset time, and a diagnosis means for diagnosing the state of the inspection object based on the vibration signal transmitted from the reception signal control means. is there.

The present invention includes a vibration means for generating vibration by striking the surface of an inspection object with a striking body, a vibration control means for controlling the vibration means, a vibration detection means for detecting vibration as a vibration signal, Operation detection means for detecting that the impacting body has moved in the direction of applying the impact and has reached a position determined in advance and away from the initial position of the impacting body, and a detection signal to be set in advance. Since the reception signal control means for transmitting the vibration signal for a predetermined time and the diagnosis means for diagnosing the state of the inspection object based on the vibration signal transmitted from the reception signal control means, the inspection object is detected twice. It is possible to improve the reliability of the inspection by preventing the mixing of unnecessary vibration caused by hitting.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of the inspection apparatus main body, FIG. 2 is an explanatory view showing the position of the hammer, and FIG. 3 is a time chart of the operation of the inspection apparatus main body. In FIG. 1, an inspection apparatus main body 60 is placed on the striking surface 1 a of the inspection object 1. The inspection apparatus main body 60 that is a nondestructive inspection apparatus is configured as follows. The moving device 8 has a moving table 81 as a support structure supported by two casters 82 and 83 at the front and rear.

  The striking device 2 has a hammer 21, a coil 22, and a spring 23 as vibration means, and a striking detection sensor 24 as motion detection means. A hammer 21 made of a magnetic material is elastically supported by a spring 23 at a central portion of a cylindrical coil 22 so as to be movable in the vertical direction of FIG. 1 and is driven in the vertical direction by the electromagnetic force of the coil 22. The hit detection sensor 24 includes a light emitting element 241 and an optical sensor 242. The light emitting element 241 and the optical sensor 242 are disposed at positions facing each other with the hammer 21 in between. The striking device 2 is fixedly supported by being dropped into the center of the movable table 81.

  Further, the impact control device 3, the reception signal control device 4, the diagnostic display device 5, the start switch 6, and the vibration sensor 7 are mounted on the moving device 8. The hit control device 3 is controlled to start by the start switch 6, and the output side of the hit control device 3 is connected to the coil 22 of the hit device 2. The detection signal of the optical sensor 242 is output to the batting control device 3 and the reception signal control device 4. The vibration sensor 7 includes a vibration detection unit 71 and a caster 82. The vibration detection unit 71 is directly connected to the caster 82 on the near side perpendicular to the paper surface of the caster 82, and the vibration of the striking surface 1a is transmitted through the caster 82. To detect. The reception signal control device 4 outputs a control signal to the vibration sensor 7 and the diagnostic display device 5.

Next, the operation will be described.
In FIG. 1, when the inspection apparatus main body 60 is not inspecting, the hammer 21 is supported from above by a spring 23 as shown in FIG. 2A, and a predetermined gap is formed between the hammering surface 1a. Have. When the inspector depresses the start switch 6 and gives a trigger signal, the driving voltage Vi is applied from the impact control device 3 to the coil 22 once or a plurality of times at a constant cycle. When the drive voltage Vi is applied to the coil 22, a magnetic field is generated inside by the current flowing through the coil 22. The hammer 21 made of a magnetic material is driven downward in the coil 22 by the magnetic force of the generated magnetic field to the state shown in FIG. 2B, and strikes the striking surface 1a.

  In the initial state of FIG. 2A before the drive voltage Vi is applied to the coil 22, the light emitted from the light emitting element 241 is blocked by the hammer 21, and the light from the light emitting element 241 is detected by the optical sensor. 242 is not detected. When the driving voltage Vi is applied to the coil 22 and the hammer 21 slides downward, the light sensor 242 detects the light of the light emitting element 241 that has been blocked until then, and the hammer 21 has reached a predetermined position. To do.

  When the optical sensor 242 detects the light from the light emitting element 241, the detection signal of the optical sensor 242 is input to the impact control device 3, and the drive voltage Vi applied to the coil 22 is cut off. Even if the driving voltage Vi is cut off, the hammer 21 continues to slide downward due to the inertial force, but eventually the force of the spring 23 connected to the hammer 21 becomes greater than the inertial force, and the hammer 21 that has slid downward is upward. Is returned to the initial position, and the state shown in FIG. The striking force and striking cycle applied to the striking surface 1a can be arbitrarily controlled by adjusting the magnitude of the driving voltage Vi, the period of applying the driving voltage Vi, and the time of application by the striking control device 3.

  On the other hand, the vibration detection unit 7 detects free vibration generated inside the inspection object 1 excited by the hammer 21 via the striking surface 1a. The vibration detection unit 71 is directly connected to the caster 82, and detects the vibration of the striking surface 1a via a wheel of the caster 82, a bearing (not shown), and a bearing (not shown) to generate a vibration signal which is an electric signal. Convert and output. The vibration signal from the vibration detection unit 71 is input to the reception signal control device 4.

