A Study of Improvement on the Diaphragm's Gas Permeability in the Accumulator

We have developed a diaphragm which has low gas permeability and is used in the accumulator for the automotive hydraulic brake system, adopting the sandwich structure of rubber and resin films. Improvement of the diaphragm's gas permeability is absolutely necessary to achieve a maintenance-free and also light-weight and small-sized accumulator used for the automotive hydraulic brake system. We will discuss the development of the new resin films and investigation of the design factors of the accumulator focusing on the low gas permeability and durability under low temperature conditions.