针对大口径宽波段高能激光发射系统使用环境复杂、激光发射间歇时间长,晶体窗口无法满足使用要求等情况,为发射系统设计了一套快门式机械窗口。该机械窗口采用聚氯乙烯(PVC)薄板作为防尘罩,利用弹簧和密封环组成半固定式滑槽,采用步进电机驱动。利用圆形薄板的大挠度变形原理,建立了防尘罩挠曲变形量与正压风载间的非线性微分方程;以中心挠度为摄动参数用摄动法求解微分方程,获得防尘罩挠曲变形量与风压载荷间的关系,并进一步求出电机的负载扭矩。由于电机的输出扭矩是一定的,为了使防尘罩抗风载能力达到最大,利用电机负载与防尘罩挠曲变形量间的解析关系式进一步优化了防尘罩的弯曲刚度。实际测试结果显示,防尘罩挠曲变形量的求解误差不超过15%;当防尘罩弯曲厚度为0.8 mm时,防尘罩可以抵御12 m/s风载作用,电机负载扭矩为0.34 Nm;开启与关闭的最短时间小于3 s,窗口运行可靠,符合设备使用要求。

As high-power laser launch system with large-caliber and multi-band has complex service environment and a long laser emission interval,and its crystal window can not meet use requirements,this paper designs an automatic shutter-type mechanical window for the laser emission system. The mechanical window consists of a Polyvinyl Chloride(PVC) sheet dust cover and a semi-permanent chute established by a spring and a pressure ring,driven by a stepping motor. Based on the large round plate deflection principle,it establishes the nonlinear differential equations for the deformation of dust cover and positive wind load. The center deflection perturbation is taken as the perturbation parameter to solve the differential equation to obtain the relationship between the dust deflection deformation and wind load and to further determine the motor load torque. Due to the certain motor load torque,the dust cover bending stiffness is optimized by using the relation between motor output torque and deformation to maximize capacity against the wind load. Experimental test shows that the solving error for the deflection of dust cover does not exceed 15%. When the thickness of the dust cover is 0.8 mm,it can resist 10 m/s wind load and the motor load torque is 0.34 Nm. The intervals of the window are stably from 2 to 3 s no matter it is opened or closed. This proposed window works reliably,satisfying working requirements.