Circle measuring device

The utility model provides a circle measuring device, including cup jointing the triangular frame on circular sections spare, the setting is at the first thimble of triangular frame's first edge, the setting is at the second thimble of triangular frame's second edge, adjustable length ground sets up the third thimble at triangular frame's third edge, and first thimble, second thimble and third thimble can offset with the three of the same cross section of circular sections spare respectively. The utility model discloses an obtain the three of the same cross section of circular sections spare, the continuous inscription triangle -shaped who forms through the corresponding formula of triangle -shaped mathematics theorem formation, reachs the radius of circumscribed circle, and then obtains the circularity of circular sections spare to the deflection of supervise circular sections spare. 本实用新型提供了种圆度测量装置，包括能够套接在圆形部件上的三角框架；设置在三角框架的第边上的第顶针；设置在三角框架的第二边上的第二顶针；长度可调地设置在三角框架的第三边上的第三顶针，第顶针、第二顶针和第三顶针能够分别与圆形部件同横截面的三个点相抵。本实