Papers in JOURNAL OF THE JAPAN SOCIETY FOR TECHNOLOGY OF PLASTICITY
(Vol.38 No.432 January 1997)
Simulation of Strip Crown in Cross Rolling
Analysis of Strip Crown by Rigid-Plastic FEM in Cold Rolling II
Hideaki FURUMOTO Kazuo MORIMOTO, Kanji HAYASHI and Kozo OSAKADA
(Received on December 28, 1995)
A method for analyzing the thickness distribution of a strip after cold cross-rolling based on the rigid-plastic
finite element method is proposed. The non-uniform gap distribution caused by cross-rolling and the shear
deformation in the width direction caused by the width component of the roll velocity are taken into
consideration.
It is found that the shear deformation in the width direction has a small effect on the thickness profile and
the small plastic deformation in front of the roll bite has a significant effect on the thickness profile in cold
cross-rolling, and that the method for determining the longitudinal length in front of the roll bite, proposed
in a previous report, is valid to calculate the thickness profile. The analytical results for the thickness profile
agree well with the experimental ones.
Key words : rolling, FEM, strip crown, cross rolling
Deformation Analysis of a Three Roll Reducing Mill
Tatsuya OKUI Masayuki YAMADA and Tateo YAMADA
(Received on April 23, 1996)
The mechanism of circumferential variation of wall thickness observed in a tube rolled by a three-roll
reducing mill is investigated. Deformation of a predeformed region, which is observed just before a tube
contacts the rolls, is investigated by conducting a series of model rolling tests of lead tubes and by
three-dimensional rigid-plastic finite element analysis. Longitudinal variation of wall thickness during rolling is
examined by the series of model rolling tests. Its mechanics is then discussed with respect to the stress
distribution evaluated by finite element analysis, in the deformed region. Influences of back and front tensions
on the variation of wall thickness are also investigated. The obtained results are as follows ; ( I ) Variation of
wall thickness in the predeformed region is so large that contribution of this region to what should be
considered in order to obtain adequate wall thickness after rolling. (2) The increase in wall thickness in the
predeformed region is markedat the groove side of the rolls. (3) The influence of back tension on the
variation of wall thickness in the predeformed region is more significant than that of front tension.tube, rolling, reducing mill, wall thickness, groove, rigid plastic FEM, three-dimensional
deformation
Key words :
Surface Finish by Multi-stage lroning of Extruded Aluminum Pipe
Improvement of Formability in lroning of Extruded Pipe
and 3 Dimensional Analysis of Surface Roughness
Teruie TAKEMASU, Tatsuo OZAKI, Ryoichi MATSUNAGA,
Susumu YAMASAKI, Masashi SAKAGUCHI and Minobu SUKIMOTO
(Received on April 23, 1996)
Multi-stage ironing experiments are carried out using an aluminum alloy (A3003) extruded pipe in order to
examine the applicability of the pipe and process to the production of photosensitive drums. Three kinds of
pretreatment of workpiece are tested to improve the formability during ironing of the extruded pipe: annealing
at the conventional temperature (410 Cels.), annealing at 500 Cels. and removal of the surface layer of the pipe by
turning. The pickup resistance of the extruded pipe during ironing is markedly improved by annealing at 500 Cels. .
The desired surface finish of Ry < 0.5//m can be obtained by a 3-stage ironing process. Three-dimensional
measurement and analysis of the surface profiles of the products are performed using a probe scanning
microscope. A fairly smooth surface is obtained using a 6-stage ironing process, whereas grooves about 1 micro meter
deep remain when a 3- or 4-stage ironing process is used. The shape and distribution of asperities and their
variation throughout the ironing process are illustrated using a bearing diagram. The roundness accuracy and
a thickness uniformity of the extruded pipe are demonstrated to be better than those of a deep-drawn cup.
Key words : Ironing, Extruded Aluminum Pipe, Photosensitive Drum, Annealing, Pick-up, Surface Rough-
ness, 3-Dimensional Analysis, Bearing Diagram, Accuracy
Influence of Punch Shape on Change of Sectional Shape
on Dieless Shearing of Section
Research on Shearing of Extruded Section by Low-Cost Die III
Hidetaka KIDA, Norio TAKATSUJI, Mitsugu TOKIZAWA,
Kenji MATSUKI, Kazuo MUROTANI and Nobushige DOGUCHI
(Received on May 22, 1996)
The influence of punch shape on the change of sectional shape " ~ " of a 6063 extruded aluminum alloy
section during dieless shearing has been investigated. Experiments showed that the working limitation ac-
companied with no change of sectional shape was improved by using a punch with shear angle r punch in the
end working of L model shearing. The working limitation using a punch with r of 7 degree was the highest among
those of punches with an edge angle. The change of sectional shape was controlled by using a punch with r
of 7 degree. The working limitation in the intermediate working of U model shearing was higher than that in the
end working using a flat punch. The change of sectional shape was not controlled in all section sizes by using
a punch with r of 7 degree of punch group V. Because the change of sectional shape due to the deformation on
the root of a rib in the U model shearing was occurred.
Key words : shearing, extruded section, dieless shearing, change of sectional shape, punch shape, working
limitation.
Accuracy of Determination of Three-Dimensional Coordinates and
Strain of Press Forming Products by Image Sensing Camera
Makoto SAKAMOTO, Takao SAWADA and Yukio SHlNOZUKA
(Received on June 11, 1996)
A method for calculating the three-dimensional coordinates and strain of press forming products using an
image sensing camera is shown, and the measurement error is determined. First, a method for determining
two kinds of parameters is presented; one kind of parameter represents the positions and angles of the camera
(extrinsic parameters), and the other kind represents the focal length and the shift of principal point of the
lens (intrinsic parameters). Second, the measurement error, that is, the difference between the true value and
the measured one, is determined using a numerical model which gives the coordinates of the object point and
the imaged one on the image sensing camera calculated in advance by geometric optics. The error can be
decreased when the intrinsic parameters are introduced and the technique for determining the boundary of a
black and white target on the sensor surface is improved. In a press forming experiment, the maximum error
of measurement is 0.143mm, and the average error is 0.0992mm at a distance L=2680mm of camera to the
product.
Key words : noncontact measurement, triangulation method, numerical virtual model, image sensing camera,
measurement accuracy, press forming