Types of Bending Machine Dies
Bending machine dies come in several types, including L-shaped, R-shaped, U-shaped, Z-shaped, and others. The upper die can have different angles, such as 90°, 88°, 45°, 30°, 20°, 15°, and more. The lower die can have double or single slots with different widths ranging from 4 to 18V. There are also R-shaped lower dies, acute angle lower dies, flattening dies, and more. Both the upper and lower dies can be segmented or solid. The segmented upper dies are typically divided into sections of 300mm, 200mm, 100mm, 50mm, 40mm, 20mm, 15mm, and 10mm, while the solid upper die is 835mm in length. The lower dies are usually divided into sections of 400mm, 200mm, 100mm, 50mm, 40mm, 20mm, 15mm, and 10mm, with a solid length of 835mm.
Components of Bending Machine Dies
Standard bending machine dies consist of a middle plate, upper die, lower die, guide rails, lower die seat, and other parts. These types of dies have strong versatility and can be used for various processing tasks.
Different parts require different dies for processing. It is important to have an understanding of the machine tool and die processing parameters to select matching dies.
1. Choose suitable dies based on the shape, size, and inner R angle indicated on the process drawings of the workpiece.
2. Consider potential anomalies that may occur during the forming process, such as collision with rivets or the machine, or collision between workpieces during bending.
3. Select the appropriate V-groove for bending workpieces.
The V-groove selection depends on the material thickness:
- When T ≤ 4mm, V-groove = T * 6.
- When T ≥ 4mm, V-groove = T * 8.
4. Note that when performing a 90° bend, the width of the "V" groove should not be less than 4t to avoid damaging the dies or causing workpiece rejection.
5. If the size of the bending edge is too small and requires a "V" groove below 4t, it is recommended to first bend a suitable obtuse angle and then use a larger "V" groove to achieve the 90° bend.
6. Thoroughly clean the cutting dies and machine tool seats to ensure there is no dust or debris.
7. Use upper and lower dies with a length of at least 300mm to remove them from the machine center. Pay attention to applying appropriate pressure to avoid damaging the dies.
8. Install the appropriate dies for the current processing requirements, ensuring proper positioning and securely fastening screws or clamps.
9. Ideally, position the dies in the center of the machine tool to ensure stable and continuous operation.
The selection process involves considering both the machine tool parameters and die parameters. Machine tool parameters include stroke, processing capacity, open height, and middle plate type. Die parameters include the type of upper die handle (matching the middle plate) and the pressure capacity (bending pressure).
Therefore, the selection process involves considering both the "machine tool parameters" and "die parameters."
Regarding machine tool parameter selection:
1. Selecting the die height:
Stroke (mm) = Open height - Middle plate height - Upper die height - Lower die seat height - (Lower die height - 0.5V + t), where t is the thickness of the sheet metal (mm).
When selecting the lower die seat, note that there are different heights available for different processing needs.
Different combinations of dies can be used to achieve different die heights, suitable for processing different parts.
Regarding die parameter selection:
1. Upper die handle type:
There are three types of upper die handles to match different middle plates.
2. Upper die shape:
Common standard upper die shapes include:
3. Upper die tip R angle and tip angle:
Commonly used upper die tip R angles include:
Selecting an appropriate tip R angle: Generally, R0.6 is used for materials below 3mm.
Standard upper dies have tip angles of 90°, 88°, 86°, 60°, 45°, 30°, and more.
The die angle should be smaller than the bending angle. For example, if the desired bend is 90°, an 88° die angle should be used.
4. Lower die type:
Common lower die types include single V and double V. Within these types, there are segmented and solid variations. Different die types are suitable for different processing needs.
In general, single V dies have wider applications than double V dies, and segmented dies have broader applications than solid ones. Our company typically uses double V and triple V lower dies.
5. Width of the lower die V groove and V groove angle:
The selection of the V groove in the lower die depends on the material thickness (T):
The V groove angle in the lower die should match the upper die.
