상용차 드럼브레이크 시스템의 S/CAM 샤프트 열간단조 성형 해석

Abstract

In the hot forging process, the forging faulty product due to strain and temperature should be controlled in order to obtain sound S/CAM forging products. The forging defects that are caused by metal were strain, temperate, and inclusion. But the control of forging defects has been based on the experience of the foundry engineers In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering effective plastic strain and temperature affected behaviors. From these test, we reached conclusion as followings ; 1. This papar study an analysis results of strain, stress, temperature change and flow behaviors of materials using S/CAM shaft produced with pressure forging by superforge2007, a computer applicative program. As a result, contact with die occurs first at upper die rather than lower die and as 80% of processing progresses, matching with die necessary for moulding occurs both upper and lower areas and residual processing is analysed as a necessary processing for moulding. 2. As a result of analysing strain in hot forging molding of S/CAM using superforge 2007, it was reported that strain rate occurring in the materials caused by pressure to the upper die may differ. As 50% of processing progresses, large strain at the contact of materials with mold appeared. When 100% of contact of die with material is achieved in forging, high rate of strain appeared in overall materials. 3. Through improvement of mold for production of S/CAM whose axis shaft length differs, various kinds of S/CAM can be produced with a single die, and after heating SM45C to 1100℃- 1300℃, not cutting shape techniques of moulding products were applied with a use of hot forging. 4. When a new molding technique of S/CAM shaft was applied, more than 95% of recovery rate was achieved while 62-68% of recovery rate was achieved when a existing techniques was used. For existing S/CAM production processing, four processing stages were used, but working hours were too long and productivity was low. According to the new molding technique of S/CAM shaft developed, such disadvantages were resolved and current conditions centering on low-price policy could be improved through technological development. As a result, the effect of cost saving was achieved. 5. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.