Shanghai Daoqin Plastics Co., Ltd.

machine liquid pressure system can positive as, remove system combined design, parts manufacturing quality and use and other conditions outer, liquid pressure has suitable property degree is 一 十 separation important factors. liquid pressure as is liquid pressure 传动 工 as 介质, remove can amount, also has lubricated parts 运动部位 保护 metal by and other function. especially is currently liquid pressure technology toward high pressure, formed, small type development, add upper electronics technology application, for liquid pressure system as has can property, degree, stability property and lifespan 提出 愈灭愈 high high requirements, therefore, injection molding machine liquid pressure system selection property can good, tool has relatively high degree liquid pressure use 油. 　 has material statistics 显示: has ultra- 70% liquid pressure system fault/failure is due to liquid pressure selection combined or use, tube/pipe 不善, make liquid pressure to 污染造 formed. therefore, must understanding liquid pressure system for use various requirements, combined selection, positive in 维护保 tube/pipe, can ensure liquid pressure system positive 常运行, less fault/failure, improve/increase production efficiency.
一, liquid pressure requirements and selection
　　1, liquid pressure basic requirements
（1） viscosity combined 适, tool has relatively good viscous temperature features. liquid pressure viscosity large, system pressure loss large, efficiency reduce, and abrasion loss increase, reduce use lifespan; if liquid pressure viscosity small, system easy 泄漏, system efficiency reduce, therefore, liquid pressure viscosity need selection combined 理, need large need small. liquid pressure viscosity temperature degree 变化而变化, temperature degree rise high 时, liquid pressure viscosity decline. liquid viscosity temperature degree 变化而变化 property can viscous temperature features, commonly used viscosity table/sheet 示. viscosity 指数越 high, liquid viscous temperature features good, temperature degree 变化时, viscosity relatively small. liquid pressure viscosity generally high 于90.
（2） in as temperature degree and pressure lower, tool has good lubricated property, stability property and 一定 油 film strong/high degree. liquid pressure system as device parts is need generate scratch and abrasion loss, machine 停止, 启动时, scratch force relatively large, 启动时摩 scratch force is most large, easy abrasion loss. therefore, liquid pressure need tool has good lubricated property, for 运动部 parts to lubricated function, to decrease/reduce abrasion loss, long use lifespan 目. in high temperature, high pressure, high speed conditions lower as liquid pressure system, more requirements liquid pressure need tool has good lubricated property, is has high film strong/high degree, wear resistance need good. liquid pressure in through 一 阀口, small 孔时, need strong/high 烈 剪切 function, in 此情况 lower, relatively large separation fracture, formed relatively small separation 子, formed liquid viscosity reduce, reduce to 一定程 degree 时, liquid pressure 油就不 can again use, therefore, liquid pressure tool has relatively good resistant stability property.
（3） tool has relatively good resistant oxidation property. liquid pressure system as has relatively high pressure and temperature degree, need liquid pressure in conditions lower 不变质 aging, 不析出沥青, and other 胶质沉淀.
（4） need tool has good property. liquid pressure in mixed has gas is very has 害, in system as generate function, formed impact 波, this type of impact force and impact as used for solid 体壁面 upper, generate gas function, make device parts loss bad. another, bubbles pressure speed pressure shrink, generate local high temperature （据计算, can 达几百 degree above ）, will add fast liquid hot separation understanding, and oxidation, make liquid 变质, 变黑.