Examples of Tokai Spring achievements

Tokai Spring Industries possesses unique manufacturing technology based on many years of experience of delivering products to customers in the machinery industry. Our plate springs are used for dynamic durability in presses, especially for applications that require large size and large load.

Problems and challenges

The customer was planning a spring-based mechanism as a prototype for the development of a vibration damping system called a “brake damper”.
One of the requirements for the mechanism was a spring with high-precision load characteristics and the ability to withstand ultra-large loads.

Solution

We received a request to design a thin plate spring to be installed in a large press machine.
The shape and dimensions of the mounting part had already been determined, and it was necessary to determine a shape that could be mounted on the mounting part
and dimensions that could be mounted on the mounting part and still meet the required load characteristics. In addition,
it was necessary to select a lubricant to ensure durability that allows repeated operation for at least 8 years (150,000 cycles) and to prevent wear of the sliding parts of the thin plate spring.

Results

We determined the spring shape that could be attached to the mounting part, but since there was no formula in the literature to calculate a thin plate spring of that shape, we first calculated the dimensions of the prototype by approximate calculations and made a prototype. Based on the load results of the prototype, the dimensions were set to 2 mm (thickness) x 43 mm (width) x 297.6 mm (length) (approximate dimensions). As for the service life, we proposed to select SUP10 steel, which has excellent durability, to confirm that the service life would be more than 150,000 cycles by calculation, and to verify this in an actual fatigue test. For the lubricant, based on our know-how we selected and proposed a molybdenum-based lubricant characterized by good wear prevention properties.