  When the light sensor 242 detects the light of the light emitting element 241, the detection signal of the light sensor 242 is also output to the reception signal control device 4, and the vibration signal from the vibration detection sensor 7 is sent to the diagnostic display device 5 for a preset period. To transmit. The diagnostic display device 5 performs a predetermined analysis on the input vibration signal to diagnose and display the presence or absence of an abnormality inside the inspection object 1.

  Here, the operation of the inspection, that is, the diagnosis will be described in more detail with reference to the time chart shown in FIG. At the same time as the trigger signal St is input to the impact control device 3 by the start switch 6 at time t0, the drive voltage Vi that rises in a step shape is applied from the impact control device 3 to the coil 22. When the drive voltage Vi is applied, a current flows through the coil 22 to generate a magnetic field therein, and the hammer 21 starts to slide downward. The hammer 21 continues to slide, and the light sensor 242 detects the light of the light emitting element 241 blocked by the hammer 21 at time tl, and outputs a detection signal Sd. In response to this detection signal Sd, the impact control device 3 stops outputting the drive voltage Vi to the coil 22 at approximately time t1.

  That is, the waveform Vi of the voltage applied to the coil 22 is a rectangular wave having a magnitude V and a time width (t1-t0). When the detection signal Sd is input to the time signal control device 4, the gate signal Sg is transmitted for a preset time Δt (= t 3 -t 1), and the vibration signal W from the vibration detection unit 71 is displayed as the diagnostic display device 5. Send to. The diagnostic display device 5 performs predetermined processing and analysis on the input vibration signal, determines whether or not there is an abnormality in the inspection object 1, and displays the result. The detection signal Sd is cut off when the hammer 21 returns.

  As described above, when the hammer 21 reaches a predetermined position, the light sensor 242 detects the light of the light emitting element 241 that has been blocked by the hammer 21, thereby receiving the vibration signal W from the vibration detection unit 71. Since the signal control device 4 is configured to transmit to the diagnostic display device 6, an unnecessary noise vibration signal mixed from the caster 82 and the inspection target 1 or an unnecessary vibration signal due to double hitting of the inspection target 1 is mixed. Thus, a highly reliable mobile nondestructive inspection apparatus can be obtained.

  Further, it is possible to transmit the vibration signal from the vibration detection unit 71 from the reception signal control device 4 to the diagnostic display device 6 at a certain timing after the impact without being influenced by the impact direction. In addition, it is not necessary to take a sufficiently long time to change the reception period depending on the direction of hitting or to allow detection even if the time until the hammer 21 hits the inspection object 1 is changed. The period can be set easily. Furthermore, since the hammer 21 is driven by the coil 22, the impacting body can be easily controlled.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram of an inspection apparatus main body showing Embodiment 2 of the present invention. In Embodiment 1 of FIG. 1, when the hammer 21 reaches a predetermined position, the light from the light emitting element 241 blocked by the hammer 21 is detected by the optical sensor 242, so that the vibration from the vibration detection unit 71 is detected. The transmission of the vibration signal from the reception signal control device 4 to the diagnostic display device 6 has been described. In this embodiment, the movement table 81 is equipped with a movement distance detection sensor, and the impact device 2, that is, the hammer 21 is moved. The distance is detected, and the hammering time of the hammer 21 is controlled according to the moving distance.

  In FIG. 4, the inspection apparatus main body 70 has a movement distance detection sensor 9, and this movement distance detection sensor 9 is mounted on a moving table 81 of the movement apparatus 8. The movement distance detection sensor 9 is connected to the wheel 83a of the caster 83 and detects the movement distance of the striking device 2 from the rotational speed of the wheel 83a. When the striking device 2 moves on the striking surface 1a, a trigger signal that is predetermined according to the moving distance is generated and given to the striking control device 3 to control the time of striking with the hammer 21. As the movement distance detection sensor 9, for example, a position detection sensor such as a rotary encoder or a resolver is used. Since other configurations are the same as those of the first embodiment shown in FIG. 1, the same reference numerals are given to the corresponding components and the description thereof is omitted.

The inspector inputs the inspection pitch to the hitting control device 3 in advance, and the driving voltage Vi is applied to the coil 22 from the hitting control device 3 when the moving distance output from the moving distance detection sensor 9 matches the inspection pitch. .
With the above configuration, the batting control device 3 is controlled so that the hammer 21 strikes when the moving distance coincides with the inspection pitch by continuously moving the inspection apparatus main body in one direction. Inspection can be automatically performed for each (pitch).
In this second embodiment, an inspector as shown in the first embodiment manually operates the start switch one by one for each inspection point, or performs an inspection at a preset fixed period. In contrast, it is possible to inspect at a fixed distance (pitch) according to the moving distance. Accordingly, the inspection object 1 can be automatically hit according to the movement distance, and the work efficiency can be improved.

