Yahagi Industries’ Manufacturing

Head Office Plant

7-2 Hirokute-cho, Toyota City, Aichi Prefecture 471-0036

The plant was completed in 1964 and started operation as the headquarters the following year. It produces parts that are ready to be assembled into vehicles. The plant is divided into a fluororesin coating department mainly for engine parts and a resin molding department for engine areas, and also manufactures mass-produced products called small-volume products. It also serves as a shipping base for products from the Mifune and Fujioka plants to their destinations.

Resin

Fluorine Coating

General Manager, 1st Manufacturing Department,
Yoichi Okamura

The main plant produces mass-produced parts used in production vehicles on a daily basis and has two main divisions. First, the painting department oversees painting washers for gear bearings inside the transmission and plates for differential gears controlling the inner wheel. The difference between this coating and ordinary paint is that the driving parts are affected by heat and friction, and so they are treated with a functional coating.
Meanwhile, the resin division manufactures plastic parts. The cooling hose connectors for the engine and radiator must not leak water. Likewise, the resin formed functional parts inside the oil pump require heat resistance, durability, and strength. As the quality requirements for parts are quite detailed, we currently check the process manually, but are gradually moving towards automation. Parts that were once made of iron or aluminum are now being replaced with resin to reduce weight and cost, and I think this will continue to increase in the future. It has also become an important base for the small-lot, high-mix, low-volume production that we have been focusing on recently.

Using a robot called COBOTTA, the trajectory is commanded by computer, and the parts are set.

Resin mold maintenance. Frequent removal of accumulated impurities due to air entry, improve the precision of the parts.

Heat is a key factor in resin molding, so temperature control is specific, and timing, such as the speed of injection, is also regulated.

Spray Painting. Painting that cannot be done by machines or assembly line work is still done by hand.

Appearance inspection machine work. Painting done on the conveyor belt is checked and scrutinized using a camera.

The undercover is assembled using a jig, a support device that facilitates each parts’ fabrication process.

Meetings are held before noon and in the evening. Sales, the Quality Assurance Department, and Logistics share information to make delivery arrangements.

The quality control department in the head office inspects every single prototype part from various angles over several days.