JPH0772053A - Full automatic machining method of charpy impact test piece - Google Patents

Abstract

PURPOSE:To prevent the formation of impression flaws and burr and to improve the accuracy of a notch machining part by providing dummy members for holding a test piece at both side-ends of a test piece in the cut-advancing direction, and thereafter forming cut grooves. CONSTITUTION:A test piece 1 is conveyed into a matching center, the surfaces A-D are machined so as to make fixing with jigs accurate, and deburring is performed at the angular parts of the machined parts. After the machined parts are fixed with fixing jigs 2, the material-taking part of the test piece 1 is machined. Furthermore, the scrap parts (parts used as dummy materials 6) at both ends of the test piece 1 are cut out. The finishing machining of the cut rough-surface parts is performed, and the test piece 1 is fixed 2 with two dummy materials 6 so as to hold the test piece 1 from both sides. In this state, a notch cutter 3 is used, and the grooves are cut in the order of the dummy material 6 - the test piece 1 - the dummy material 6, and the notch machining is performed to obtain the completed test piece 1. Impression flaws and burr, which are liable to occur at the edges on the input/output sides of the cutter 3 at the notch parts of the test piece 1, can be effectively prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fully automatic high-precision machining method for Charpy impact test pieces in which the rate of defective products is suppressed as much as possible.

[0002]

2. Description of the Related Art In recent years, high quality assurance of steel has become one of the important issues in steel production.
And, it is needless to say that such quality assurance can be achieved by a reliable manufacturing technique, but at the same time, a great role is played in a mechanical test for evaluating this. For this reason,
Recently, attention has been paid to the "Full-automatic mechanical testing system for steel materials" that can quickly and highly reliably evaluate it, which has spurred its development.

The Charpy impact test is no exception, and as a part of the development of a fully automatic mechanical test system, first, in order to improve the test accuracy, it is necessary to prepare a test piece conforming to the ASTM standard in which dimensional errors are stricter than JIS. In many cases, moreover, in this case, it is standardized that the processing state of the processed test piece (finished product) is strictly checked by a micrometer, each gauge and enlargement of the projector.

Here, in the measurement by the micrometer and each gauge, the dimensional error is about ± 20 μ, which is a very strict value in the conventional processing technique, but it is not enough due to the performance of the recent processing machines. It is a level that can be stably realized. The surface roughness is 6.3% even if it requires high precision.
Since it is about S, it is the same. The problem is the enlargement (about 50 times) check of the Charpy impact test piece by the projector. The portion to be enlarged and checked by the projector is mainly the V or U notch surface of the test piece.

Conventionally, the notch portion of the Charpy impact test piece is machined (notch processing) by fixing both end faces of the test piece 1 with fixing jigs 2 as shown in FIG.
The method of making a V or U-shaped notch groove was adopted. However, as shown in FIG. 3, in such a test piece, an indentation flaw 4 was formed at the end face of the cutter side, and a cutter was formed again.
Burrs 5 are generated on the exit side end face, and any of them is determined to be defective in the notched portion by the projector enlargement check.

For example, FIG. 4 is a projection enlarged photographic view (magnification: 38) of "V-notched portion of Charpy impact test piece which is V-notched by the method of FIG. 2" observed from the cutter entrance side.
Times). The unclear portion of the V-notched portion is an indentation flaw due to the cutter, and when such an indentation flaw that occurs on the cutter entry side is confirmed by the projector, the Charpy
The impact test piece is judged to have failed. In addition, FIG. 5 is a projection enlarged photographic view (magnification: 38 times) of "a V-notched portion of a Charpy impact test piece that has been V-notched by the method of FIG. 2" observed from the cutter exit side. The black discolored portion around the V notch shown in FIG. 5 is a burr generated during the cutting of the V notch. In this way, the cutter is used by the projector.
Even if the burr is confirmed on the exit side, the Charpy impact test piece is determined to be unacceptable.

As described above, the fully automatic Charpy
Notch processing of impact test pieces does not always satisfy the processing standard, so it was necessary to post-manufacture the manufactured test pieces to improve the test accuracy. It was one of the major obstacles in fully automating.

