Spring is an elastic element widely used in the mechanical and electronic industries. The spring can produce greater elastic deformation when loaded, converting mechanical work or kinetic energy into deformation energy, and the deformation of the spring disappears and returns to its original shape after unloading. Deformation energy is converted into mechanical work or kinetic energy.
1. The main functions of the spring are:
① Force measurement, such as spring scales and gauge springs;
②Control movement, such as clutch, brake and valve control spring;
③Vibration reduction and buffering, such as buffers, springs of shock absorbers, etc.;
④ Energy storage or energy transmission, such as springs on clocks, meters and automatic control mechanisms.
2. Type of spring:
There are many types of springs, such as compression springs, extension springs, torsion springs and metal wire forming.
3. The name and size relationship of each part of the spring:
(1) Talk about spring wire diameter d: the diameter of the steel wire used to make the spring.
(2) Spring outer diameter D: the maximum outer diameter of the spring.
(3) Spring inner diameter D1: the minimum outer diameter of the spring.
(4) Spring diameter D2: the average diameter of the spring. Their calculation formula is: D2=(D+D1)÷2=D1+d=D-d
(5) t: Except for the support ring, the axial distance between the corresponding points of two adjacent coils of the spring on the pitch diameter becomes the pitch, which is represented by t.
(6) Effective number of turns n: the number of turns that the spring can maintain the same pitch.
(7) Number of support turns n2: In order to make the spring work evenly, to ensure that the end of the axis is vertical, the two ends of the spring are often tightened during manufacturing. The number of tight turns only serves as a support and is called a support ring. Generally there are 1.5T, 2T, 2.5T, and 2T is commonly used.
(8) Total number of turns n1: the sum of effective number of turns and support ring. That is, n1=n+n2.
(9) Free height H0: the height of the spring without external force. Calculated by the following formula: H0=nt+(n2-0.5)d=nt+1.5d (when n2=2)
(10) Spring unfolding length L: The length of steel wire required to wind the spring. L≈n1(ЛD2)2+n2 (compression spring) L=ЛD2n+ hook extension length (tension spring)
(11) Spiral direction: there are left and right rotations. Right-handed is commonly used, and right-handed is generally used if it is not indicated in the drawing.
4. The prescribed drawing method of the spring:
(1) On the view of parallel coil spring lines, the contour lines of each circle are drawn as straight lines.
(2) If the effective number of turns is more than 4 turns, you can only draw 1 to 2 turns at both ends (not including support ring). The middle is connected by a dotted line through the center of the spring wire.
(3) On the drawing, when the direction of rotation of the spring is not specified, the coil spring is drawn as right-handed, and the left-handed spring is also drawn as right-handed, but the word “left” should be marked.