JPH02105053A - Eddy current flaw detecting method for aluminum extruded member - Google Patents

Abstract

PURPOSE:To smoothly and quickly execute a flaw inspection work by always leading an extruding member being free from deformation into a flaw detecting coil by guiding automatically an Al extruded member extruded from a die to a guide sleeve, and straightening such deformations as bend, waviness, etc., in the process of passing through its tapered inner surface. CONSTITUTION:At the time of constituting a regular continuous eddy current flaw detector of a container 1, an andrel 2, a die 3, a flaw detecting coil 5, a graphite plate guide 6, a platen 7, a lifting jig 8, and a guiding graphite material 9, a guide sleeve 11 made of a graphite material is installed between the die 3 and the graphite plate guide 6 instead of a guiding graphite plate which is provided usually. In this case, the sleeve 11 is formed by combining a graphite member 12 whose upper face shows a tapered and inclined shape extending from an outlet side of the die 3 to an inlet side of the flaw detecting coil 5, and plane graphite members 13, 14 for constituting the side face and the bottom face, and the outer periphery is protected by an Al hollow material. In such a manner, bend of an extruded member which passes through the inside of the sleeve 11 is straightened automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an eddy current flaw detection method for continuously inspecting aluminum extruded sections for defects.

[Conventional technology]

In recent years, the use of aluminum for heat exchangers, especially heat exchanger materials for automobiles, has progressed, and quality requirements for aluminum materials have become stricter. For this reason, for aluminum extruded shapes, alloy discrimination inspection at the billet stage, defect inspection during extrusion,
A variety of quality control inspections are carried out, including eddy current flaw detection, microstructure inspection, and dimensional inspection for product inspection.

Among these, defect inspection during extrusion uses a through-coil type eddy current testing method to detect slight changes in shape that may cause gas leaks during the use process. It is carried out using

In Figure 6, ■ is a container, 2 is an andrel, and 3 is a container.
4 is an extrusion die, 4 is an extruded aluminum profile, and 5 is a flaw detection coil equipped with graphite plate guides 6 at the front and rear positions. The flaw detection coil 5 is installed on the top of a lifting jig 8 installed on the platen 7 together with a guiding graphite plate 9.

During operation, the flaw detection coil 5 is moved up and down by the lifting jig 8.
The billet 10 in the container 1 is extruded by properly positioning the billet 10 in the container 1. While sliding the extruded shape 4 on the upper surface of the guiding graphite material 9, the graphite plate guide 6
A method is adopted in which the microdefect is guided and inserted into the flaw detection coil 5, and a microdefect detection test is performed by changing the impedance of the coil due to a change in overcurrent, and then the next step is performed.

In the above configuration, there is also a multi-hole extrusion method in which a plurality of aluminum extruded sections 4 are extruded at the same time, and in this case, a device equipped with a plurality of holes corresponding to the die 3 and the flaw detection coil 5 is used. There is.

[Problems to be Solved by the Invention] However, in the conventional eddy current flaw detection method described above, when bends or waviness occur in the extruded aluminum profile extruded from the die, flaw detection is performed in that form without being corrected. Since it is introduced into the coil, damage to the flaw detection coil section often occurs.

Further, when using the multi-hole extrusion method, there are problems such as the shapes extruded from the die coming into contact with each other on the guiding graphite plate, causing scratches.

The present invention has been made to solve the above problems, and its purpose is to create an extruded aluminum profile that allows the profile extruded from a die to be introduced into a flaw detection coil in a straightened and separated state at all times. It provides an eddy current flaw detection method.

[Means to solve the problem]

That is, in the eddy current flaw detection method for extruded aluminum sections according to the present invention, an extruded aluminum section extruded from a die is introduced into a flaw detection coil and continuously inspected for defects. The gist of the structure is to introduce an extruded aluminum member into a flaw detection coil through a guide sleeve having a through hole that tapers off.

In the above configuration, the tapered shape refers to a shape in which the through hole of the guide sleeve exhibits a continuous tapered inner surface over the entire length or a part thereof, and in the case of a multi-hole extrusion method, the through hole in the guide sleeve has a shape that matches the position and number of die holes. A uniform guide sleeve with a hole formed therein is used, or a combination of guide sleeves with a single through hole of the above type is used.

