JPS581361B2 - Ultrasonic dimension measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the measurement accuracy of an ultrasonic dimension measuring device.

In recent years, automatic measurement of the inner and outer diameters and wall thicknesses of various pipes over their entire length has become convenient by using ultrasonic dimension measuring devices.

The ultrasonic dimension measuring device is configured as follows, for example.

That is, as shown in FIGS. 1 and 2, there are tubes to be measured (hereinafter referred to as
Inlet 2 for feeding and discharging pipe (simply referred to as "pipe 1")
2a and an exit 22b are provided, and these entrances and exits 22a,
22b is sealed by suitable sealing mechanisms 23a, 23b which can substantially prevent leakage of water without interfering with the movement of the tube 1.

The tube 1 is rotated around the axis by spiral feed rollers 24 provided at the front and rear of the tank 20 and fed in the direction of the stop.

The tank 20 has a measurement member 29 consisting of measurement ultrasonic probes (hereinafter referred to as measurement probes) 27a and 27b on both sides of the movement path of the tube 1, and a slug 28a and an ultrasonic wave for water temperature compensation on both sides above the measurement member 29. The compensating member 30 includes a probe (hereinafter referred to as a compensating probe) 28b and the like.

When the ultrasonic waves emitted by the measurement probes 27a and 27b are perpendicularly incident on the surface of the tube 1, surface echoes 81 and S2
and bottom echo Bll, B12, B13... and B2
19B22, B23... are generated.

The surface echoes S1 and S2 are generated when the incident wave is reflected on the surface of the tube 1, and the bottom echoes Bll, B12, Bt
a... and B21, B22, B23...S are tube 1
The wave is generated when an incident wave enters the inside of the tube 1 and is reflected by the inner circumferential surface of the tube 1.

The distance W1 between the probe 27a and the tube 1 is determined by the time interval between the oscillation pulse 01 on the measurement probe 27a side and the surface echo 81, and the distance W1 between the probe 27a and the tube 1 is determined by
The wall thickness T1 on this side of the tube 1 is determined by the time interval between the bottom echo B12 and the bottom echo B12.

Similarly, from the measurement probe 27b side, probe 2
Distance W2 between 7b and tube 1 and wall thickness T2 on this side of tube 1
is found.

If the constant corresponding to the probe spacing is C, then the outer diameter of the tube 1 is O
D1 wall thickness WT and inner diameter ID are respectively obtained as follows.

It goes without saying that the constant C is automatically corrected by the water temperature compensating probe 28b so that it remains constant even if the water temperature in the water tank changes.

However, conventional water temperature compensation alone is insufficient to measure the dimensions of tubes that require extremely strict dimensional accuracy, such as nuclear fuel cladding tubes.

That is, as shown in FIG. 1, there is a non-negligible difference between the water temperature near the water temperature compensation probe 28b (marked with *) and the water temperature near the measurement probes 27a and 27b (marked with **). In particular, when a hot-rolled tube passes through, this difference in water temperature becomes remarkable, and the temperatures of the measurement probes 27a, 27b and the compensation probe 28b must also differ from each other. Measurement probe 27a. 27b and compensation probe 28b
There will inevitably be a difference in the underwater sound speed of the ultrasonic waves emitted from the

However, the conventional ultrasonic measurement device has a measurement probe 27.
Since compensation and calculation were performed on the premise that the water temperature near a and 27b (points marked with **) and the water temperature near compensation probe 28b (points marked with *) were equal, measurements using this method , a non-negligible dimensional error was inevitable.

Further, although the compensating probe 28b compensates for dimensional errors due to changes in water temperature, momentary changes in water temperature are not a desirable phenomenon because they cause measurement errors.

Furthermore, stirring the entire water in the water tank 20 to equalize the water temperature is not only inefficient, but also generates bubbles that impede ultrasonic dimension measurement.

The present invention aims to eliminate the drawbacks of the conventional devices as described above.

That is, the present invention uniformizes the water temperature around both probes by efficiently moving water from the vicinity of the compensation probe to the vicinity of the measurement probe or vice versa in a short time,
Furthermore, by controlling the water temperature itself to be constant, the accuracy of dimensional measurement is improved.

The present invention will be explained below based on drawings showing embodiments thereof.