Embodiment 3 FIG.
5 and 6 show a third embodiment of the present invention. FIG. 5 is a configuration diagram of a mobile nondestructive inspection apparatus, and FIG. 6 is a detailed configuration diagram of the inspection apparatus main body. In FIG. 5, the inspection apparatus main body 80 is rotatably supported by the support mechanism 13 via the movable joint 12. The inspector presses the caster 82 and the caster 83 of the inspection apparatus main body 80 through the support mechanism 13 against the downward striking surface 1a of the inspection object 1 from below. The inspector is configured to control the start of the inspection with the start switch 6 at hand and to operate the brake device 10 of the inspection apparatus main body 80 with the hand brake operation switch 101.

  Next, in the inspection device main body 80, the brake device 10 is mounted on the moving device 8 as shown in FIG. The brake device 10 applies a frictional force Fb (see FIG. 5) to the wheels 83a of the caster 83 of the moving device 8 by a brake shoe by operating the hand brake operation switch 101. Thereby, a brake is applied to the movement of the moving device 8.

  As described above, when the inspection apparatus main body 80 is inspected for the inspection object 1 whose striking surface 1a faces downward (for example, the lower surface of the viaduct floor), the inspection apparatus main body 80 is rotatably supported by the support mechanism 13 and the striking surface. While it is possible to move freely on la, on the other hand, when the inspection is performed with the position fixed, a pressing force applied from the support mechanism 13 to the inspection apparatus body 80 in the horizontal direction Fh (see FIG. 5). It is assumed that the inspection apparatus main body 80 moves easily and is difficult to inspect at a fixed point. However, since this embodiment is configured as described above, it can be easily inspected by the following procedure.

a. The inspection apparatus main body 80 is moved to the target position by the support mechanism 13.
b. The hand brake operation switch 101 is operated, the brake device 10 is operated, and the wheel 83a of the caster 83 is restrained.
c. The inspector pushes up the inspection apparatus main body 80 via the support mechanism 13 and presses it against the striking surface 1a.
d. At this time, a horizontal component force Fh (see FIG. 5) is generated in the inspection apparatus main body 80 by the pressing force of the inspection apparatus main body 80 against the striking surface 1a. However, since the frictional force Fb of the brake device 10 is larger, there is no possibility that the inspection device body 80 moves in the horizontal direction. Therefore, the inspector can press against the striking surface 1a without taking care to prevent the movement of the inspection apparatus main body 80.
e. The start switch 6 is operated to perform measurement.
f. After the inspection is completed, the hand brake operation switch 101 is turned off. The braking of the wheel 83a by the brake device 10 is released, and the inspection device main body 80 can freely move on the striking surface 1a of the inspection object 1.

  As described above, in the present embodiment, the inspection device main body 80 is rotatably supported by the support mechanism 13 and the brake device 10 is mounted. Therefore, the brake device 10 is operated at a point to be inspected by hand operation, It is possible to easily inspect the downward striking surface 1a. That is, there is no possibility that the vibration means moves during measurement, and even an inspection object having a downward surface can be easily inspected, and work efficiency can be improved.

  It should be noted that the hitting surface is not limited to the downward surface as described above, and even if it is vertical or upward as shown in FIG. 1, the same effect is obtained, and the inspection apparatus main body is inadvertently moved during the measurement. It is possible to improve the work efficiency by preventing this.

Embodiment 4 FIG.
FIG. 7 is a configuration diagram of an inspection apparatus main body showing Embodiment 4 of the present invention. In FIG. 7, the inspection apparatus main body 90 is configured by mounting on the moving apparatus 8 an imaging apparatus 30 and a display apparatus 31 that capture image information of the striking surface 1 a of the inspection object 1. When the moving device 8 moves on the striking surface 1a, the imaging device 30 captures an image of the striking surface 1a and transmits it to the display device 31 as a video signal. The display device 31 displays a video of the striking surface 1a based on the received video signal. Such an imaging device 30 and a display device 31 can be realized using, for example, a small camera and a small monitor device.

  With the above configuration, the inspection apparatus main body 90 is brought close to an inspection point set in advance, and the image captured by the imaging apparatus 30 is displayed on the display apparatus 31, whereby the state of the surface of the inspection object can be confirmed at hand. The position to be selected can be efficiently implemented. As described above, it is possible not only to diagnose an internal abnormality by vibration generated by the excitation of the hammer 21 but also to perform an inspection while checking the surface state in detail at hand. Therefore, in the inspection of the inspection object in a high place, a narrow place, a dark place, etc., it is easy to ensure work safety and improve work efficiency.

