JPS61260159A - Tire type probe - Google Patents

Abstract

PURPOSE:To detect accurately flaws of a thin steel plate by providing a holding member with a supporting tire and a flaw detecting tire and supporting a load with the supporting tire and making the thickness of the flaw detecting tire thin and transmitting an ultrasonic wave from the inside of this tire to receive it. CONSTITUTION:A supporting tire 2 and a flaw detecting tire 17 are supported by a frame body 1. The supporting tire 2 consists of thick synthetic rubber or the like and is supported with a shaft 4 by the frame body 1 and a disc 6. The flaw detecting tire 17 is supported by the first shaft 9 and the second shaft 10, and the thickness of this tire is made thin, and a part 17a in the breadthwise direction is made thinner. A spindle 12 is allowed to pierce the second shaft 10, and a probe 20 is attached to the spindle 12 to transmit and receive the ultrasonic wave to and from the thin part 17a. A thin steel plate P is carried under both tires, and the load of a flaw detector is almost supported by the supporting tire 2, and flaws are detected by the flaw detecting tire 17. Since the flaw detecting tire is made thin and the ultrasonic wave having a high frequency is projected on the steel plate, flaws of the thin steel plate are grasped accurately continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tire-shaped probe for an ultrasonic flaw detector that detects defects in ultra-thin steel sheets using ultrasonic waves.

[Prior art]

An ultrasonic transmitter/receiver is provided inside a rubber tire, the inside of the tire is filled with water or oil, and a material to be inspected such as a steel plate being conveyed at high speed is brought into continuous contact with the outer peripheral surface of the tire. Tire-shaped probes for detecting defects present in inspected materials are known. In addition, by making it possible to change the installation angle of the ultrasonic transmitter/receiver attached to this type of tire-shaped probe and changing the incident angle of the ultrasonic waves to the material being inspected, flaw detection modes can be freely and continuously. It is also known that the inspection accuracy can be improved by changing the
No. 71).

By the way, there are various problems in continuously testing recently produced thin steel plates having a thickness of about 0.2 to 0.3 fins on a production line using conventional tire-shaped probes.

First, the flaw detection frequency of currently commercially available transmitter/receivers is 1 to 2 MB2 at most. FIG. 2 shows a graph of the modes when these thin steel plates are continuously tested for flaws on a production line. In this Figure 2, the vertical axis is the ultrasonic incident angle, and the horizontal axis is the frequency (MHz) and plate thickness (VA).
) is expressed as the product of

For example, if the thickness of the thin steel plate is 0.2 mm and the flaw detection frequency used at that time is I MHz, the product of both will be 0.2, and the value will be above the 0.2 position on the horizontal axis in Figure 2. , it intersects the curve indicating the So mode. When the incident angle at this time is read from the vertical axis, it is found to be approximately 16.3 degrees. However, in general, this 30 mode has a problem that the waveform is broad and the resolution is poor.

Secondly, the steel pieces such as slabs that are used as these materials are now mostly manufactured by continuous casting, and the defects that occur are becoming smaller. Therefore, when detecting minute defects, a common method is to increase the flaw detection frequency in order to improve the resolution. In addition, the tire rim of the tire-shaped probe is made of a flexible material such as rubber, and its thickness is 2 to 3 mm.
It is only a slight reduction. FIG. 3 shows the relationship between the thickness of the rubber film and the echo height; the thinner the film is, the higher the echo level can be obtained. As the frequency becomes higher, the attenuation in the rubber part becomes more significant.
If z is increased, the thickness of the rubber used for the tire rim will be approximately 0.2
It is necessary to make it extremely thin with ~0.3 fi. By the way, if the rubber used for the tire rim is made thinner to 0.2 to 0.3 mm, the tire rim will not rotate smoothly because it will come into continuous contact with the material to be inspected, such as a thin steel plate that moves at high speed. This is difficult and may lead to accidents such as tire rim wear and rupture.

Thirdly, in a tire-shaped probe, since the inside of the tire is filled with water or oil, it is necessary to tightly connect the sealing material to the shaft to prevent water or oil from leaking. The problem is that the rotational movement of the tire is hindered and the tire does not rotate smoothly, and making the thickness of the tire even thinner will further exacerbate this problem.

Fourth, when performing flaw detection, water or oil is dropped onto the thin steel plate in front of the tire-shaped probe as an ultrasonic propagation medium to form a water or oil film between the tire rim and the thin steel plate. If the rotation of the tire is not smooth, these water or oil films will act as a lubricant, causing problems such as poor rotation of the tire rim and uneven wear of the tire rim, leading to damage to the tire rim. . Therefore, thinning tires is dangerous.

