红外技术, 2016, 38 (8): 659, 网络出版: 2016-09-12
低温下(-213℃)补偿机构的设计
The Design of Compensation Mechanism at Low Temperature of -213℃
低温(-213℃) 光学设计稳定性 温度补偿 不锈钢变形 螺栓预紧力 热膨胀系数 at low temperature of -213℃ optical stability of optical design temperature compensation deformation of stainless steel bolt pre-tightening force coefficent of thermal expansion
摘要
为了满足光学平台在低温下(-213℃)的光学设计稳定性要求,本文设计了一种温度补偿结构,基于材料热膨胀系数随温度变化的原理对该结构进行了理论计算和实验验证。该结构通过控制螺栓的预紧力保证连接件可靠,并使殷钢板在低温下处于自由伸缩状态;并利用在低温下因瓦合金变形极小补偿不锈钢变形带来的误差。其光学系统的在低温下的指标RMS≤?/10,?=632.8 nm。理论表明,在低温下因瓦合金的最大变形量为0.24884mm,不锈钢的最大变形量为2.910mm;实验结果表明:在常温和低温下用干涉仪测得的光学系统的面形精度分别为RMS=?/13、RMS=?/12,?=632.8 nm。在低温下能较好满足光学设计稳定性要求。
Abstract
In order to meet the requirements of the optical stability of the optical platform at low temperature of -213℃, the paper designs a temperature compensation structure. Based on the theory of material coefficient of thermal expansion changes with temperature, and the theoretical calculation and experimental verification are carried out on the structure. The structure can ensure the reliability of the connecting piece by controlling the pre-tightening force of the bolt, and make the invar alloy in a state of free expansion at low temperature. And under the low temperature, the invar alloy’s small deformation can compensate some deformation error of stainless steel. The optical system index RMS≤1/10?,and ?= 632.8 nm in low temperature. Theory suggests that the maximum deformation of invar alloy is 0.24884mm at low temperature, and the maximum deformation of stainless steel is 3.001 mm; Under the normal and low temperature, the experimental results show that the surface accuracy of the optical system measured by the optical interferometer is RMS=1/13?, RMS=1/12?, respectively. At low temperature it can well satisfy the stability of the optical design requirements.
李冬冬, 胡明勇, 吴海燕, 赵金标. 低温下(-213℃)补偿机构的设计[J]. 红外技术, 2016, 38(8): 659. LI Dongdong, HU Mingyong, WU Haiyan, ZHAO Jinbiao. The Design of Compensation Mechanism at Low Temperature of -213℃[J]. Infrared Technology, 2016, 38(8): 659.