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 aerospace and research industries. Our springs are used to control loads in outer space and other harsh environments, and in applications that require compact sizes and large loads designed to be installed on satellites.

Problems and challenges

We were asked if we could make a lightweight spring that would reduce vibration for a product in the aerospace field. Lightweight was a major requirement, but there was a limit to weight reduction that could be achieved with spring steel.

Solution

Initially, we tried to reduce the size and weight as much as possible while securing the necessary spring force using spring steel, but we could not reach the necessary level to meet the requirement. Therefore, we designed springs with a titanium alloy (Ti-6Al-4V), which has higher strength than spring steel. Regarding the weight reduction, the specific gravity of titanium alloy is about 4.4 compared to 7.85 of spring steel.

Results

In order to secure the necessary spring force, master/helper spring design was used, but even so, the weight was reduced by 40% compared to the design based on spring steel.

■ Proposed spring specifications
Material: Titanium alloy (Ti-6Al-4V)
Main spring: Wire diameter φ13 x center diameter φ99 x free length 190 x number of active turns 4.5 x total number of turns 6.5
Helper spring: Wire diameter φ9 x center diameter φ63.6 x free length 190 x number of active turns 7.5 x total number of turns 9.5