Basic positioning of bending machine
CNC bending machines generally use a back gauge to position the work piece.
The basic principle is that during the bending process, prepared bending program first. The work piece shape is input into the machine tool, and the position of the work piece bending line is automatically calculated by the machine tool. The CNC system controls the servo motor, and the two back gauges are moved to the bending positioning position by the high-precision screw nut pair. The operator only needs to align the positioning edge of the work piece with the back gauge of the bending machine to complete the positioning process. At this time, the middle line position of the bending machine die is the bending line of the work piece. The state of the work piece during positioning is shown in figure-1.
Figure-1 work piece position
Limitations of the bending machine positioning device
It is found in production that when using the back gauge positioning for CNC bending machines. If the size of the positioning edge of the processed work piece and the back gauge is too short, it is difficult to align the work piece with the back gauge during positioning(See Figure 2). A slight left-to-right deviation of the work piece will cause inaccurate positioning. Which will cause problems such as excessive work piece scrapping or uneven bending edge dimensions. Operators need to repeatedly align to ensure the first-time forming effect. But the effect is often Not ideal, seriously affecting production efficiency and product quality.
Figure 2 Positioning of narrow and long work pieces
Positioning optimization of narrow and long work piece machining
Structure of positioning optimization device
Based on the consideration of the limitation of the positioning device of the CNC bending machine. A designed positioning optimization device that can be used for the CNC bending machine(Figure 3). The back plate is used for tight positioning with the side of the bending machine die. The locking block is used to cooperate to lock the entire device on the bending machine die. The front plate is used to install the screw. The locking screw is used to fix the movable locking block to the lower die of the bending machine. The positioning top plate is used for work piece positioning.
Figure 3 Positioning optimization device
Use of positioning optimization devices
When using the above-mentioned positioning optimization device, it is firstly aligned and clamped on the bending machine die. The state is detected by using a square ruler. When the positioning optimization device is used to locate the work piece with the back gauge of the bending machine, By holding the end of the work piece against the back gauge of the bending machine, and using the positioning optimization device on the side of the work piece. It will achieve accurate and stable positioning of the work piece(Figure 4).
Figure 4 Coordination of back gauge and auxiliary positioning device
Implementation effect of auxiliary positioning device
⑴Improved production efficiency. Before using this device, narrow and long work pieces often need to be repeatedly measured to ensure accurate positioning and it has large errors. After using this device, the operator can quickly align the work piece to be processed, which greatly improves the production efficiency of the product. It saves more than half of the production processing time for a single work piece.
⑵Improved product quality. Before use this tooling, the defective rate of narrow and long work pieces is high. The processed work pieces often have excessive bending edge scraps and uneven bending edge sizes. After using this optimization device, the quality problems caused by the inaccurate positioning of the bending lines have not occurred again, which has greatly improved the product quality.
