Human Assist

Dramatically reduce heavy niche work that remain on-site using PowerArm

HIGASHIMARU SHOYU CO., LTD is the leading manufacturer of light soy sauce. It is made mainly from the deep waters of the Ibo River, where the iron content is extremely low along with, Ako salt, soybeans, wheat and rice of the Harima region. The light soy sauce is an indispensable ingredient in Japanese food that values color. It seems that a lot of the company's products are now being exported to overseas markets, but this adds extra hard work that was not necessary for the domestic market. Although exports are increasing, they are still less than the needs of the domestic market. This caused a hesitation to introduce new equipment to automate the heavy work. Our human-assistance product “PowerArm” has solved these workplace problems. In this report, we asked about the background and effects of introducing the PowerArm.

Wanting to reduce workload without using robots.
Exploring flexible means

Valued by people around the world, Japanese food has been designated as a UNESCO World Heritage. Each bowl or dish features colors from season to season and gives a rich sense of the value of Japanese food. The number of restaurants that offer Japanese food overseas has increased year by year, and the light soy-sauce has been shipped to the domestic as well as overseas markets.

The soy sauce is packed in a can (approximately 18 liters), and is the same product for both overseas and domestic markets. They are also both handled by the PowerArm, but there is one difference in the shipping process. For overseas, it is necessary to put each can in a cardboard box to protect it from moisture and shocks to maintain quality and to prevent damage during transportation.

HIGASHIMARU SHOYU CO., LTD General manager of Production department Mr.Ichitaka Eiji
Mr.Ichitaka Eiji
General manager of the Production department
HIGASHIMARU SHOYU CO., LTD

Lifting a can filled with about 23 kg of soy sauce and putting a cardboard box on it which is placed on the floor is very hard work. Until now, once a week, the company gathered employees who were free to work and handled about 300 cans using human wave tactics. However, the general manager, Eiji Ichitaka, commented, "Back then, it was definitely a burden on our employees, although it was indispensable to export the products. Also, due to the heavy labor, not all the workers were suited to help out."

Though one might think that such strenuous labor jobs should be saved for automatic packing machines or robots. However, since exports quantities are still small, introducing a dedicated automated device was not an option. Moreover, robots can be used for labor saving and efficiency work if the installation position is fixed and the position of the target work is also fixed. However, Higashimaru Soy Sauce wanted a means that can be used more flexibly.

As a means to meet these demands, the company also considered the use of a hand crane, a type of human assist product that reduces the task of lifting heavy cans. It is cheaper and easier to install and operate than the automated equipment. The company was one step closer to adoption until it came to their knowledge that a danger existed in the event that the can would drop, causing the arm to jump suddenly. That is when they gave up the idea of incorporating the crane.

Reduce burden and ensure safety
without compromising work efficiency

HIGASHIMARU SHOYU CO., Deputy Head of the Manufacturing Department's Liquid Processing Division Mr. Takahashi Kenji
Mr. Takahashi Kenji
Deputy Head of the Manufacturing Department's Liquid Processing Division
HIGASHIMARU SHOYU CO., LTD

Breakthroughs were found at the site's work exhibit, "JAPAN PACK 2015," a packaging technology and equipment exhibition held in 2015. Takahashi Kenji, Deputy Head of the Manufacturing Department's Liquid Processing Division, explains about the demonstration and structure of our human-assistance product "PowerArm". "I knew that there would always be a useful place at my company's production site where there are many labor intensive work to deal with." It's not exactly what we had come up with at that point, but as we had taken into account the unique features of the PowerArm, we realized that this would help reduce the burden of the final packing process for export. This is when we started thinking about the work site and adoption.

The Higashi-Maru Soy Sauce had considered that there were two major requirements for the adoption. The first was that the burden must be reduced without reducing the work efficiency. The goal was to complete a series of work within 30 seconds per can, from lifting the can to cover it and placing it at a given location. The second was that workers need to be secured. "This was an essential condition because it was a tool that staff could use to support and use in their immediate surroundings,"says Ichitaka.

As a result, the PowerArm had cleared both of the two conditions. This is because the PowerArm had the ability to quickly adjust the supporting force when the weight on the arm suddenly changed.

When working manually, we had placed the cardboard box on the floor, and lifted the heavy can while aiming for the box opening. But with the PowerArm, the heavy can was lifted, and then the operator's hand was released from the handle and the can was kept still in the air. "We asked CKD to improve the operating handle to make it easier to work with by creating a circular shape, and installing a sensor there. The supporting force would stop so that the movement of the arm stops exactly when it detects that the operator's hand is released," Mr. Takahashi commented. By incorporating such a mechanism, it became possible to place the box on a suspended can with both hands, while dramatically improving effeciency.

In addition, when the can that was being carried falls, the assistance force can be changed quickly to stop the arm position without any further movement. In addition, we wanted to make improvements that would not pose a danger in the event of a sudden power outage or a loss of air supply, so we increased safety even further.

After Higashimaru Soy Sauce and our company's creation, a PowerArm was formally introduced in March 2018. One staff member at Higashimaru that works at the site said, "When I was doing this by hand, I was working with a load on my lower back. Now, I don't feel any burden at all."

The actual task of placing a box on the can using the PowerArm adopted by the Higashimaru Soy Sauce Co., Ltd.
The actual task of placing a box on the can using the PowerArm adopted by the Higashimaru Soy Sauce Co., Ltd.

Safer and Easier to Use
Continued Improvements

HIGASHIMARU SHOYU CO., LTD and CKD continue to make further improvements while the PowerArm is in operation. Mr. Takahashi recalls, "In the beginning, we thought that it would be more efficient to limit the freedom of movement of the 3-axis arm. However, as workers became more comfortable with its handling, the greater freedom of movement resulted in more efficiency." In addition, the PowerArm introduced by CKD originally had a longer shaft for the attachment that lifts the can to accommodate the work scene. However, the load detection sensor, which was installed on the opposite side of the shaft from where the can was attached, broke due to the leverage principle of the long shaft. At first, we didn't notice that there was a failure, but CKD worked quickly to improve it." Mr. Takahashi mentions.

Regardless of the industry, there are many cases in factories where the frequency of work is not high enough to introduce automated equipment, but forces workers to perform heavy labor. However, looking at the work efficiency of the entire factory, it is likely that such niche heavy work often hinders the overall efficiency. According to Mr. Ichitaka, by changing the hard work that remains at the worksite to something that is safe and less burdensome, "I want to create a workplace where everyone can work happily." We are confident that PowerArms can help you solve these challenges in your workplace.

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