〔the purpose〕

The present invention was made to solve these problems, and is a tire-shaped probe capable of detecting flaws in thin steel sheets transported at high speed using ultrasonic waves in a high frequency range. The purpose is to provide children.

(Structure) The tire-shaped probe according to the present invention includes a support tire and a flaw detection tire that are rotatably supported by a common holding member, and the thickness of the tire member of the flaw detection tire is reduced. , is formed of a tire member thinner than the support tire, and is characterized by having an ultrasonic transmitter/receiver on the inside of the flaw detection tire, which continuously detects defects existing in the IS plate, and is capable of This solves the problems of tire-shaped probes.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a sectional view of a tire-shaped probe according to the present invention.

This tire-shaped probe A is of a double-tire type, and has a support having a tire rim made of sufficiently thick synthetic rubber inside one side of the probe frame 1, which is formed in a U-shape in cross section. tires 2 are provided. This support tire 2
A supporting tire shaft 4 whose one end is rotatably supported by a bearing 3 provided on one side of the probe frame 1;
The inner circumferential edge 2a of the support tire 2 is attached to the tire mounting groove 58 formed on the outer circumferential surface of the tire wheel 5 that is integrally attached to the tire wheel 5.
It is installed by inserting it. The other end of the tire wheel 5 is provided with a threaded shaft portion 5b. The inside of the support tire 2 is pressurized and filled with air, and the support tire 2 contacts the steel plate P, which is the material to be inspected, so that the steel plate P
It is designed to perform smooth rotational movement by conveying the material.

The supporting tire 2 may be a solid tire in which the air-filled portion is also filled with rubber.

In addition, the screw of the screw shaft portion 5b is installed in the opposite direction to the rotation direction of the support tire 2 that rotates when the steel plate P is conveyed, so that the connection with the disk 6, which will be described later, does not come off when the steel plate P is conveyed. That's how it is. The threaded shaft portion 5b includes a connecting shaft portion 6a having a small-diameter cylindrical shape and having a threaded groove formed on its inner circumferential surface.
A large-diameter cylindrical bearing support portion 6b concentric with the connecting shaft portion 6a.
The connection shaft portions 6a of the disks 5 having the above-described connection shaft portions 6a are joined together to connect them.

A bearing support member 8 into which a bearing 7 is fitted is fixedly attached inside the bearing support portion 6b. One end of a first shaft 9 is rotatably supported by this bearing 7.
A second shaft 10 is attached to the other end of the first shaft 9. The second shaft 10 includes a gear accommodating portion 10a having a U-shaped cross section and a shaft cylindrical portion 10b connected thereto. One end is rotatably supported by a bearing 11 fitted inside an example of the gear accommodating part 10a, and the other end is inserted through the shaft cylinder part 10b and supported on the other side of the probe frame 1. A shaft rod 12 is provided.

A knob 13 is attached to the end of the shaft rod 12 extending from the other side of the probe frame 1, so that the shaft rod 12 can be rotated in a semi-fixed manner. A bearing support member 8' having the same size and shape as the bearing support member 8 is fixedly attached to the end side of the shaft cylindrical portion 10b of the shaft rod 12. A bearing 7' having the same shape is fitted. Also, oil seals 14 are provided on both sides where the bearings 7 and 7' face each other.
14' is provided. Further, a tire mounting member 15.15' is fixedly attached to the outer circumferential surface of the bearing support members 8, 8', and a holder 16.16' connected to the tire mounting member 15.15' is made of synthetic rubber. The flaw detection tire 17 is attached to a tire mounting member 15, 15' by sandwiching the inner peripheral edge of the flaw detection tire 17.

This flaw detection tire 17 has a thin thickness of approximately 0.2 to 0.3 N at approximately half the axial width portion 17a of the outer circumferential surface, and a thickness of 2 to 3 fl on the other outer circumferential surface to increase strength. It's sato. The inside of the flaw detection tire 17 is filled with a liquid such as water or oil, which is an ultrasonic medium.

The support tire 2 and the flaw detection tire 17 are rotatably supported by a common holding member consisting of a support tire shaft 4, a first shaft 9, and a shaft rod 12. It is designed to rotate smoothly in conjunction with the tires 17. The liquid filled in the flaw detection tire 17 is prevented from leaking by the oil seals 14 and 14'.

A worm gear 18 is attached to the shaft 12 on which the gear accommodating portion 10a of the second shaft 10 is located, and an ultrasonic transmitter/receiver 20 rotatably supported by a pin 19 is attached to the worm gear 18. The ends of the support plate 21 to which the holder is attached are engaged with each other. Therefore, loosen the knob 13 and
By rotating 2, the mounting angle of the ultrasonic transmitter/receiver 20 can be changed, and the angle of incidence of ultrasonic waves onto the steel plate P can be changed.

