Look at the coil spring machine from the forming principle of the coil spring
When the spring material passes through the straightening mechanism and the feeding mechanism and hits the slot at the front end of the ejector rod, the spring material is forced to bend and deform. The spring coil is wound into three friction points held by the material. For a single ejector spring coiling machine, the three friction points are the tangent points between the spring material and the wire plate, mandrel, and ejector rod; for a double ejector spring coiling machine, the three friction points are the spring material and the wire plate. , The tangent point where two curve gauges touch. In the process of bending the spring material into a loop, the steel wire will contact the inclined surface of the pitch block.
When the pitch change mechanism of the spring coiling machine moves the pitch block along the axis of the spring winding forming, the pitch of the helical compression spring is made. When coiling a helical compression spring parallel head (support ring) or a helical extension spring, the pitch block retracts to the back, and when the spring is coiled, the next coil is formed against the previously coiled coil. When a spring is rolled, the feeding mechanism stops feeding, and the cutter control machine forces the cutter to cut the spring. Such reciprocating operation realizes the automatic forming of the spring.
The curve gauge can be moved back and forth under the control of the spring diameter changing mechanism to adjust the diameter of the spring or to roll the variable diameter coil spring. When rolling a reducing coil spring, the corresponding reducing cam must be used. As the spring material is continuously rolled into a coil, the diameter-reducing cam also rotates correspondingly to control the ejector rod to move appropriately, and the required diameter-reducing coil spring is rolled.
When coil compression springs with variable pitch (commonly known as unequal pitch) or other spiral springs are to be rolled, a variable pitch cam is required; under the action of the variable pitch cam, a set of swing rod mechanism pushes the pitch block to move forward and backward, In order to realize the coiling of variable-pitch springs.
It can be seen from the working principle of the spring coiling machine: the advantage of the single ejector spring coiling machine is that it only needs to adjust a curve gauge, the machine tool adjustment time is less when changing the spring varieties, and it can coil higher initial stress. The spiral tension spring is more convenient when the left and right spiral springs are exchanged; the advantage of the double ejector spring coiling machine is that the mandrel no longer becomes a friction point of the formed coil, but only plays an auxiliary role when cutting the steel wire.
When producing springs of different diameters, there is no need to frequently exchange mandrels. In addition, the center angle corresponding to the three friction points of the double ejector spring coiling machine is also larger than that of the single ejector. Therefore, it is more convenient and stable to wind a relatively large spring. However, the double ejector spring coiling machine is very troublesome when the left and right coil springs are exchanged, and the entire outer diameter changing mechanism needs to be modified.
There are many factors that affect the quality of coil springs, such as the tensile strength, elongation, elastic modulus, yield ratio, dimensional accuracy grade and surface condition of the material, the accuracy of machine tools, auxiliary tools and metal wires. The friction condition of the contact part, the accuracy of the feeding length, the winding speed and the technical level of the operator, etc.