JP2005144545A - Hole finish method by press for round or irregular hole in blank for thermal stress removal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To resolve the problem that as a hole finish method after heat treatment, a machining work using a lathe or a horning work has been employed heretofore, or a soft nitriding treatment by a low temperature quenching in which carburize-quenching is performed after applying carburize-preventive treatment before heat treatment to restrain the development of hole strain has been employed, however such a conventional method is expensive. <P>SOLUTION: A hole finish method by a press is disclosed by which after general inexpensive heat treatment, a general press is used, and the hole finish having high accuracy at one stroke-pressing can be easily performed inexpensively, the accuracy after the finishing having such a degree that a squareness of the finished hole to the plane of a blank and a roundness of the hole at a portion becoming an elliptical hole are increased and the mirror-finishing having ≤1.5 S roughness of a circular wall is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention uses a press machine in the case where one or a plurality of round holes or irregularly shaped holes are quenched in one part of the material and thermal distortion occurs in the holes and a highly accurate hole is required. The punch is slightly larger than the material hole learned from the material hole shape that has a taper part, a land part, and a relief part on the bottom surface of the punch. Press hole Sarae processing method that processes and finishes the precision to a specified dimension.

The conventional processing method is a method for performing precision hole finishing by cutting or performing hole finishing by honing in processing related to material hole distortion removal after heat treatment. However, since finishing the irregular hole is difficult with the above-described processing method, it has been escaped by a method of performing low-temperature nitriding heat treatment that does not distort the material among the types of heat treatment. This nitriding treatment requires a high cost compared with the heat treatment for general mass production.

  The present invention is completed by subjecting the processed material to heat treatment at the end. However, when high accuracy of the material hole is required, the above-described cutting, honing, or charcoal-proofing treatment is performed as a secondary processing. After that, it was necessary to perform carburizing quenching or soft nitriding heat treatment.

Means for Solving the Invention

In the present invention, the material hole finish after the heat treatment is processed into a specified hole error by one-stroke processing using a general-purpose press.
The material processing hole is a press hole salae processing method capable of simultaneously improving the perpendicularity and roundness with respect to the material plane and the mirror surface finishing of the peripheral wall of the hole of Arasa 1.5S.

The invention's effect

  As an effect of the present invention, compared to the conventional cutting method, honing method, and soft nitriding heat treatment method, the equipment investment cost is low and the production efficiency is high, so that barrier-free production planning is possible.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a front view of a hole Sarae mold, while FIG. 2 is a shape diagram of a material for hole Sarae.
Explain and disclose hole punching using a general-purpose press.

  A material is set on the die 6 and the punches 1 facing each other are installed on the upper side. In this example, the thickness of the material is 15 mm, the outer shape is a rectangle of width 30 mm × length 100 mm, and one hole is φ30.00. The other holes are φ16.00 mm after carburizing and quenching, and the two holes are approximately 20 μ ellipse holes. This is a hole Sarae process that is performed to improve the ellipse holes into a perfect circle.

  In this embodiment, the punch 18 was used for processing. When the blank 13 is set in the recess 15 of FIG. 3 and the press starts to descend and reaches the top of the die, the stripper projection 3 first presses the upper surface of the blank 13. The stripper applies a strong pressure downward from the stripper by the upper pressure body 4. Since the outer periphery of the material 13 is blocked by the concave wall of the die and the clearance is zero near the machining hole, if the clearance occurs between the outer periphery of the material and the concave wall here, the roundness of the hole is impaired, so even a little To help, strong pressure is applied from the upper stripper convex part, and the material is kept in a stationary state without moving slightly.

  When the punch lower surface portion 11 enters the material hole, the material starts to be processed in a stopped state before and after the left and right. The punch further descends, reaches the die bottom hole blade portion, and reaches the lowest point of the press when the punch land portion 22 passes through the die bottom hole blade portion. After that, only the punch rises without releasing the material.

  At this time, a small reverse taper portion 21-2 is arranged between the punch land portion 22 and the relief portion 23, and the role of the small reverse taper portion 21-2 that occurs when the press is lowered on the inner peripheral wall of the hole when the punch is raised is reduced. It has the role of removing distortion, and the purpose is to correct the minute distortion until the punch rises from the material hole and leaves.

