JPH0375824B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves making an ultrasonic probe revolve around a test specimen on a flat plate at a constant rotation radius and moving it in translation relative to the specimen. The present invention relates to a probe scanning device that scans a sonic probe on a plane of a test object.

[Prior Art] Conventionally, as a scanning device for an ultrasonic probe in an ultrasonic flaw detection device, there are devices as shown in FIGS. 2 to 4.

In the device shown in FIG. 2, a scanning carriage 4 is mounted on a frame 2 that straddles a strip-shaped specimen S in the width direction, so as to be able to reciprocate in the width direction of the specimen S. It is constructed by arranging (three in the figure) ultrasonic probes 6 in a line along the longitudinal direction of the test piece. This device moves the specimen S in the longitudinal direction (in the direction indicated by the arrow A in the figure), and also moves the ultrasound probe 6 in the width direction of the specimen S by reciprocating it on a frame 2 using a scanning cart 4. By reciprocating, a sinusoidal scanning locus is obtained.

The one shown in FIG. 3 is suitable for a wide test specimen S, and a plurality of scanning carts 4 each carrying one ultrasonic probe 6 are mounted on a frame 2 at appropriate intervals. It is arranged and configured. This moves the frame 2 in the direction of arrow A to obtain a number of parallel sinusoidal scanning trajectories.

These devices can narrow the scanning pitch by increasing the number of ultrasonic probes 6 arranged (example in Figure 2), or reduce the reciprocating amplitude of the scanning carriages 4 by increasing the number of scanning carriages 4. , and efforts are being made to improve the round-trip frequency.

On the other hand, as shown in Figures 4 and 5, a combination of so-called scanning (SCAN), which performs flaw detection by traveling at high speed, and so-called stepping (INDEX), which moves a certain amount in a direction perpendicular to the scanning, is used. There is a scanning method that performs vertical rectangular scanning or horizontal rectangular scanning. This scanning method is particularly useful in water immersion flaw detection, in which the test material is placed in a water tank and ultrasonic flaw detection is performed.
This is commonly done.

Further, as shown in FIG. 6, a plurality of rotary drive devices 8 are arranged on the frame 2, and each rotary drive device 8
An ultrasonic probe 6 is attached to the frame 2, and while the ultrasonic probe 6 is revolved at a constant radius, the frame 2 is attached to the test body S.
There is one that forms a scanning locus in the shape of a cycloid curve by relatively moving it along the longitudinal direction.

[Problems to be solved by the invention] However, these conventional scanning devices have the following problems:
Each has the following drawbacks.

That is, the devices shown in FIGS. 4 and 5 have the disadvantage that high-speed flaw detection is difficult.

The reason is that, first, the probe and its holding part, including its mounting tool and attached manipulator,
It has a certain weight, especially when it has a certain spread of arrangement in a multi-channel configuration, it becomes quite heavy, and in order to make it reciprocate at high speed, a considerable amount of energy is required for acceleration and deceleration. As the drive device becomes larger, there is a certain limit to the scanning speed, and a considerable distance is required for acceleration and deceleration, forcing a reduction in the reciprocating frequency.

The second reason is that as the speed of reciprocating motion increases, it becomes difficult to control the speed of deceleration, stop, and acceleration.
The shock caused by rapid acceleration and deceleration not only causes significant damage to the holding mechanism, but also disturbs the orientation of the ultrasonic probe and disrupts the movement of the probe material (water) necessary for ultrasonic flaw detection. This may occur and have a negative impact on flaw detection.

On the other hand, in the case of circular scanning shown in FIG. 6 above,
There are no such problems. On the contrary, since circular scanning is based on rotational motion, it has the advantage of being able to obtain a much higher reciprocating frequency than in the case of reciprocating motion by designing with consideration to rotational balance and the like. Further, in circular scanning, the acceleration applied to the probe portion is constant, and there is little occurrence of flaw detection noise echoes due to disturbances in the couplant. In addition, there is an advantage that special mechanisms such as "stroke setting" and "acceleration/deceleration control", control circuits, sensors, etc. required for reciprocating scanning mechanisms are not required.

However, conventional circular scanning has the following drawbacks.

First, since it is necessary to use a signal transmission device such as a slip ring or a rotary transformer, it cannot be easily introduced into flaw detection at hand, and there is a risk of generating noise.

Second, the orientation of the probe mounted on the rotating part is
Since it changes moment by moment as a result of rotational scanning, it has the disadvantage that it cannot be applied to ultrasonic flaw detection based on detection methods with directional characteristics, such as flaw detection using split probes and oblique angle flaw detection.