Therefore, an object of the present invention is to establish a fully automatic machining method for Charpy impact test pieces, which can stably perform particularly high precision notch processing and hardly cause defective products. Met.

[0009]

The present invention has been completed on the basis of the results of research conducted by the inventors of the present invention, which have been earnestly studied in order to achieve the above object. In the process, when cutting the groove into the test piece and processing the notch part, as shown in FIG. 1, attach the dummy material 6 for sandwiching the test piece 1 to the both ends of the test piece in the cutting progress direction, and then cut the groove. The feature is that the accuracy of the notched part can be dramatically improved by preventing the occurrence of indentation flaws on the end face of the cutter and the burrs on the end face of the cutter by inserting ``. It is a thing.

Needless to say, the above-mentioned notch processing can obtain good results even when processing one test piece, but a plurality of test pieces 1 are overlapped and the dummy material 6 is provided on both sides thereof. It is more efficient to carry out after sandwiching.

The present invention will be described in more detail below with reference to the drawings illustrating an example of the processing steps of a Charpy impact test piece. FIG. 6 is a conceptual diagram showing a material shape for manufacturing a plurality of Charpy impact test pieces as shown in FIG. 7 according to the method of the present invention.

When the material shown in FIG. 6 is carried to a machining center by a robot (manipulator), for example, as shown in FIG. A for correct fixing
The surface, the B surface, the C surface, and the D surface (see FIG. 6) are machined (the machined portion is shown by hatching in FIG. 8), and then deburring of the angular portion of the machined portion is performed. In the second step, the processing part in the first step is fixed to the jig, and then the central part of the material (test piece material removing part) is processed. Next, in the third step, the raw material is cut into five pieces, that is, a test piece portion (here, three pieces) and both end scrap portions (two pieces: a portion used as a dummy material in the fifth step). In the fourth step, finishing of the rough surface portion cut in the third step is performed. Then, in the fifth step, two dummy materials (scrap material in the third step) are used to fix the three test pieces side by side so that they are sandwiched from both sides, and in this state, the notch cutter is used. Three finished test pieces can be obtained by cutting the groove in the order of "dummy material → test piece → test piece → test piece → dummy material" and performing notch processing. The dummy material after this processing becomes a complete scrap material.

[0013]

[Operation and effect] As described above, when notch processing is performed by attaching the dummy material to both sides of the test piece in the notch processing direction, indentation flaws and cutters that are likely to occur on the cutter entry side of the notch part of the test piece. Since burr that tends to occur on the delivery side is effectively prevented, a large amount of highly accurate and proper Charpy impact test pieces can be stably manufactured.

For example, FIG. 9 is a projection enlarged photographic view (magnification: a V-notched portion of a Charpy impact test piece produced according to the method according to the present invention, observed from the cutter entry side.
38), and FIG. 10 is a projection enlarged photographic view (magnification: 3) of the V-notched portion of the same test piece observed from the cutter exit side.
8 times), but in each case, the notch surface is sharper than that of the conventional method (shown in FIGS. 4 and 5),
It can be seen that there is no indentation flaw or burr and the processing accuracy is high.

The scrap material (used as a dummy material) cut in the third step in FIG. 8 is advantageous in terms of automation cycle time if the subsequent deburring process is omitted. As shown in FIG. 11, the arrangement of the test piece and the dummy material during processing (fifth step in FIG. 8) is such that the end surface on the burr side of the dummy material 6 is on the outside. It is preferable that the test piece 1 can be smoothly inserted between the dummy materials 6 and 6 after setting the material 6 on the fixing jig without any trouble. Further, in order to more surely suppress the indentation flaw and the burr of the test piece, a level difference is provided on the notched surface between the damy material and the test piece as shown in FIG. 11, and the damy material is set higher. It is effective to perform notch processing.

If the method of manufacturing the test piece shown in FIG. 8 is adopted, the dummy material is inevitably the same as the material of the test piece, the cutting resistance becomes constant, and dent defects and burrs on the notch surface of the test piece are prevented. The effect is extremely remarkable. However, it is not always necessary to take the dummy material from the material at the same time, and it is also possible to prepare the dummy material from another material in advance. Even when a material different from the test piece is used as the dummy material, the effect of preventing indentation flaws and burrs on the notch surface of the test piece is reduced, but the occurrence of indentation flaws and burrs is smaller than in the conventional method.