  The surface of the carburized and hardened material is hardened with HV670, and the hard part is made with a super steel alloy, and the surface is subjected to soft nitriding treatment for about 1 mm from the punch surface. Was subjected to ion nitriding treatment such as TiN, TicN, and CrN. In this example, TicN triple coating was used. These soft nitriding treatments + TicN triple coatings have an effect more than expected, and can prevent punch breakage or die breakage, enabling stable production.

The hole diameter accuracy of the holes after processing succeeded in achieving the expected result of ± 10 μm, and the hole wall Arasa was able to finish surprisingly beautiful at 1.5S.

It is a front view of the press punching die for hole Sarae. The figure which looked at the shape of the material for hole Sarae from the top is shown. It is a figure which shows the center recessed part and hole blade part of die | dye. It is the figure which drew four types of punch lower surface part shapes. The material drawing which finished hole Sarae processing is shown.

Explanation of symbols

1. . . . Punches 2 . . . 2. Stripper . . . Stripper convex part4. . . . 4. Upper pressure body . . . Mini guide post ６． . . . Dice 7 . . . Dice recess 8. . . . Die blade 9. . . . Material knockout pin 10. . . 10. Knockout push-up disk . . Bottom surface of the punch 12. . . Mold guide post 13. . . Material shape 14. . . Holes in material 15. . . Dice recess bottom 16. . . Die hole blade 17. . . First punch 18. . . 18. First punch lower surface taper portion . . First punch straight part 20. . . Second punch 21. . . 2nd punch lower surface taper part 21-2. . . Second taper small reverse taper portion 22. . . Second punch land portion 23. . . Second punch relief 24. . . Third punch 25. . . Third punch bottom hemispherical shape26. . . Third punch relief 27. . . Fourth punch 27-2. . . Reverse taper portion on the lower surface of the punch 28. . . Fourth punch maximum diameter portion 29. . . Fourth punch relief 30. . . Material Completion Drawing 31. . . Hole completion drawing

Claims (7)

  The center surface of the die has a concave engraving similar to the entire circumference or part of the outer peripheral contour of the die, which is within 1 mm in diameter from the outer peripheral contour of the raw material. The clearance between the material and the material is from one or more places to the entire circumference.   At the bottom of the concave part of the die material dropping contour shape, there is a punching hole part for punching hole for material hole Sarae processing, and the hole is a Sarae shape hole with a diameter within 0.02mm to 0.5mm from the punch diameter After processing, the round punch or irregular shaped punch enters the die shaped hole, and has a knockout pin, material shape, or smaller outer peripheral shape in the part excluding the round shaped or irregular shaped hole. A knockout plate is prepared in the die recess and has a function of discharging through the lower knockout pin.   A taper portion of 60 degrees or less from the tip center point is installed from the tip portion of the punch facing the die toward the cylinder portion, and the contact between the punch cylinder portion and the tip taper portion is joined at the R portion or the C portion.   The taper angle is started from the circumferential shape of the diameter of the punch tip from 50% to 90% of the diameter of the punch, and a taper portion of 60 degrees or less is installed toward the outer diameter of the punch. Or it is joined at part C, the tip of the circumferential part is a hole Sarae processing part, the length of the maximum diameter is 40% or less of the punch diameter, this part is called a land part, and beyond that, A relief part with a thinner outer diameter is provided at 20% or less from the punch maximum diameter, and a small taper of 60 degrees or less is installed at the joint between the maximum diameter and the relief part. Connect together.   The tip of the punch has a hemispherical shape that is connected by half the diameter of the punch, and a relief part that is 20% smaller in diameter than the intersection of the hemispherical R part and the stray part is prepared. The intersection of the relief part and the R part is the C plane. Connect with.   The punch tip shape portion is formed into a tapered tapered recess shape with a taper angle from the outer periphery of the punch toward the center point of the lower surface. This angle is set to 40 degrees or less, and the connection between the outer peripheral portion and the tapered portion is set to R5 or less, and among them, an appropriate R value is selected according to the material condition, and at the same time, a tapered angle is selected.   A stripper that strongly presses the material is installed on the outer periphery of the punch, and the material pressing shape of the stripper center convex part is made smaller than the die contour concave part by 0.5 or less, the role of pushing the material into the die, It has a role to prevent fine movement of the material.

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