Bending machine dies are auxiliary tools used by bending machines to shape and process sheet metal. These tools consist of various components, and different dies are composed of different parts and shapes. Their main function is to change the physical state of the material (mainly metal sheets) through the pressure of the bending machine, thereby achieving the desired shape of the material.
Structurally, bending machine dies can be divided into two main categories: upper dies and lower dies. In most cases, the upper die is the active die (moving die), and the lower die is the passive die (stationary die). However, there are also cases where the roles are reversed depending on the working mode of the bending machine, but the overall form remains unchanged.
From a usage perspective, bending machine dies are generally classified as standard dies and special dies. Standard upper dies typically have blade tip angles of 30 degrees (actual angles range from 26 to 28 degrees), 60 degrees, 78-88 degrees, etc. The angles of the slots in the lower dies are usually around 30 degrees, 45 degrees, 60 degrees, 80-90 degrees, etc.
Based on their shape, the upper dies of bending machines can be classified as pointed dies, arc dies, blade dies, and forming dies. Pointed dies are usually designed with angles of 30 degrees and 60 degrees, occasionally with special angles such as 45 degrees and 55 degrees. Arc dies are designed based on the diameter and arc length of the arc and can vary widely. Blade dies are mainly used for U-shaped workpieces or avoiding multiple bends. The most complex type is the forming die, which can be either integral or composite. In general, composite dies are designed, manufactured, and used as a set with both upper and lower dies. In terms of production cost, the manufacturing cost of integral forming dies is relatively higher (especially for large-sized dies), and their precision is difficult to control. Composite dies have significant advantages for large-sized and complex-shaped dies.
From a functional perspective, bending machine dies can be classified as single-function dies and multi-function dies. Single-function dies can only process a single type of workpiece, while multi-function dies can handle different types of workpieces. Some multi-function dies can be disassembled and assembled, and they are also called compound dies, such as step dies and forming dies.
Based on the number of die grooves, the lower dies of bending machines can be roughly classified as single-V dies, double-V dies, and multi-V dies. Single-V and double-V dies have one or two grooves on the surface, which are commonly used in CNC bending machines. They offer high precision due to their fixed reference point, and they can be interchanged freely. On the other hand, multi-V lower dies are mostly square dies with several grooves on all four surfaces, of varying sizes. The advantage of multi-V dies is their ability to accommodate various thicknesses of sheet metal for bending.
With the continuous progress of society and the increasing requirements for products, the demands for bending finished products and materials are also constantly improving. As a result, the development of bending machine lower dies has been ongoing. Insert-type lower dies, mark-free lower dies, and adjustable-opening lower dies have been widely used in various industries.
1. Insert-type lower dies are mainly used to increase the utilization of die materials or for bending special materials.
2. Mark-free lower dies include ball-type mark-free lower dies, flip-type mark-free lower dies, and urethane mark-free lower dies. Mark-free lower dies help prevent scratches, abrasions, and marks on the surface of the material.
3. Adjustable-opening lower dies come in several types, including insert-type, dovetail-type, wedge-type, and rack-type. In addition to increasing the utilization of die materials, adjustable-opening lower dies greatly improve work efficiency, reduce die changeover time, and reduce labor intensity.
Bending machine dies are constantly evolving, changing, and progressing with the passage of time, the progress and development of society, and the emergence of new materials and technologies. Their continuous improvement will make it simpler and faster for us to obtain the desired products, and they will serve our society to a greater extent.