By the way, as shown in FIG. 12, the processing equipment for carrying out the method of the present invention is composed of one machining center, one NC milling machine, and one robot (manipulator). However, another machining center may be installed instead of the NC milling machine. Also, if two machining centers, one NC milling machine, and one robot are used, the robot can be used more effectively, and the number of machining is 2.5 times in the calculation, and the equipment can be made highly productive. Of course, in any case, a fixing jig or a cutting tool may be appropriately used.

[0018]

[Summary of Effects] As described above, according to the present invention, it is possible to provide a fully automatic Charpy impact test piece machining method in which notch precision is dramatically improved. Improvement of test accuracy, that is, improvement of quality assurance can be achieved. (2) Mass production of high-precision Charpy test pieces by automatic processing (for example, if three test pieces make one set,
5 sets / day or more), (3) processing personnel can be reduced, (4) processing machine configuration can be made efficient, equipment costs can be reduced, etc. The effect is brought about.

[Brief description of drawings]

FIG. 1 is a conceptual diagram illustrating notching of a Charpy impact test piece according to the present invention.

FIG. 2 is a conceptual diagram illustrating notching of a conventional Charpy impact test piece.

FIG. 3 is a conceptual diagram illustrating a location where indentation flaws and burrs are generated by a conventional test piece notch processing method.

FIG. 4 is a projection enlarged photographic view (magnification: 38 times) of a V-notched portion of a Charpy impact test piece that has been V-notched by a conventional method, as observed from the cutter entry side.

FIG. 5 is a projection enlarged photographic view (magnification: 38 times) of a V-notched portion of a Charpy impact test piece that has been V-notched by a conventional method, as observed from the cutter exit side.

FIG. 6 is a conceptual diagram illustrating a material shape example when a Charpy impact test piece is prepared by the method of the present invention.

FIG. 7 is an example of the shape of a Charpy impact test piece.

FIG. 8 is an explanatory view of an example of processing steps of a Charpy impact test piece according to the method of the present invention.

FIG. 9 is a projection enlarged photograph (magnification: 38 times) of a V-notched portion of a Charpy impact test piece which has been V-notched by the method of the present invention, observed from the cutter entry side.

FIG. 10: Charpy with V-notch processing by the method of the present invention
It is a projection enlarged photograph figure (magnification: 38 times) which observed the V notch processing part of an impact test piece from the cutter exit side.

FIG. 11 is a conceptual diagram illustrating a preferred example of a Charpy impact test piece notch processing according to the method of the present invention.

FIG. 12 is a conceptual diagram of an example of processing equipment for carrying out the method of the present invention.

[Explanation of symbols]

 1 Test piece 2 Fixing jig 3 Notch cutter 4 Indentation flaw 5 Burr 6 Dummy material

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[Procedure amendment]

[Submission date] March 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

FIG. 4 is an enlarged metallographic photograph (magnification: 38 times) of a V-notched portion of a Charpy impact test piece, which has been V-notched by a conventional method, observed from the entry side of the car.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

FIG. 5 is an enlarged metallographic photograph (magnification: 38 times) of a V-notched portion of a Charpy impact test piece which has been V-notched by a conventional method, as observed from the entry side of the car.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

FIG. 9 is an enlarged metallographic photograph (magnification: 38 times) of a V-notched portion of a Charpy impact test piece which has been V-notched by the method of the present invention, observed from the entry side of the car.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

FIG. 10: Charpy with V-notch processing by the method of the present invention
It is an enlarged metallographic photograph (magnification: 38 times) of the V-notched portion of the impact test piece observed from the entry side of the cart.

Continued Front Page (72) Inventor Kazuo Nakamura 2-32 Higashitakami, Nagaoka City, Niigata Prefecture Tokki Corporation

Claims (1)

[Claims] 1. A method of manufacturing a Charpy impact test piece, wherein a notch portion is formed by cutting a groove in the test piece,
Charpy, characterized in that a notch groove is made after attaching dummy materials for sandwiching the test piece to both ends in the notch advancing direction.
Fully automatic processing method for impact test pieces.