Yahata Seiko Co., Ltd.

Background

Challenges unique to thick plate welding

Yahata Seiko's customers include major manufacturers of construction machinery, with thick plate welding accounting for 70% of their total welding work. The key to thick plate welding is high durability and reliability. To achieve these, deep penetration and long leg lengths are required. Since workpieces will be rejected if the penetration depth is even slightly below the specified value, the selection of welding robots and welding methods was extremely important.

Difficulty in securing skilled welders

It is not easy to secure skilled welders in the welding industry where welding is often referred to as "craftsmanship." Yahata Seiko has many workers with no welding experience; therefore, they had to use welding robots to ensure that anyone can achieve high-quality welding.

Reason for introduction

High completion level of standard welding conditions

"Panasonic's standard welding conditions are more stable than other companies'." (Mr. Yutaka Yamashita)
In the past, 50% of Yahata Seiko's robots were from other companies, and the other 50% from Panasonic. However, the Panasonic robots had more sophisticated standard welding conditions and required almost no modification to the welding conditions. This was a major decisive factor in selecting TAWERS for their sites, where many workers had no experience with manual welding.

Easy introduction at overseas sites

Yahata Seiko has sites in China, Thailand, Indonesia, and the US. Mr. Yamashita, who is in charge of overseas technical support, states, "It is very difficult to secure welding technicians outside Japan. However, TAWERS supports three languages including Japanese, English, and Chinese. As long as the workers learn basic robot operations, the robots determine the detailed welding conditions, making it possible to train local technicians in a short period of time. All robots at our sites outside Japan are TAWERS." (Mr. Yutaka Yamashita)

Benefits of introduction

100% duty cycle achieved

With the previous 350 A robots, the rated duty cycle was sometimes exceeded, causing the robots to stop. However, with the TAWERS WGH series (high power 450 A type), the company achieved an environment where the robots operate continuously.

Experiencing high-quality welding

"Our top recommendation is the HD-Pulse welding method! It enables both deep penetration and low spatter welding even on thick plates. The thick-plate industry demands high guaranteed penetration values. However, since we started using high power TAWERS, we have received virtually no complaints about penetration!" (Mr. Yutaka Yamashita)
The HD-Pulse welding method performs "1 drop by 1 pulse" control to maintain deep penetration, even under conditions where welding with a normal pulse tends to result in shallow penetration, while achieving a good bead appearance that is only possible with the HD-Pulse method.

*Spatter: Spatter refers to the small droplets of molten metal that are scattered during welding (sparks). Low-spatter welding is required because once spatter has settled on the base metal, it is difficult to remove.