Reasons and solutions for flipping and twisting of metal stamping parts

With the refinement of industrial electronics, various industries have increasingly high requirements for hardware stamping parts, including the shape of stamping parts. During the punching process of its appearance, it is easy to produce flipping and twisting phenomena, which affect product quality

(1) Reasonable mold design. In progressive dies, the arrangement of the cutting sequence may affect the accuracy of stamping parts. For the cutting of small parts of stamped parts, generally, a larger area of punching is arranged first, and then a smaller area of punching is arranged to reduce the impact of punching force on the forming of stamped parts

(2) Press down on the material. Overcoming the traditional mold design structure, a material holding gap is opened on the discharge plate (i.e. when the mold is closed, the discharge plate is in contact with the concave mold, and the gap between the discharge plate and the concave mold at the material holding point is t-0.03-0.05mm thick). In this way, the unloading plate moves smoothly during stamping, while the material can be compressed. The key forming part of the discharge plate is made into a block structure to facilitate solving the wear (compression) damage caused by long-term stamping on the pressing part of the discharge plate, which cannot compress the material

(3) Add strong pressure function. Thicken the size of the unloading insert pressing part (normal unloading insert thickness H+0.03mm) to increase the pressure on the material on the concave die side, resulting in flipping and twisting deformation of the stamped part during punching

(4) The end of the convex die edge is trimmed with an inclined or curved surface. This is a method to slow down the punching force. Reducing buffering and cutting force can reduce the tensile force on the side material of the concave mold, thereby achieving the effect of flipping and twisting of the stamped part

(5) In daily mold production, attention should be paid to maintaining the sharpness of the punching convex and concave die edges. When the cutting edge is worn, the tensile stress on the material will increase, resulting in an increased tendency for the stamped part to flip and twist

(6) Unreasonable or uneven punching gaps are also reasons for flipping and twisting of stamped parts, which need to be overcome

In the progressive die, metal stamping parts are formed by cutting the remaining material around the stamping part to form the shape of the stamping part. The main reason for flipping and twisting of stamped parts is the influence of punching force. During punching, due to the existence of punching gaps, the material is stretched on one side of the concave die (material warps upwards) and compressed on the side of the convex die. When using a discharge plate, use the discharge plate to press the material tightly to prevent the material on the concave side from warping upwards. At this time, the stress condition of the material will change accordingly. As the pressure of the discharge plate increases, the material on the convex die side is stretched (the compression force tends to decrease), while the material on the concave die surface is compressed (the stretching force tends to decrease). The flipping of stamped parts is caused by the stretching of the material on the concave die surface. So when punching, pressing and compressing the material is to prevent flipping and twisting of the punched part

Reasons and solutions for flipping and twisting of metal stamping parts:

1. Burrs generated during stamping.

. Need to study the cutting edge and pay attention to checking whether the cutting gap is reasonable

2. During stamping, flipping and twisting deformation of the punched parts have occurred, resulting in poor forming after bending. It is necessary to start from the punching and cutting station to solve this problem

3. It is caused by the instability of the stamped part during bending. Mainly for U-shaped and V-shaped bending. The handling of this issue involves guiding the stamped parts before bending, guiding them during the bending process, and pressing the material during the bending process to prevent slippage during bending