针筒三角走针跑道的加工与设计问题探讨

INVESTIGATION INTO DESIGN AND MACHINING OF CYLINDER CAM RACEWAY IN A CIRCULAR KNITTING MACHINE

本文对目前所普遍采用的针织圆纬机针筒三角走针跑道的加工方式与设计方程不一致,以及因加工方式本身引起的跑道不良径向倾斜等问题,进行了分析探讨,提出了如下解决途径:在设计上,把方程式表示为以中心角θ为自变量函数 y=ψ(θ)。在加工上,改装数控机床或设计夹具,达到三角坯料相对刀具除保留 Y 向运动外,增加能够控制的θ角的运动,可获得精确符合方程的跑道曲线和避免跑道的径向倾斜。或者,可按文中所述规律与公式,合理选取基准线并作坐标转换,可避免不良径向倾斜产生于跑道上压力角最大处和获得正确的跑道曲线。

By investigating the deviation of the cylinder cam receway fabricated with the generalmethod for a circular knitting machine from the designed curvature equation and the inherentradial inclination of cam raceway herefrom observed,the author gives the following sugges-tion:giving the curvature equation y=Ψ(θ) in terms of the central angle θ as the independentvariable;machining the raceway precisely without radial inclination by virtue of specially de-signed numerical control milling machine and fixture,which not only permit the free motionof the blank in the Y direction relative to the cutting tool,but also facilitate the changing ofangle θ under control.Or,as an alternative by rationally selecting the base line and trans-forming the coordinates according to the rule and equation proposed in this article,the manu-facturer can also fabricate a correct profile of the track curvature free from the above men-tioned radial inclination on the track where the max.pressure angle is located.