Site:               Komatsu Ltd.
                    1-3, Shimotago
                    Toyama 935, Japan

Date Visited:       January 12, 1996

WTEC Attendees:     D. Bertram (report author), D. Apelian, G. Holdridge

Hosts:              Akira Fujii, Deputy General Manager, Foundry Division
                    Masashi Osada, Project Manager, Foundry Technology Group 2
                    Tomomichi Kato, Manager, Administrative Section, Planning


The Komatsu-Himi operation has sales of $130 million is the largest part of the ¥23 billion Foundry Division. Komatsu in total is a ¥900 billion public company employing with 20,000 people in five sectors: construction, components, industrial machinery, electronics, and software. The foundry division is part of the construction sector and operates at four locations in Japan and one each in Brazil and Indonesia.

The first Himi plant was established in 1952 and the second one in 1972 for the purposes of supplying both iron and steel castings for Komatsu's construction equipment. The two plants in Himi cover 54,000 m2, employ 485 people, and produce 5000 tons of castings per month.


Arc furnaces are the primary method of melting. A 14 ton furnace is used for steel and an 8 ton unit for gray iron. Some melting and alloy adjustment is done in coreless induction furnaces. A traditional overhead bridge crane delivers the metal. No special metal treatment is done. Ceramic filters are used in gray iron runner systems whereas no suitable filters have been found for steel. Komatsu has not identified a qualitative method to measure metal cleanliness.

The molding equipment is very modern and carries the Komatsu name plate. The equipment has a completely automated jolt squeeze unit with a circulating pattern loop that can cycle four different patterns. The mold dimensions are as follows:

     Steel foundry        1500 mm x 1800 mm x 450 mm
     Gray iron plant 1    900 mm x 600 mm x 350 mm  (Valve bodies)
     Gray iron plant 2    1100 mm x 1100 mm x 400 mm  (Cases)

Komatsu managers see automation as being the most significant development in their plant in the next five years. Concerning computers, they feel that information exchange is progressing well and that engineers and managers now have better access to data which allows more analysis. They see little change at the work station however as a result of this activity. The whole plant is on a LAN and information can be accessed from any location.

Komatsu has a very intensive training plan for each person, plant manager through lowest level. It outlines training on topics ranging from leadership, management, special and general technical subjects to safety and machine operation. Everyone gets almost two weeks of training per year.


Komatsu has developed a solidification modeling program, SOLDIA, which it has sold to 100 Japanese foundries. The program is three-dimensional and runs on a Sun Microsystems computer. The system is used at Himi to check the first design of a gating system and then relocate risers as required. The benefits include shorter lead times and fewer inspection requirements. This program does not do fluid flow analysis nor is it used for microstructure control. An English interface version is not currently available.

Komatsu Corp. has a manufacturing engineering center located in Osaka with 90 associates doing manufacturing engineering research, and an R&D center in Tokyo with a staff of 200 for fundamental research. Approximately half these people are technical.

The engineering center interfaces regularly with the plant, having two formal meetings per year. They cooperatively establish the annual development theme. The corporate organization funds this activity and does not tax the plant.

Mr. Sada regards the Material Process Technical Center located near the Tokyo Tower as a primary source of information for foundry engineers. The Japan Foundry and Engineering Association holds regular meetings on specific subjects. These meetings provide a forum for getting to know engineers in other companies and to share information.

Komatsu funds university research projects. Foundry automation is one current subject.


Komatsu is a good captive producer of steel and iron castings for the construction equipment industry. It is using its internally developed software to improve products and reduce cost. The engineers at Himi interface well with corporate counterparts to affect planned improvements.

Published: March 1997; WTEC Hyper-Librarian