Once the selection of the bending machine is not appropriate, the production cost will rise, and the Press Brake Machine cannot be expected to recover the cost. Therefore, use the following 6 factors to guide your purchase needs.
The first important thing worth considering is the parts you want to produce. The point is to buy a Durma Press Brake that can complete the processing task with the shortest work table and the smallest tonnage.
Carefully consider the material grade and maximum processing thickness and length. If most of the work is low carbon steel with a thickness of 16 gauge and a maximum length of 10 feet, the free bending force need not be greater than 50 tons sheet bender machine. However, if you are engaged in a large number of bottomed die forming, perhaps 160-ton machine tools should be considered.
Well, assuming that the thickest material is 1/4 inch, 200 tons for 10 feet of free bending, and at least 600 tons for bottomed die bending (correction bending). If most of the work pieces are 5 feet or shorter, the tonnage is almost halved, which greatly reduces the purchase cost. The length of the parts
The specifications are quite: important.
Under the same load, the deflection of the 10-foot sheet metal folding machine table and slider is four times that of the 5-foot machine. This means that shorter machines require fewer shim adjustments to produce qualified parts. Reducing shim adjustments also shortens preparation time.
Material grade is also a key factor. Compared with low carbon steel, the load required for stainless steel is usually increased by about 50%, while the soft aluminum of most brands is reduced by about 50%. You can always get the tonnage table of the machine from the bending machine manufacturer, the table shows the length of each foot under different thickness and different materials.
Estimated tonnage required.
3. Bending radius of parts
When using free bending, the bending radius is 0.156 times the opening distance of the die. In the free bending process, the opening distance of the die should be 8 times the thickness of the metal material. For example, when forming a 16 gauge mild steel with a 1/2 inch opening distance, the bending radius of the part is about 0.078 inch. If the bending radius is almost small
To the thickness of the material, it must be formed with a bottomed die. However, the pressure required to form the bottomed die is about 4 times greater than free bending.
If the bending radius is smaller than the thickness of the material, a punch with a radius at the front end smaller than the thickness of the material must be used, and resort to the imprint bending method. In this way, it requires 10 times the pressure of free bending.
As far as 1-free bending is concerned, the punch and die are processed at 85° or less (smaller is better). When using this set of molds, pay attention to the gap between the punch and the concave mold at the bottom of the stroke, and enough to compensate for the springback and keep the material bent excessively about 90°.
For curved concave molds, the mold angle is generally 86 to 90°. At the bottom of the stroke, there should be a gap between the male and female dies that is slightly larger than the thickness of the material. The forming angle is improved because the tonnage of the bottomed die bending is large (about 4 times of free bending), reducing the bending radius usually caused by
The embossing bending is the same as that of the bottomed concave mold, except that the front end of the punch is processed to the required bending radius, and the gap between the convex and concave molds at the bottom of the stroke is less than the material thickness. Due to the application of sufficient pressure (about 10 times of free bending) to force the front end of the punch to contact the material, it basically avoids the rebound.
In order to select the lowest tonnage specification of the press brake machine for sale , it is best to plan for a bending radius greater than the thickness of the material, and use the free bending method as much as possible. When the Hydraulic Press Brake bending radius is large, it often does not affect the quality of the finished part and its future use.
Bending accuracy requirements are a factor that needs careful consideration. It is this factor that determines whether you need to consider a CNC bending machine or a manual bending machine. If the bending accuracy requires +1° and cannot be changed, you must focus on the CNC Sheet Metal Brake.
The repeatability of the slider of the Hydraulic Press Bending Machine is +0.0004 inches, and the precise angle of forming must adopt such precision and good mold. The repeatability of the slider of the manual bending machine is 0.002 inches, and the deviation of +2~3* will generally occur under the condition of using the appropriate mold. In addition, CNC Press Brake Machine price is faster
Quick-fitting molds are ready, when you need to bend many small parts, this is an undoubted reason to consider.
Even if you have a shelf full of molds, do not think that these molds are suitable for the newly bought machine. The wear of each mold must be checked by measuring the length from the front end of the punch to the shoulder and the length between the shoulder of the die.
For conventional molds, the deviation per foot should be around +0.001 inches, and the total length deviation should not be greater than +0.005 inches. As for the precision grinding mold, the accuracy per foot should be 0.0004 inches, and the total accuracy should not be greater than +0.002 inches. It is best to use fine grinding molds for CNC bending machines, and conventional molds for hand
6. Side length of bent piece
Suppose you bend 90° along a 5-gauge 10-gauge low-carbon steel plate. The bending machine must probably apply an additional 7.5 tons of pressure to push the steel plate up, and the operator must be prepared for a 280-pound straight edge to fall. Manufacturing this part may require several strong workers or even a crane. fold
Bending machine operators often need to bend long-edge parts without realizing how strenuous their work is.
Now there is a kind of feeding device suitable for workshops engaged in this kind of work, this device can be improved according to the needs of new and old machines. With this device, only one person is required to form long-edge parts.