Adapting and taking measures to prevent climate change, which poses a threat to human security that transcends national borders, are shared global challenges. As a company that operates globally, we are committed to reducing the environmental impact of our business activities, thereby contributing to the resolution of climate change and the development of a sustainable world.
Our approach to climate change
We at TOKYO KEIKI are strongly aware that the impact and risk posed by climate change to our businesses and all of our stakeholders are important business issues. In order to fulfill our responsibility as a company to mitigate climate change, we are promoting initiatives to reduce GHG emissions from each of our divisions.
Specific measures to fight climate change
More efficient energy use to reduce GHG emissions
In hardware terms, we are replacing plant equipment with that which emphasizes energy efficiency. Specific measures include switching to LED lighting and energyefficient air conditioners, replacing power receiving equipment with high-efficiency devices, introducing energy-efficient transformers, upgrading air compressors to inverter systems, using thermal barrier paints on roofs and exterior walls, and using “green curtains” of plants to reduce use of air conditioning.
On the operational side, we are pursuing more efficient energy use through measures such as overall optimization using demand-based power monitoring, reduction of power consumption through combined heat-treatment operations, turning off lights when no one is present, making efficiency improvements to cut down operating hours, and implementing mixed loading of delivery trucks to reduce the number in operation.
Energy consumption and carbon dioxide emissions（Scope 1, 2）
Switch to LED lighting
As part of the ISO 14001 initiative, each of our plants is switching from fluorescent to LED light bulbs to reduce electricity use by an average of 1% per year, in line with the non-binding targets set by the Energy Conservation Act. With the exception of a few areas, this initiative, which started in FY 2014, was completed at the end of FY 2019, and the Sano Plant and Hanno Plant have already achieved a 100% LED conversion rate.
The Nasu and Yaita plants, which have LED conversion rates of 99% and 98% respectively, will continue to work towards full conversion.
Through the replacement of fluorescent bulbs with LEDs, we have achieved total reductions in energy consumption of 1,248,393 kWh/year at our major business sites.
Upgrading to energy-saving equipment
When upgrading or introducing new equipment for use in offices and plants, we work to reduce the amount of energy we use by selecting energy-efficient products.
When introducing new equipment, the staff member in charge selects a model and vendor after assessing the energy efficiency of multiple products, and this selection is then approved by a supervisor. At that time, the Workplace Environment Officer also checks the relevant legal regulations, and the results are reported to the Environmental Management Officer for approval via the Environment Office.
Sequential replacement of water-cooled air conditioners with energy-saving air-cooled models
Reduction of design defects
Design defects can not only lead to serious incidents, but also to significant material and energy losses due to reduced yield rates. As such, reducing design defects is also essential to minimizing environmental impact.
We are continuing our efforts to prevent design defects by conducting design reviews for all new products, existing products, and products with design changes.
For software, design management is carried out using operating procedure manuals. By creating a database of past design defect information, design defects can be shared companywide and checked as needed to prevent new design defects from occurring.
Reducing electricity use by promoting process improvement
Even with highly energy efficient equipment and the prevention of defects in the design stage, waste in production processes limits the effectiveness of energy conservation. Our Group is working to reduce electricity use in the production stage as well by eliminating waste in production processes.
The Nasu Plant boasts the largest scale in our Group. As a production site for precision mechatronics devices, in addition to assembling electronic equipment, the plant also engages in the machining of mechanical components utilizing a variety of machine tools, and here we pursue optimum work processes.
Improving hydraulic valve spool and sleeve machining
In the machining of spools and sleeves for hydraulic valves, we took on the challenge of reducing operating hours for machine tools used in sleeve polishing (lapping), something that previously required many hours.
Previously, 3μ lapping powder was used for all relevant sleeve lapping. We then switched to using 6μ lapping powder to perform a “rough” lapping before using the conventional 3μ lapping powder to perform a “finishing” lapping. This improvement resulted in a 3,498-minute annual reduction in machine tool operating hours, helping to reduce power consumption by 64 kWh per year.
Reducing machining times for internal high-precision gyrosensor components
Worm gears, screw-like gears used in high-performance gyrosensors, are produced at the Nasu Plant. The existing machining method was an issue. It involved many processes and required a lot of time. Revising the machining method to reduce the number of processes from eight to five and switching to numerical control (NC) made it possible to drastically reduce machine tool operating hours by 84%. This improvement resulted in a 1,802-minute annual reduction in machine tool operating hours, helping to reduce power consumption by 45 kWh per year.
Reducing machine operating hours for drill press processes
Aluminum sensor blocks used for high-precision inertial measurement units are produced at the Nasu Plant. Each block has 158 screw holes for mounting components, requiring numerous taps to be drilled. As this required much time, efforts were made to improve the work process. The process was changed and a switch was made from using a radial drill press to perform the work, to using two machining centers (MCs). This improvement resulted in a 2,922-minute annual reduction in machine tool operating hours, helping to reduce power consumption by 330 kWh per year.