無段式躺椅之尺寸合成設計研究

已商品化的一種無段式躺椅，其尺寸合成方法仍缺乏任何文獻記載，因此本論文提出其尺寸合成方法的初步研究。由於該無段式躺椅利用使用者的重量來實現無段式的多個位置平衡，因此人體重量作用於該躺椅的分佈是初步瞭解其平衡的關鍵。本研究首先利用簡單的沙包實驗，進行模擬人體重量作用於無段式躺椅的量測，初步實驗的結果發現作用於椅背的重量大約為總體重之43~46%、作用於椅墊的重量大約為38~41%、而作用於腳靠的重量約為15~17%，此結果並不等於直接利用標準的人體肢段重量相加。依據此實驗結果及力矩平衡方程式，可用以驗證達成無段式平衡的需求。依據已知躺椅各部份習用的桿件尺寸後，本研究試圖以解析法找出躺椅機構之地桿與其它桿件連接之旋轉接頭的位置，使其能達到無段式平衡的功能。本研究利用Mathematica軟體輔助多個平衡位置聯立方程式的求解，得出固定旋轉接頭位置的解，再輔以力矩平衡方程式而確認是否符合無段式平衡的要求。依據一無段式躺椅商品的桿件尺寸，以所提出的方法進行合成地桿與其它桿件連接之旋轉接頭的位置，結果符合該商品的固定旋轉接頭位置，因而初步證實該方法是可行的。

關鍵字

無段式躺椅；力矩平衡；向量迴路方程式

並列摘要

Though a stepless-adjustment recliner has been commercialized for many years, there is no literature on its dimensional synthesis. This thesis presents a preliminary study on the dimensional synthesis of the stepless-adjustment recliner. It is considered the stepless-adjustment recliner applies the user’s own weight to achieve many equilibrium positions. How the real distribution of user’s weight on the recliner, therefore, should be the key factor to equilibrium. Thus, this study firstly performed a simple experiment with sand bag to simulate the body weight on the recliner. The preliminary results show that the weight applied on the back of recliner is about 43-46% of body weight, 38-41% of weight on the cushion of recliner and 15-17% of weight on the footrest. The results are not just equal to the weight directly summed up by related portions of body. With the results and the equilibrium equations, the equilibrium positions of the recliner can be checked. Based on the conventional link dimensions of a recliner, this study aims to locate the required positions for the two revolute joints of fixed link to achieve the function of stepless adjustment. From two or three equilibrium positions of the recliner, it can be derived a set of nonlinear equations, respectively. This study uses Mathematica software to solve the set of nonlinear equations and obtains the locations of two fixed revolute joints. The results are then checked by the equilibrium equation of moment. The proposed analytical synthesis method has been tested by a current commercialized recliner. The result confirms the feasibility of the dimensional synthesis developed in this study.