In FIGS. 3 and 4, the front and rear walls 61 of the surrounding member 6, which has an arbitrary shape such as a rectangular parallelepiped shape, are installed approximately in the middle of the water tank 5,
Openings 6a and 6b for the passage of the tube 1 are bored in the opening 62.

On the other hand, on the left and right side walls 63 and 64, a measurement member 2 consisting of measurement probes 27a and 27b is placed at the same height as the tube 1.
A compensation member 30 consisting of a compensation probe 28b, a reflector 288, etc. is attached to the upper position of 9, and the transmission/reception parts 271, 272, 28 of both members 29, 30
1 and the reflecting portion 282 are made to protrude into the interior of the surrounding member 6 within a range that does not contact the tube 1.

The lower part of the surrounding member 6 is provided with through holes 5c and 5d for water delivery.

9 is a base for fixing the surrounding member 6.

The tip of the pipe 6 is opened in the ceiling wall 65 of the surrounding member 6,
The rear end of the pipe 7 is connected to a pump 8 installed at the bottom of the water tank 5.
It is connected to the.

Further, a temperature sensor 10 such as a resistance thermometer is attached to the ceiling wall 65 of the surrounding member 6, with its detection portion 10a located inside the surrounding member 6.

An auxiliary water tank 11 is provided around the water tank 5, and a sealing mechanism 2
A spray nozzle 12 is installed around the pipe conduit in the auxiliary water tank 11 to blow off water that has leaked out from the pipes 3a and 23b by adhering to the surface of the pipe 1.

14 is a large tank, and a pipe 1 is connected to the auxiliary water tank 11.
They are connected by 3.

Further, the large tank 14 and the water tank 5 are communicated with each other by a pipe 15, and the pipe 15 contains water contained in the water supplied by a high-pressure pump 16 for sending the water in the large tank 14 into the water tank 5. A filter 17 for removing dust, etc., a cooler 18 for cooling the supplied water, a heater 19 for heating the supplied water, valves 20, 20, etc. are installed, respectively.

Note that the outlet 15a of the pipe 15 is arranged at a high position inside the water tank 5, and these pipes 13, tank 14, pipe 15, pump 16, filter 17, cooler 18, heater 19, valve 20, etc. Configure the device 24.

21 is a temperature setting device that sets a target temperature and outputs it as an electric signal a.

23 is a water temperature display meter that displays the output signal b from the temperature sensor 10, and 22 is a water temperature display meter that displays the two types of signals aq
This is a temperature control circuit that inputs signal b and controls the heating state of the heater 23 so that the difference between the values of both signals becomes zero.

The ultrasonic dimension measuring device of the present invention constructed as described above operates as described below.

The water in the water tank 5 sucked by the bomb 8 is transferred to the pipe 7
It flows into the interior of the surrounding member 6 from the ceiling wall 65 through the ceiling wall 65 and moves downward without being dispersed.

That is, it passes around the transmitting/receiving section 281 of the compensation probe 28b and the reflecting section 282 of the reflector 28a, and is immediately transferred to the measuring probe 27a. It reaches around the transmitting/receiving parts 271, 272 of 27b, and flows out from the lower through holes 6c, 6d of the surrounding member 6.

Therefore, the signal is transmitted from the compensation probe 28b, and the reflector 28a
It is possible to equalize the water temperature at the location where the ultrasonic wave reflected by the tube 1 passes and the water temperature at the location where the ultrasonic wave transmitted from the measurement probes 27a and 27b and reflected at the tube 1 passes.

In addition, since the pump 8 is installed at the bottom of the water tank 5, water that does not contain bubbles is sent into the surrounding member 6.
Bubbles, which are a major hindrance in ultrasonic dimension measurement, can be eliminated as much as possible.

On the other hand, water leaking from the sealing mechanisms 23a and 23b is stored in a tank 14 through an auxiliary water tank 11 and a pipe 13.

The water in the tank 14 is pumped into the pipe 1 by a high pressure pump 16.
5 into the aquarium 5, but in the process,
After dust is removed by a filter 17 and cooled by a cooler 18, it is heated by a heater 19.
The heater 19 is connected to a temperature control circuit 22 so that the water temperature in the surrounding member 6 matches the temperature set by the temperature setting device 21.
The water temperature inside the surrounding member 6 is maintained at the set temperature.

In the illustrated embodiment, the cooling state of the cooler 18 is not automatically controlled, but it goes without saying that the temperature control circuit 22 can perform the same control as the heater 19.

