Hino Motors, Ltd., awarded the Okochi Memorial Technology Prize for producing axle housings using FCD through the world’s first simultaneous casting and joining technology

- Use of FCD realizes improved strength and weight reduction plus a 25% reduction in CO2 at the manufacturing stage -


Hino Motors, Ltd. (“Hino”) and its subsidiary Fukushima Steel Works Co., Ltd., have been awarded the Okochi Memorial Technology Prize for 2004 for their newly developed simultaneous casting and joining*1 technology for producing axle housings*2 using FCD (ductile cast iron)*3 realized through joint research.
Taking advantage of this technology, the first of its kind in the world, Hino is already using newly-developed FCD axle housings, which realize improved strength and weight reductions, in the full model change of its heavy-duty Hino Profia truck line in November 2003.

In addition, the FCD axle housings also allow a broad improvement in efficiency in the manufacturing process compared to conventional cast steel axle housings, realizing a 25% reduction in CO2 emissions and thereby alleviating the burden on the environment.

Since the finish work is normally simple and there is no need for heat treatment when using FCD, it enables outstanding productivity; however, since it cannot be welded, it has not been possible to use FCD in axle housings that have a welded structure with forged axle tubes. Success was achieved, however, in efforts to establish new technology for joining weldable steel material to FCD when casting axle housings, paving the way to the utilization of FCD as an axle housing material.

The Okochi Memorial Technology Prize is an authoritative prize with a history going back to its establishment in 1954 awarded for “notable achievements in production based on outstanding inventions or ideas acquired through research in production engineering and technology.” The award this time for its innovative approach and the high level of the technology and Hino is committed to continued endeavors to pursue innovation in technology that is“beneficial to the customer”and that “alleviates the burden on the environment.”

*1: The world's first ever technology for simultaneously joining material (steel) positioned inside of the mold with the casting

*2: Vehicle tubular shaft that connects the tires on the left and right sides. Suspension is mounted on the left and right ends of the axle housing, which support the vehicle.

*3: A cast iron alloy consisting primarily of iron with a carbon content in excess of 2.0% and containing spheroidized graphite.


【Reference Material】

Production of heavy-duty truck axle housings using FCD
- Development of simultaneous joining-casting technology

Purpose	・Utilization of high-strength FCD (ductile cast iron) offering outstanding productivity ・Development of rear axle housings for a broad improvement in the manufacturing environment
Means	Conventional (cast steel):	Excellent weldability in spite of problems with dams, sinkhead fusion, gouging (work environment) and energy yield
	Use of FCD:	Outstanding productivity in spite of problems with weldability
		Newly-developed first-ever simultaneous casting-joining technology that endows FCD with a weldability function*1
		*1: The material (steel) to be joined is positioned within the casting mold and is joined simultaneously when the casting is made
Effects	・Revolutionary improvement in productivity, elimination of finish and heat treatment processes ・Vast improvement in work environment and LCA: No need for fusion or heat treatment, 25% reduction in CO2 emissions; November 2003: full utilization in new heavy-duty trucks (patent pending)