Line fillet and pattern curves
Mates are used in many machine parts to smoothly transition lines.
To construct conjugations, you must be able to construct a tangent at a given point on the circle (Figure 7.1 a) and draw a straight line tangent to the circle from an external point (Figure 7.1 b). Remember that the centers of circles touching externally are located at a distance from the sum of their radii (Figure 7.1 c), and internally - at the distance of their radii (Figure 7.1 d), and the point of contact (conjugation) always lies on a straight line passing through their centers .
The foregoing makes it easy to understand the sequence of solutions to the conjugation problems given in Figure 7.2. ∂, e, g, i, k.
Pattern curves are traced using patterns. The following are most often used in technology:
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.1
Ellipse.
An ellipse is a closed curve for which the sum of the distances from any point to two points - the foci of the ellipse - is a constant value. To construct an ellipse, draw two concentric circles, the diameters of which are equal to the axes of the ellipse (Figure 7.3). These circles are divided into several equal parts (12-16). Vertical lines are drawn through the division points on the larger circle, and horizontal lines are drawn through the corresponding division points on the small circle. The intersection of these lines will give the ellipse points I, II, III
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.2Parabola.
A parabola is a curve, each point of which is located at the same distance from a given straight line, called the directrix, and a point called the focus of the parabola.
Given is the vertex of the parabola O, one of the points of the parabola D and the direction of the OS axis (Figure 7.4). A rectangle is constructed on segments OC and CD, the sides of this rectangle OB and BD are divided into an arbitrary equal number of equal parts and the division points are numbered according to Fig. Vertex O is connected to the division points of side BD, and straight lines parallel to the axis are drawn from the division points of the segment OB. The intersection of lines passing through points with the same numbers determines a number of points of the parabola (for other methods of constructing a parabola, see the recommended literature).