  In each of the embodiments described above, the hammer is driven by a coil as the striking body, but may be driven by another method such as a piezoelectric body or a magnetostrictive body.

  As described above, according to the nondestructive inspection apparatus of the present invention, the vibration means for generating vibration by striking the surface of the inspection object with a striking body, the vibration control means for controlling the vibration means, Vibration detection means for detecting vibration as a vibration signal, operation detection means for detecting the movement of the impacting body and transmitting the detection signal, reception signal control means for receiving the detection signal and transmitting the vibration signal for a predetermined time, and reception signal And diagnostic means for diagnosing the state of the inspection object based on the vibration signal transmitted from the control means, thereby preventing the introduction of unnecessary vibration due to double hitting of the inspection object and increasing the reliability of the inspection be able to.

  The vibration means, vibration detection means, and motion detection means are mounted on a moving means that can move the surface of the object to be inspected, so that inspection while moving is easy.

  Further, the moving means has a moving distance detecting means for detecting the moving distance of the vibrating means and transmitting a moving distance signal. The vibration control means controls the vibrating means based on the moving distance signal. The position of the hitting point on the surface of the inspection object is determined, and the inspection object can be automatically hit according to the moving distance, and the work efficiency can be improved.

  The moving means has a rotatable wheel, a structural member supported by the wheel, and a braking means for braking the wheel, and the vibration means, vibration detecting means, and operation detecting means are mounted on the structural member. Therefore, there is no fear that the vibration means moves during the measurement, the work is easy, and the work efficiency can be improved.

  The inspection object has a downward surface, and the moving means is supported by the support means so that the vibration means can strike the downward surface of the inspection object from below. Since it is a feature, even an inspection object having a downward surface can be easily inspected.

  Furthermore, since the moving means is equipped with an image pickup means for picking up an image of the surface of the inspection object, the inspection can be performed while checking the surface state at hand.

It is a block diagram of the test | inspection apparatus main body which is one Embodiment of this invention. It is explanatory drawing which shows the position of a hammer. It is a time chart of operation | movement of a test | inspection apparatus main body. It is a block diagram of the test | inspection apparatus main body which shows other embodiment of this invention. Furthermore, it is a block diagram of the mobile nondestructive inspection apparatus which shows other embodiment of this invention. It is a block diagram which shows the detailed structure of the test | inspection apparatus main body of FIG. Furthermore, it is a block diagram of the test | inspection apparatus main body which shows other embodiment of this invention.

Explanation of symbols

2 striking device, 3 striking control device, 4 received signal control device, 5 diagnostic display device,
7 vibration sensor, 8 moving device, 9 moving distance detection sensor, 10 brake device,
12 movable joints, 13 support mechanisms, 21 hammers, 24 impact detection sensors,
30 imaging device, 31 display device, 60, 70, 80, 90 inspection device main body.

Claims (6)

A vibration means for generating vibration by striking the surface of the inspection object with a striking body, a vibration control means for controlling the vibration means, a vibration detection means for detecting the vibration as a vibration signal, and the striking Motion detecting means for detecting that the body has moved in the direction of applying the hitting and has reached a position determined in advance and away from the initial position of the hitting body, and receiving the detection signal; Non-destructive comprising: a reception signal control means for transmitting the vibration signal for a preset time; and a diagnosis means for diagnosing the state of the inspection object based on the vibration signal transmitted from the reception signal control means Inspection device. 2. The nondestructive inspection apparatus according to claim 1, wherein the vibration means, the vibration detection means, and the motion detection means are mounted on a moving means capable of moving the surface of the inspection object. . The moving means includes a moving distance detecting means for detecting a moving distance of the vibrating means and transmitting a moving distance signal, and the vibration control means controls the vibrating means based on the moving distance signal. The nondestructive inspection apparatus according to claim 2, wherein the position of the hitting point on the surface of the inspection object is determined by control. The moving means includes a rotatable wheel, a structural member supported by the wheel, and a braking means for braking the wheel. The vibration means, the vibration detecting means, and the motion detecting means are provided on the structural member. The nondestructive inspection apparatus according to claim 3, wherein the nondestructive inspection apparatus is mounted. The inspection object has a downward surface, and the moving means is supported by a support means so that the vibration means can strike the downward surface of the inspection object from below. The nondestructive inspection apparatus according to claim 4, wherein the nondestructive inspection apparatus is provided. The non-destructive inspection apparatus according to any one of claims 2 to 5, wherein the moving means is equipped with an imaging means for imaging the surface of the inspection object.

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