The tire-shaped probe according to the present invention configured as described above has the following features:
An elevating mechanism (not shown) positions the outer peripheral surfaces (tire surfaces) of the support tire 2 and the flaw detection tire 17 so as to contact the surface of the thin steel plate P, which is the material to be inspected. On the other hand, the orientation of the ultrasonic transmitter/receiver 20 is set so that the ultrasonic waves from the ultrasonic transmitter/receiver 20 pass through the thin wall portion of the flaw detection tire 17 at a required angle of incidence. After that, when the i steel plate P of the material to be inspected is transported,
The support tire 2 and the flaw detection tire 17 rotate and come into contact with the im plate P, and the ultrasonic beam oscillated by the ultrasonic transmitter/receiver 20 enters the thin steel plate P through the liquid and the flaw detection tire 17. When a flaw exists in the propagation path, a reflected wave from the flaw will be captured by the ultrasonic transmitter/receiver 20 and processed as a flaw signal.

For example, if the flaw detection frequency is set as high as 10 to 15 MIIz and the thickness of the thin steel plate P is 0.2N, the product of the flaw detection frequency and the thickness of the thin steel plate P will be 2 to 3, as shown in Figure 2. Ta2~
'1 following the position of 3 upwards + al l So
It is compatible with four types of modes: +ao. Generally a
Since the pulse width of the mode is narrower than that of the S mode, the resolution is higher. Therefore, it is possible to set the flaw detection frequency to a high frequency range and select a mode in which the flaw is passed through the thin steel plate P for inspection. This can be said to be an advantage of the present invention compared to the conventional method in which only 5Q mode was used. Also,
Since the support tire 2 is formed with a thick wall and is supported on the thin steel plate P, its rotation is performed smoothly, and the flaw detection tire 17 having a thin wall portion rotates together with the support tire 2. It is possible to prevent the flaw detection tire 17 from being worn out or bursting due to strong pressure and frictional force being applied to the flaw detection tire 1.
7 fully exhibits the flaw detection function and can withstand long-term use.

In addition, according to this embodiment, the support and flaw detection glue ear 2,
17 are all made of tire rims made of synthetic rubber, but it goes without saying that similar effects can be obtained even if they are made of other materials. Further, the liquid filled inside the flaw detection tire 17 is not limited to water or oil. Further, the thickness of the flaw detection tire 17 may be a constant thickness of 0.2 to 0.3 mm over its entire width.

〔effect〕

As described in detail above, the tire-shaped probe A according to the present invention rotatably supports the support tire 2 and the flaw detection tire 17 on a common holding member, and the flaw detection tire 17 is formed of a thin wall. Since the ultrasonic transmitter/receiver 20 is provided inside,
By increasing the frequency of the ultrasonic transducer 20 and projecting it onto the thin steel plate P, flaws in the thin steel plate P can be accurately detected. In addition, since most of the load of the probe A or the reaction force from the steel plate P is supported by the support tire 2, large pressure is not applied to the flaw detection tire 17, which has a thin wall portion, and wear and tear due to rolling contact can be prevented. , and the flaw detection function can be fully demonstrated due to smooth rotation. Therefore, according to the present invention, the thin steel plate P
This makes it possible to conduct high-precision flaw detection and inspection, and it will greatly contribute to industry by solving the problems of the past.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and Fig. 1 is a cross-sectional view of a tire-shaped probe according to the present invention, and Fig. 2 is a cross-sectional view of the product of frequency and plate thickness and angle of incidence for flaw detection. Graph showing the relationship. FIG. 3 is a graph showing the relationship between the height of the reflected echo and the thickness of the rubber film of the tire when a steel plate is vertically inspected. 1... Probe frame 2... Supporting tire 4... Supporting tire shaft 5... Tire wheel 9... First
Shaft 10... Second shaft 12... Axis rod 15.15'... Tire mounting member 17... Tire for flaw detection 20... Ultrasonic transducer/receiver L... When liquid
Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent Attorney
Noboru Kono □□□□−=− ! j1#xgc4 (MH!/5ecX””) Joy 2
For concave combs (thickness 3v; J

Claims (1)

[Claims] 1. A support tire and a flaw detection tire are rotatably supported by a common holding member, and the flaw detection tire is formed of a thinner tire member than the support tire, and has an ultrasonic transducer/receiver element inside thereof. A tire-shaped probe characterized by being provided with.