Further, the guide sleeve must be made of a material with excellent surface smoothness and heat resistance, and graphite material is most suitable for this purpose.

[Effect]

According to the method of the present invention, the extruded aluminum profile extruded from the die is automatically guided to the guide sleeve, and deformed states such as bending and waviness are skillfully corrected in the process of passing through the tapered inner surface of the guide sleeve.

Therefore, an extruded aluminum profile without deformation is always introduced into the flaw detection coil.

Furthermore, when using the multi-hole extrusion method, the aluminum extruded shapes extruded from the die are introduced separately into separate through holes, so that the phenomenon of mutual contact is completely prevented.

[Example〕 Hereinafter, the present invention will be explained in detail based on examples.

Example 1 Continuous eddy current flaw detection device (numerals 1 to 9) with conventional structure shown in Fig. 1
(same as in Figure 6), in place of the guide graphite plate,
A guide sleeve 11 made of graphite material was installed between the die 3 and the graphite plate guide 6.

As shown in the side sectional view in FIG. 2 and the front view in the extrusion direction in FIG. It is formed by combining planar graphite members 13 and 14 that constitute the side and bottom surfaces, and the outer peripheral portion is fixed by an aluminum hollow member 15.

When an eddy current flaw detection test was performed on an extruded aluminum profile using the above-mentioned device, the extruded aluminum profile 4 extruded from the die 3 was automatically guided to the guide sleeve 11, and bent in the process of passing through the inner surface of the guide sleeve 11. It was introduced into the flaw detection coil 5 in a state in which deformations such as waviness were corrected. Therefore, the flaw detection coil 5 was not damaged at all.

Example 2 As the guide sleeve 11, a porous type having four through holes as shown in the side sectional view in FIG. 4 and the front view in the extrusion direction in FIG. 5 was used. The porous configuration in this case is a combination of the guide sleeves used in Example 1 with the lower two guide sleeves having their tapered surfaces reversed.

When this device was used to perform eddy current flaw detection on an extruded aluminum profile using the multi-hole extrusion method, the extruded aluminum profile 4 extruded from the die 3 was guided into each through hole of the guide sleeve 11 and separated. During this process, deformations such as bends and waviness were smoothly corrected. Therefore, the four aluminum extruded sections were introduced into the flaw detection coil 5 in a straightened state without contacting each other.

〔Effect of the invention〕

As described above, by using the present invention, proper continuous eddy current flaw detection can be performed at all times.

Therefore, smooth and quick defect inspection work on aluminum extruded sections is guaranteed.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side sectional view showing a continuous eddy current flaw detection device used in the method of the present invention. 2 is a side sectional view showing the guide sleeve shown in FIG. 1, and FIG. 3 is a front view of the guide sleeve shown in FIG. 2 in the extrusion direction. FIG. 4 is a side sectional view showing another embodiment of the guide sleeve, and FIG. 5 is a front view of the guide sleeve of FIG. 4 in the extrusion direction. FIG. 6 is a partially cutaway side sectional view showing a continuous eddy current flaw detection device used in the conventional method. 1... Container 2... Andrel 3...
Dice 4... Aluminum extrusion profile 5... Flaw detection coil 6... Graphite plate guide 7...
・Platen 8...Lifting jig 9...Guiding graphite material 10...Billet 11...Guide sleeve 12, 13.14...Graphite member 15...Aluminum hollow material Applicant: Sumitomo Light Metal Industries Tsukasa Kubo Patent Attorney Agent Co., Ltd. Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) In a method for continuous defect inspection by introducing an extruded aluminum profile extruded from a die into a flaw detection coil, the aluminum extrusion section is introduced into a flaw detection coil through a guide sleeve having a tapered through hole from the exit side of the die to the inlet side of the flaw detection coil. An eddy current flaw detection method for an extruded aluminum profile, which is characterized by introducing the extruded aluminum profile into a flaw detection coil. (2) The eddy current flaw detection method for aluminum extruded sections according to claim 1, wherein the guide sleeve is made of graphite material.