JPS6136930Y2 - - Google Patents

Description

[Detailed Description of the Invention] Ultrasonic flaw detectors generally measure the distance from a surface to a defect using the A-scope method. That is, the time axis is the horizontal axis of the cathode ray tube oscilloscope, and the transmitted pulse and the defective echo or bottom echo pulse are added to the vertical axis to measure the time from the point of emission of the transmitted ultrasonic wave to the echo pulse. In this case, the measurement range on the time axis is changed depending on the thickness of the sample and the like. Therefore, conventionally, for example, the dimension between the emission point of the transmitted ultrasonic wave and the rising point of the defective echo was read using a scale provided on the screen of the cathode ray tube, and this value was combined with a coefficient indicating the measurement range on the time axis. I had to find the product. For this reason, it is not possible to directly read the position of the defect, and there are many erroneous observations due to calculation errors.
The present invention eliminates the above-mentioned drawbacks and provides an ultrasonic flaw detector that can directly read the location of defects in digital quantities.

The drawings show one embodiment of the present invention, and Figure 1 is a front view;
FIG. 2 is a partially sectional plan view, and FIG. 3 is a perspective view of the main parts. A screen for the cathode ray tube is disposed on the front surface of the casing 2 housing the cathode ray tube 1 in this manner, and a scale plate 3 is provided in front of the screen. A threaded rod 4, which is longer than the screen, is placed horizontally above the screen of the cathode ray tube 1 and is rotatably held therein, and a slider 5 is screwed onto this threaded rod. The slider 5 has one aiming line 6 perpendicular to a strip plate made of transparent acrylic resin, for example.
The indicator 7 provided with this is attached, and the indicator 7 protrudes from the groove 8 of the casing to the front of the casing, and is arranged in front of the scale plate 3. Note that the index 7 has different colored aiming lines 6 on both the front and back sides of the acrylic resin plate as necessary.
Parallax can be prevented by providing a superimposed image and observing it from the position where they overlap. Further, a drive ring 9 and a pinion gear 10 are attached to the threaded rod 4, so that a part of the ring 9 protrudes from the groove of the housing to the front thereof, and the gear 10
The drive gear 12 of the operation amount switching device 11 is meshed with the drive gear 12 of the operation amount switching device 11. The operation amount changer 11 changes the ratio of the amount of rotation between the drive gear 12 on the input side and the rotating shaft 13 on the output side by switching the gear transmission path.
The above switching is performed by a handle 15 that projects from the front of the housing. A mechanical digital counter 16 is connected to the output side rotating shaft 13 of this operation amount switching device 11, and the reset button 1 of the counter 16
7 and a display section 18 protrude from the front of the housing.

In the device described above, the threaded rod 4 and the drive ring 9
The slider 5 and the like constitute a drive mechanism for the movable indicator 7, and when the ring 9 is rotated with a fingertip, the indicator 7 moves in the horizontal direction, that is, in the horizontal axis direction of the cathode ray tube 1. The horizontal axis of the cathode ray tube 1 has a sawtooth wave input on the time axis, and the vertical axis shows the ultrasonic transmission pulses, defective echo pulses, and bottom echoes emitted into the sample from the vertical or oblique probe. Pulses etc. are applied. Therefore, when using a vertical probe,
As shown in FIG. 3, waveforms such as the above-mentioned transmission pulse a, defective echo pulse b, and bottom echo pulse c appear on the screen of the cathode ray tube. In order to find the position of the defect in this waveform, the handle 15 of the operation amount switch 11 is set to an appropriate position according to the inclination angle of the sawtooth wave, that is, the set value of the measurement range on the time axis. Next, move the index 7 to align the aiming line 6 with the ultrasonic pulse emission reference time and press the reset button 1.
7 to set the value on the display section 18 to "0000", and then move the index 7 again to match the rising point of the defect echo b. In this state, the position of the defect can be directly read from the numerical value appearing on the display section 18.

As explained above, the ultrasonic flaw detector of the present invention can directly read the position of a defect as a digital quantity by simple operation. In addition, it has excellent effects such as being simple in structure, small in size, and inexpensive to manufacture.

[Brief explanation of drawings]

Fig. 1 is a front view of the embodiment of the present invention, and Fig. 2 is a front view of the embodiment of the present invention.
A cross-sectional plan view of a part of the device shown in the figure, Figure 3 is the first
FIG. 3 is a perspective view of the main parts of the apparatus shown in FIGS. In the figure, 1 is a cathode ray tube, 2 is a housing,
3 is a scale plate, 4 is a threaded rod, 5 is a slider, 6 is a target line, 7 is an index, 9 is a drive ring, 11 is a movement amount switch, and 16 is a digital counter.

Claims (1)

[Scope of utility model registration request] A drive mechanism in which a movable index indicating a position on the horizontal axis is arranged on the front surface of a cathode ray tube to which the horizontal axis is the time axis and a transmission pulse and a defective echo pulse are applied to the vertical axis, and the movable index is moved in the direction of the horizontal axis. , and the drive mechanism is connected to a digital counter via a motion amount switching device that can convert the ratio of the motion amount on the input side to the motion amount on the output side in accordance with switching of the measurement range of the time axis. Sonic flaw detector.