Linear projection demonstration instrument

Abstract

The invention discloses a linear projection demonstration instrument, which comprises a front surface (1), a horizontal surface (2), a lower support rod (3), an upper support rod (4), a semicircular ring (5), a spatial straight line (6), a lock catch (7), a handle (8) and a frame (9). The front surface (1) is a rectangular flat plate made of the wood material. The surface of the front surface (1)is painted white. A letter V is marked on the front surface (1). The horizontal plane (2) is a rectangular flat plate made of the wood material. One side of the horizontal plane (2) is connected withthe lower bottom edge of the frame (9), and the semicircular ring (5) is made of a thin metal rod. The two end points of the semicircular ring are hinged with the upper end edge of the front surface (1). The semicircular ring can rotate on the front surface (1). A space straight line (6) is hinged to the middle of the lower end of the frame (9). The upper end of the space straight line (6) is sleeved on the semicircular ring (5) and is matched with a projection light source to demonstrate the projection characteristics of the space straight line. Therefore, teaching difficulties caused by thelack of a demonstration instrument in teaching are solved.

Description

technical field [0001] The invention relates to a teaching demonstration device, in particular to a linear projection demonstration instrument. Background technique [0002] In science and engineering colleges, "Descriptive Geometry and Mechanical Drawing" are compulsory mechanical basic courses. In teaching, when it comes to the projection of a straight line in space, the various relative positions of the straight line to the projection surface are different. The projection of a straight line has Different projection characteristics, such as the projection characteristics of the parallel lines of the projection surface are: the projection on the parallel projection surface reflects the true length of the line, and the angle between it and the projection axis reflects the true inclination angle of the line to the other two projection surfaces. size. Because the spatial imagination of the first-year students has not yet been developed, in the system of three projection plane...

AI Technical Summary

Problems solved by technology

Because the spatial imagination of the first-year students has not yet been developed, in the system of three projection planes, it is impossible to imagine why only the parallel lines of the projection lines can reflect the true size of the inclination angle of the straight line to the other two projection planes. It is difficult for teachers to explain the true size of the inclination angle of the two projection surfaces by drawing pictures. Even many students have not mastered the geometric principles until they graduate, which seriously affects the teaching effect.

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