The present invention has been made to solve the above-mentioned drawbacks, and its first purpose is to perform rotational scanning while keeping the orientation of the probe mounted on the rotating part constant on the revolution plane. To provide a probe scanning device for an isothermal wave flaw detection device, which can easily perform high-speed flaw detection without requiring a signal transmission device to a rotating part, and generates little noise.

In addition, the second object of the present invention is to introduce ultrasonic flaw detection, which has many advantages as described above, into directional ultrasonic flaw detection such as flaw detection using a split probe and oblique angle flaw detection. An object of the present invention is to provide a probe scanning device.

[Means for Solving the Problems] A probe scanning device of an ultrasonic flaw detection device for achieving the above object includes a frame, a mounting body for mounting a probe, and a connection between the frame and the mounting body. and a plurality of links, so that the plurality of links can move while maintaining a parallel state to each other,
Each link is rotatable about one end of the frame on a plane parallel to the revolution plane, and one end of each link is attached to the frame via a rotating shaft, and the mounting body , each link can freely rotate around its other end on a plane parallel to the revolution plane,
The other end of each is attached to the above-mentioned attachment body via a rotating shaft.

[Function] By the way, when an ultrasonic probe is fixed to the tip of a rotating arm and the arm is rotated about its base end as the center of rotation, the ultrasonic probe will revolve around the center of rotation. Become. At the same time, when observed from a non-rotating inertial frame, the ultrasonic probe
It is the same as one rotation per revolution. Therefore,
Ultrasonic probes that perform this type of circular scanning cannot transmit signals using cables due to twisting, and require a signal transmission device such as a slip ring. Furthermore, since this ultrasonic probe rotates with respect to the above-mentioned inertial system, it is not possible to perform directional flaw detection.

In contrast, in the present invention, the ultrasonic probe is rotated in a direction opposite to the revolution at an angle equal to the revolution in the revolution system. As a result, the rotation of the direction of the probe due to revolution is canceled out, and the same attitude is maintained without rotating relative to the non-rotating inertial frame.

In other words, since the frame, each link, and the mounting base constitute a parallel link mechanism, the probes attached to the mounting base revolve while facing in the same direction.

Therefore, signal transmission can be performed using a cable, and signal transmission equipment such as a slip ring is not required. Furthermore, since the direction of the ultrasonic probe does not change, it is also possible to perform directional flaw detection.

[Example] An example of the present invention will be described with reference to the drawings.

FIG. 1A is a partially enlarged sectional view showing the configuration of an embodiment of the probe scanning device of the present invention, and FIG. 1B is an explanatory diagram showing the attachment relationship of links constituting the above embodiment.

The probe scanning device shown in the figure includes a frame 2,
It includes a mounting plate 110 to which the probe 28 is attached, and three links 88, 90, and 92 that connect the frame 2 and the mounting plate 110 in a relatively movable manner, and each link has one end attached to the frame 2. The other end is rotatably attached to the mounting plate 110 so that each link can rotate while maintaining a parallel relationship with each other.

The links 88, 90, and 92 are formed to have the same length, and each has a rotating shaft 82, 84, and 86 attached to one end thereof, and a rotating shaft 11 attached to the other end.
6, 118 and 120 are attached, the former connecting with the frame 2 and the latter connecting the mounting plate 1.
10 is attached. Axis of rotation 82, 84 and 86 at one end of each link 88, 90 and 92
The distance between the rotation shafts 116, 118, and 120 at the other end is D/2, where D is the revolution diameter of the ultrasonic probe 28.

Among the rotating shafts 82, 84 and 86, the rotating shaft 8
2 is fixed to a link 88, and rotating shafts 84 and 86 are rotatably connected to links 90 and 92. For example, the rotating shaft 84 may include a bearing 94.
It is rotatably connected to the bearing 104 via.

Rotating shafts 116, 118 and 120 are rotatably coupled to links 88, 90 and 92.
For example, when rotating 116, 118, the bearing 9
It is rotatably connected to corresponding bearings 100 and 102 via bearings 6 and 98.

The frame 2 is provided with bearings for rotatably connecting and supporting the rotating shafts 82, 84, and 86. In FIG. 1A, bearings 74, 78 for rotating shafts 82 and 84 are shown. Both rotatably support corresponding rotating shafts 82 and 84 via bearings 76 and 80, respectively. Note that a driving electric motor 200 is connected to the rotating shaft 82.

