Site:               Asama Giken Company Ltd.
                    450 Mimitori, Komoro City
                    Nagano 384, Japan

Date Visited:       January 12, 1996

WTEC Attendees:     H.W. Hayden (report author), T.S. Piwonka

Hosts:              Dr. Sukehisa Niwa, Senior Managing Director
                      Tel: (81) 0267-228111; Fax: (81) 0267-228223
                    Kazumichi Miyamoto, Second Plant Manager and Chief
                      Engineer, Tel: (81) 0267-228118 
                    Hikuyusi Uchimi, Engineer, Tel: (81) 0267-228118

BACKGROUND

The Asama Giken Co. Ltd. is a member of the Honda family of companies. It operates two plants in Komoro City, Japan. The older "main" plant was started in 1973 and has a nominal capacity of 4,500 tons/month. The newer Misato factory, which we visited, was started in 1988 and has a nominal capacity of 2,000 tons/month. In 1996 Asama Giken opened a new plant, P.T. Asama Indonesia Manufacturing in Carawan, Indonesia, with a capacity of 400 tons/month. The company presently is considering locating a plant in the United States, either in Indiana or Michigan, with a projected start up in 1997. Asama Giken is a producer of nodular iron products primarily for the automotive industry. These include brake drums, brake disks, exhaust manifolds, knuckle arms, caliper bodies, brackets, cylinder sleeves, and universal flywheels.

RESEARCH AND DEVELOPMENT ACTIVITIES

Asama Giken appears to be active in the application of the Komatsu fine element program, "SOLDIA," for simulation of solidification for the optimization of mold and gating designs. The software includes capabilities for heat and fluid flow, calculation of cooling rates, and applications of the Niyama criteria for shrinkage. The program is run on a Sun workstation and about 24 hours of running time are needed for each simulation run. In orders from Honda, all design data for exhaust manifolds are received in digital form on diskettes with drawings.

A major development effort relates to the production of thin-walled exhaust manifolds for Honda. Asama Giken has been successful in reducing the manifold thicknesses from 6 mm to 3 mm. However, the newest target is 2 mm. At this thickness company engineers cannot achieve the desired property levels using ductile iron. They feel they have a practical limit of 4% Si in their ductile iron product using their present gravity methods. They indicated that about 5% Si would be needed to achieve property targets. As a result they indicated that the thinner manifold would have to be cast stainless steel because of improved thermal fatigue, oxidation, and corrosion resistance, with serious competition from stamped 13% Cr steel.

PRODUCTION APPLICATIONS

The new Asama Giken plant was designed for production levels of 2,000 tons/month. It was producing about 1,500 tons/month of nodular iron products at the time of the WTEC visit. It employs about 80 people in operations with two production shifts and one maintenance shift.

The plant has an automated sand preparation system which automatically controls additions of silica sand, binders, and water. Mixing is done in a Eireich high intensity muller. No seacoal or other carbonaceous materials are added to the sand, although a cushioning agent (unspecified) is used. Automatic systems are used for the measurement of moisture, permeability, compressive strength, and compactability. The system calculates changes in the sand mixture when required.

Mold making can be done on three lines. There are both jolt and squeeze and blow and squeeze machines. WTEC team members observed operations of the Sinto Sietsu impact cope and drag machine (900 mm x 900 mm x 200 mm x 200 mm) capable of producing 200 molds/hour. We were told that pattern changes can be made in less than one minute. There is also a Disa line, which we did not observe in operation.

Melting is carried out in a 24 ton cupola furnace with transfer to an induction-powered holding furnace. An automated transfer vehicle is used to move metal from the holding furnace to the mold station. The Fischer method for nodularization with pure magnesium metal is used along with inoculation in the molds. The layout of the melting area appears very efficient. The spectrograph is located close to the furnace. A three-dimensional computer controlled system is used for the storage of intermediate products.

Inspection procedures included x-ray testing for shrinkage cavities and cracks, ultrasonic testing for shrinkage cavities, and magnetic testing for cracks. The production of high quality products was emphasized strongly throughout the operation.

Asama sells the fines from its waste sand to the cement industry. The bulk of the sand is recycled through sale to a resin-bonded core supplier to Asama's own operations. The remaining 10% to 20% is disposed of in landfills at a cost of ¥7,000 to ¥10,000/ton. Cupola slag is sold to the cement industry.

Asama Giken plans to begin foundry operations in the United States in 1997 at a site in either Indiana or Michigan. Honda U.S. and Canada will be the principal customer for the plant with a projected capacity of 700 tons/month. An investment of $30 million is anticipated. The company plans to build the cleanest foundry in the United States. Because of the lower costs of labor and energy in the United States, the new plant will not be as automated as the Misato plant: electricity costs in Japan are roughly three times those in the United States.

Asama Giken representatives indicated that the labor cost including all benefits for their foundry workers is about ¥600,000/month (about $72,000/year at an annual exchange rate of ¥100/dollar). Over the past 10 years labor rates have increased about 40% at an annual rate of 3% to 5%/year. Recently, wage increases have been lower due to the Japanese recession. They suggested their labor rates are higher than in most of the Japanese foundry industry.

Asama Giken does not project conversion from nodular iron to cast aluminum as its future competitive threat from automotive down-weighting. Honda, its major customer, has virtually completed conversion from steel to aluminum. Instead, major competition will come from stamped stainless steel components which will permit decreased weight, albeit at higher costs.

REFERENCE

Asama Giken brochure.


Published: March 1997; WTEC Hyper-Librarian