提出了一種以空間三自由度并聯機構作為主進給機構的并聯機床新結構。建立了并聯機床主進給機構位置分析的輸入輸出方程，推導了奇異位形判別的解析表達式。該判別式在形式上為多項式代數方程，在推導過程中引入數值-符號處理技術，得到了多項式代數方程中每一系數元素的數值-符號形式的解析表達式。主進給機構的奇異位形的集合為參數空間的曲面片，得到了奇異曲面方程及奇異曲面的截面曲線圖，給出了奇異位形分析計算的數值實例。
關 鍵 詞 并聯機床; 虛擬軸機床; 奇異位形; 解析

Abstract A new type parallel machine tool, which utilizes a 3dof spatial parallel mechanism as main feed machanism, is proposed in this paper. The input-output equation of displacement analysis for the main feed mechanism of parallel machine tool is established. An analytical expression for determining singularity configuration which is a polynomial equation is set, and the numeric-symbolic manipulating technique is introduced in the paper. Analytical expressions of numeric-symbolic form for each coefficient of the ploynomial equation are derived. The section curve graph of a singularity surface is drawn. A numerical example of singularity configuration analysis is given for illustration.
Key words parallel machine tool; virtual axis machine tool; singularity configuration; close form solution