The mounting plate 110 rotatably connects the rotating shafts 116, 118, and 120, and is swingably supported by these. For example, rotating shafts 116 and 118 are coupled to bearings 112 and 114 via bearings 106 and 108. Also,
An ultrasonic probe 28 is attached to the lower surface side of the mounting plate 110.

The operation of the above embodiment will be explained with reference to FIGS. 1A and 1B.

In the above embodiment, when rotating 82, the electric motor 20
0, for example, when rotated counterclockwise,
A link 88 to which the rotating shaft 82 is fixed rotates around the rotating shaft 82. this link 88
As the link 88 rotates, the rotating shaft 116 connected to the link 88 rotates and moves the mounting plate 110.

Along with this movement of mounting plate 110, other links 90 and 92 also rotate via rotating shafts 118 and 120, respectively. Link 88,90
and 92 are in a parallel link relationship with each other, so their rotation direction, phase, and angular velocity are equal to those of the link 88. The rotational trajectories of these links 88, 90 and 92 are shown in FIG. 1B as Cf, Cg and Ch.

As the links 88, 90, and 92 rotate, the mounting plate 110 swings so that its center draws a circle. Rotating shafts 116, 118 of mounting plate 110
and 120 are on the same circumference, and the mounting plate 11
The positions of maximum amplitude in the front, back, left and right of this circumference due to the motion of 0 are indicated by Ca, Cb, Cc and Cd in FIG. 1B.

Furthermore, since the ultrasonic probe 28 is attached to the center of the rotating shaft mounting plate 110, the mounting plate 11
The motion trajectory of the center of 0 becomes the orbital trajectory of the ultrasound probe 28. This trajectory is expressed as a small circle in Figure 1B.
Shown in Ce. In the circle Ce, Oa, Ob, Oc and Od are the rotation axes 116, 118 and 1
This is the center position of the mounting plate 110 corresponding to the maximum amplitude positions Ca, Cb, Cc, and Cd of the circumference connecting the points 20.

Now, the movement of the mounting plate 110 is vibration due to circular movement of its center, and it does not rotate itself. Therefore, the center position Oa of the mounting plate 110,
Ob, Oc, and Od all have the same orientation. Therefore, the ultrasonic probe 28 attached at this central position maintains its orientation constant and
It revolves around a small circle Ce.

Note that although the scanning device of this embodiment is equipped with only one probe per frame, if a scanning device equipped with a large number of probes per frame is used,
Deep scratches can be made at high density and at high speed on a wide specimen S. FIG. 1C is an example. That is, this is an example in which the scanning devices including the electric motor 200 and the probe 28 are arranged in a staggered manner.

[Effects of the Invention] As explained above, the present invention is capable of performing rotational scanning while keeping the orientation of the probe mounted on the rotating part constant on the rotating plane. This has the effect of realizing a probe scanning device for an ultrasonic flaw detection device that does not require any signal transmission equipment, can easily perform high-speed flaw detection, and generates little noise.

Furthermore, the present invention provides an ultrasonic flaw detection device that can introduce circular scanning, which has many advantages as described above, for directional ultrasonic flaw detection such as flaw detection using a split probe and oblique flaw detection. This has the effect of realizing a child scanning device.

[Brief explanation of drawings]

FIG. 1A is a partially enlarged sectional view showing the configuration of an embodiment of the probe scanning device of the present invention, FIG.
Fig. C is a plan view showing an example in which the above embodiment is applied to a wide-width test specimen, Figs. 2 and 3 are plan views each showing a conventional scanning device, and Figs. 4 and 5 are plan views showing a conventional scanning method. FIG. 6 is a plan view showing a conventional rotary scanning device. 2...Frame, 4...Scanning trolley, 6,28...
...Ultrasonic probe, 8...Rotary drive device, 74,7
8,100,102,104...Bearing, 82,8
4, 86, 116, 118, 120... rotating shaft,
76, 80, 94, 96, 98, 106, 108
...Bearing, 88,90,92...Link,
200...Electric motor.

Claims (1)

[Scope of Claims] 1. An ultrasonic probe is caused to revolve around a test object on a flat plate at a constant radius of rotation, and is also moved in translation relative to the test object, so that the ultrasonic probe is placed on the plane of the test object. A probe scanning device for an ultrasonic flaw detection device that scans with In order to be able to move while maintaining a state parallel to each other, each link is rotatable about one end of the frame on a plane parallel to the revolution plane, and one end of each link connects to the frame via a rotation axis. At the same time, each link is rotatable about the other end of the mounting body on a plane parallel to the revolution plane, and the other end of each link is connected to the mounting body through the rotation axis. A probe scanning device for an ultrasonic flaw detection device, characterized in that it is attached to.