In the metal processing industry, press brake dies are one of the key components for achieving precise machining. To ensure processing quality and the efficient operation of the machine, strict testing and adjustment of both new and old dies are essential. This article provides a detailed overview of the qualified testing methods for new press brake dies and adjustment methods for old dies, offering technicians a comprehensive operational guide.
I. Qualified Testing Methods for New Dies
The testing of new dies typically involves three main steps to ensure their performance and safety in actual use.
1. Flatness Testing
- Testing Steps
- Place the die flat on a testing platform and use a feeler gauge to check if there is any bending in the die's flatness. Generally, a bend between 0.2mm to 0.3mm is acceptable as this slight bend can be adjusted through fixtures when mounted on the machine.
- Press or tap one end of the die by hand and observe if the die moves or rotates, as these are signs of bending.
- Perform the above tests on both sides of the die to ensure the overall flatness of the die.
2. Die Height Testing
- Tools Used
- Use a vernier caliper to measure the height from the stress plane of the die to the cutting edge.
- Allowable Error
- Height error should be controlled within 0.03mm to ensure uniform height of all parts of the die for precise bending.
3. Blade Straightness Check
- Installation Check
- Install the entire set of dies on the machine and manually touch to check if the blades at the joint of the two die sections are aligned.
- Bend a full-length metal sheet through the joint and check for imprints, as well as whether the bending angle and straightness at the joint meet the requirements.
II. Inspection and Testing of Lower Dies
Similar to upper dies, the inspection of lower dies is equally important, but the tolerance for bending is lower as any lack of flatness in the lower die directly affects the bending quality.
1. Flatness and Perpendicularity Testing
- Testing Method
- Similar to flatness testing for upper dies, but with stricter requirements as once the lower die bends, it cannot be corrected on the machine.
- Use a square to ensure the perpendicularity of the four planes of the lower die.
- Check the angle and dimensions of the V-groove, ensuring basic alignment despite production errors typically being within ±0.15mm.
III. Adjustment Methods for Old Dies
The key to adjusting old dies is to ensure their perfect fit with the machine and to eliminate any wear and deformation that may occur during use.
Basic Adjustment Steps
- Alignment Check
- Ensure alignment consistency between the cutting edge and the blade after the die is mounted on the machine.
- Component Check
- Check the uniformity of the die's cutting edge size and thickness, as well as the flatness of the clamping part and stress plane.
- Reprocessing and Grinding
- For dies with obvious deformation or inconsistency, reprocessing or grinding is necessary to restore their original accuracy.
Adjustment for Height Inconsistencies
- Die Plate Adjustment
- If there are height inconsistencies in the upper die, adjusting the die plate can resolve the issue.
By following the detailed steps above, technicians can ensure that press brake dies achieve optimal performance during the production process. Regularly conducting these tests and adjustments not only prolongs the lifespan of the dies but also significantly enhances production efficiency and processing quality.