In short, temperature control can be performed on coolers and/or heaters.

Also, the outlet of the pipe 15 is at a shallow position (high position) in the water tank 5.
Since the water tank is opened upward, bubbles that inevitably occur while water circulates through the circulation device 24 do not enter the pump 8 and pipe 7 located at the bottom of the water tank 5.

It goes without saying that in the above configuration, a receiving probe may be provided in place of the reflector as the compensation member.

In each of the above drawings, each arrow indicates the flow of water.

When using the ultrasonic dimension measuring device of the present invention having the above-mentioned configuration, the variation in the indicated dimension values of a tube with an outer diameter of 12.5 φmm can be reduced to 0. We were able to keep the OO to 1 mm or less, and compared to the conventional ultrasonic dimension measuring device, which had a variation of about 0.01 mm, we were able to improve the measurement accuracy by about 10 times.

As described above, the ultrasonic dimension measuring device according to the present invention efficiently removes the measuring ultrasonic probe from around the compensation ultrasonic probe and the reflector without dispersing the water sent into it by the action of the surrounding member. Since the sonic probe is quickly moved to the vicinity of the sonic probe and the water temperature is made uniform, the compensation function can be performed accurately, and furthermore, it has the advantage of being able to prevent the generation of bubbles, which are fatal in ultrasonic dimension measurement.

Furthermore, if a pump for pumping water into the surrounding member is installed at the bottom of the tank, it is possible to prevent bubbles from entering the surrounding member.

Furthermore, if the water temperature is maintained constant using a temperature sensor, circulation device, etc., the accuracy of dimensional measurement can be further improved.

Furthermore, if the outlet of the pipe for feeding water into the water tank by the circulation device is installed at a high position within the water tank, it is possible to prevent bubbles from being sent into the vicinity of the measurement member within the surrounding member.

[Brief explanation of drawings]

Fig. 1 is a front sectional view showing a conventional ultrasonic dimension measuring device during pipe dimension measurement and the pulse waveform obtained from it, Fig. 2 is a side sectional view of the same device, and Fig. 3 is a book showing a conventional ultrasonic dimension measuring device during pipe dimension measurement. FIG. 4 is a side sectional view of the ultrasonic dimension measuring device according to the invention, and FIG. 4 is a partial front sectional view of the same device. 1...Pipe to be measured, 5...Water tank, 6...
... Surrounding member, 7 ... Pipe, 8 ...
...Pump, 10...Temperature sensor, 11.
...Auxiliary water tank, 13...Pipe, 14.
・・・；・・・Tank, 15・・・・・・Pipe, 16...
...High pressure pump, 17...Filter, 18
...Cooler, 19... Heater, 21.
... Temperature setting device, 22 ... Temperature control circuit, 24 ... Circulation device.

Claims (1)

[Scope of Claims] 1. A device for measuring dimensions such as the wall thickness of a pipe in an aquarium using ultrasonic waves, which includes a measuring member such as a measuring probe fixed at an appropriate position in the aquarium, and a compensating probe. Consisting of a compensating member such as a tentacle, a surrounding member that surrounds at least an ultrasonic transmitting/receiving section among the measuring member and the compensating member, and a pump for moving water within the surrounding member. An ultrasonic dimension measuring device featuring: 2. In a device that uses ultrasonic waves to measure dimensions such as the wall thickness of a pipe in a water tank, measuring members such as a measurement probe fixed at an appropriate position in the water tank and compensation probes, etc. A surrounding member that surrounds at least an ultrasonic transmitting/receiving section among the measuring member and the compensation member, a pump for exchanging water in the surrounding member, and detecting the water temperature in the surrounding member. a temperature sensor, a temperature setting device that sets a target temperature and outputs it as an electrical signal, and a temperature that outputs a signal that makes both agree based on the output signal from the temperature setting device and the signal from the temperature sensor. An ultrasonic dimension measuring device comprising a control circuit and a heater or cooler that heats or cools water in a water tank based on an output signal from the temperature control circuit. 3. The pump is installed near the bottom wall of the water tank, and supplies the water near the bottom wall to the inside of the surrounding member through a pipe. It is characterized by being equipped with a circulation device consisting of a pump, pipes, etc. for feeding water to a middle or high position inside the tank, and the circulating water is heated or cooled outside the tank by the heating or cooling device. An ultrasonic dimension measuring device according to claim 2.